What kind of switch to operate and bypass motion sensor security light?

I would like to be able to manually operate the light for when I need it to stay on continuously, and then have it operate on the motion sensor when I am away from it. Basically I have a motion sensor light mounted above the entrance to my shed/ workshop, and sometimes I need to set up my sawhorses outside of the shop to do work at night and the light is sufficient, but when I have been still too long, perhaps doing some figuring or whatever, it goes out. I don't want to have to continue to wave my hands about to get it to come on every time it goes off. Do I need a double pole single throw switch, or a single pole double throw, or what(is a three way light switch a SPDT- [single pole double throw] switch)? Is there a way to wire it to a single switch where I could flip it over to one side to operate continuously, and then flip the switch to make the light work off of the motion sensor when I have gone in for the night? Please forgive the ignorance. I just can't envision it in my head. Thanks.

Question by stevecinstrfme   |  last reply


What is the function of a SPDT switch?

Hi....my question is that what is the actual function of the SPDT (single pole double throw) switch and I would also really appreciate if any body also told that how does it work...Thanks..

Question by Wisaam   |  last reply


What kind of electronics could i scrounge SBDT (single pole double throw) switches from?

What kind of generally accessible electronics could I find SBDT switches (2) in, without having to go to the store?

Question by manmelvin   |  last reply


Is there such thing as a Normally closed spst relay? Answered

Im am looking for a Normally closed single pole single throw relay but can't find any when i google.Is it just because i am miss naming these relays

Question by legend4930   |  last reply


Cool Switch thing

My dad recently pulled a switch out from somewhere, and it looked cool, so I kept it. As far as I can tell it still works, and I believe it is Double pole double throw or something like that. I don't have any idea what to do with it though. D: Any ideas?

Topic by Rotten194   |  last reply


Motion Sensor to Control both Bathroom Light and Fan?

My bathroom currently has two single pole switches mounted in two separate wall boxes side by side with a single double-wide switch cover.  I want to convert these to motion sensor switches with separate vacancy delays for the light and fan so that I can let the exhaust fan run for about 5 minutes after vacancy while the light is set for maybe 30 seconds. Are there commercial switches that will accommodate these two functions in a single switch, or will i need to use a separate switch for the light and one for the fan?  Are there single double-wide wall plate covers that will fit side by side switch placement? Thanks.

Question by ValR14   |  last reply


Looking for the right type of switch to use....?

Hi, I'm trying to build something that might best be compared to a manually controlled speech timer with a green, yellow and red light. I only want one light on at a time, or all off. What is the best way to control this without having a single switch for each light? Am I describing something that would be classified as "single pole, quadruple throw?" Best place to find this switch? Thanks!

Question by Meeker46   |  last reply


Change batteries from serial to parallel configurations with switches?

I have a 5s4p battery pack.  The cells are 3.7 nominal voltage lithium ion cells.  In a serial configuration it is 18 volts nominal.  If I wire it in parallel it is in a 1s20p configuration and 3.7 volts nominal.  I had this awesome idea to use switches to change the configuration from 5s4p to 1s20p.  I want to do this because then I could charge whole pack with a 3.7 volt charger.  Better yet, I would not a balance charger. Once I got to trying to design the switch configuration I was amazed at how complex it would have to be.  The only way I can think of at the moment is to use 4 single throw single pull switches to isolate the cells and then use 5 double pole single throw switches to connect all the pos and negs together.   Does anyone out there know how to make a circuit which could work with with one circuit board and one switch?  It could switch between 18 volts serial to 3.7 volt parallel? Thanks

Question by Noblenutria   |  last reply


A/C Wireing Problem

I need a A/C 120v wireing diagram that show the best way to wire a Router, Blower & Saw so would run as follows. (1)Router & Blower at the same time. (2)Saw & Blower at the same time. (3)All off at the same time,can this be done using a Double Pole Throw Switch ? if so PLEASE send wireing diagram. :o)

Topic by kngokngo   |  last reply


can I use a rectifier as a dimmer for halogen light bulbs?

I am wiring a custom exhaust hood, and am wondering if I could use a IN5402 rectifier diode rated at 3 amps, 200 PIV connected in series with a 1.9 amp halogen light load, running at 120 Volts AC in order to dim the lights in the hood at about half bright? Wondering specifically if I will run into any problems with the longevity of the "dimmer", or the life of the bulbs? Also wondering if any one might know how I could make a very simple circuit that could slow a fan down to about half speed. I am using single pole double throw bat handle switches to make a high and low setting. High will just go straight through, and low will go through the dimmer or speed reducing module. Thanks rik

Question by wirepig   |  last reply


DPDT Timer circuit i.e. Momentary ON (+6v pulse) then OFF for 10 sec's then Momentary ON (reverse pulse)

I need to toggle a solenoid between 2 positions. It isn't spring loaded so needs to be powered between states i.e. a +6v and GND pulse to the coil then wait 5 to 10 sec's before sending another pulse but with the polarity reversed. Simple to do with a 'Mom-OFF-Mom' double pole double throw toggle switch e.g. JAYCAR Switch Tgl Mini CTR-OFF DPDT MOM CAT.NO: ST0358 but I would like to be a bit more automated.  Ideally the cycle will start at power on and then automatically repeat every 30 min's or so but if that makes it too complex, then a momentary push button switch could be included to manually initiate the cycle.  

Question by DavidB687   |  last reply


true semi auto gun crossover

I have seen and built both ednator55's true semi auto gun and bballkidx's hammer operated pistol. The pistol swings a hammer to hit a rod and the semi a auto rotates a connecter to move a ramrod. This is more of an idea than a question but could somebody try to make a double action type gun. It is semi auto because it rotates a connecter but at the same time hits the bullet with a hammer. This would be most similar to some revolvers. This is just throwing an idea out there but I would be very grateful if somebody built this. Automatic 5 stars in my book. The semi auto gun is weak but semi auto. The hammer gun is strong and single shot. The crossover gun doesn't have to include a mag but it would be nice. Pmgroundhog

Question by pmgroundhog   |  last reply


How does one choose the right 100k potentiometer?

I am building a pickup winder... a simple machine that winds hair-thin copper wire around magnetic poles.I need to build a 12V DC geared electric motor speed controller. I bought the following...12V DC 1000RPM geared electric motorLCD punch digital counter with a magnetic proximity switch12V Double-Pole Double-Throw (DPDT) ON/OFF/ON toggle switchDC12V 2A Power Supply Adapter: AC100-240V to DC12V I know that a DC motor controller can be purchased for around $5-10, but since I am brand n00b to electronics, I want to take the opportunity to learn as much as I can by building everything (or as much as makes sense) myself. I found this Instrucable on building a DC motor speed controller. It seems simple enough, however, when I go to the Digi-Key website and look for 100k Ohm pots... there are a lot to choose from. I do not care about form factor. I have no size restraints or aesthetics. I just need a knob... that I can turn... that will allow me to set it to zero, switch the machine on and have the motor not turn at all... then slowly begin to spin as I turn the knob up to 10, and it is spinning at its top speed (1,000 rpm). This is the motor, this is the power supply, this is the counter, and this is the switch that I bought for this project. According to the instructable referenced above, I need: an IRF3205 mosfet, a 100k ohm potentiometer, and a heatsink. I do not yet have the vocabulary to even properly Google "How to tell which 100k ohm potentiometer works with a 12V DC motor..." Can someone please point me in the right direction?

Topic by Dolmetscher007   |  last reply


Where to find a small form factor 12v Battery?

I am looking to build an LED light that can be powered directly by a 12v source or use an internal battery. I expect that the fixture form factor will be about 4" in length by 2" to 2.5" in width and no more than 3/4" in depth. Internally, it needs to fit two LED units (each draws 0.1-0.2amps and only one would be on at a time) that are 1"x1"x5/8" each, the inside component of a single pole double throw waterproof switch and the remaining space for batteries. I would like to fit the maximum amount of available capacity as possible in as small a space as possible. I am looking for battery suggestions - small form factor, 12v, preferably available via a regular source (i.e. don't have to be special ordered from China), low self-discharge rate, ability to withstand temperature extremes (specifically 120F-140F degree heat). I'll consider wiring up batteries in parallel and serial to get the charge depth and the proper voltage. Any thoughts? I looked at A23 12v batteries and 2CR-1/3N 6v batteries (wire in serial) but I'd like to find something with more available capacity. Also, I'd prefer a non-toxic battery, but will consider lithium, and the ability to be recharged would be a big bonus. I'm guessing there's nothing out there that would give me enough life to be happy, but I thought I'd ask. Thanks!

Question by kcls   |  last reply


Stepper Power Help???

I trying to design a cheap & easy (not ideal) bi polar stepper driver using the following components: 1. (1) A Bi-Polar motor rated at 12V 1A. 2. (4) 10A 250V Dual Throw, Single Pole Relays. 3. (1) Arduino UNO Microcontroller. 4. (1) ATX Power Supply. I have the switching logic all correct from the UNO to the relays, and I have all of the wiring correct on the power side of the relay. The problem comes down to shorting the PSU.My thought is the following, and I hope you gurus can either confirm, or correct my thought process (pretty please, and thank you). Please see the Attached Pic for a basic schematic of what I'm doing. 12v = 1A * 12OHMS 12v * 1A = 12 Watts Does this mean that somewhere within the power loop, I need a 12 Watt 12 OHM Resistor, to eliminate shorting out the PSU? If this is true, what would be a practical solution other than using a big exposed spring, bar, etc... that would by its sheer mass resist all of this power?

Question by abstract_genius   |  last reply


Got stuff, need ideas!

Hi everyone!  I work in industrial bearing distribution, and every now and then something falls into my lap that I get to play around with.  Today we got a bunch of bearings back that had been made slightly different than the customer had requested.  So, I've got a big box of these things.  There's nothing wrong with them, it's just that the little tapped holes are slightly misaligned and can't be used in the original application.  They are designed to press lightly onto a 5/16" shaft.  The tapped holes are 6-32 thread.  Also, I can easily get cheap 5/16 shafting and I've got a crate full of 5/16 single split and double split shaft collars. My question is, what would you do if had all of these little guys?  I couldn't bear to send them all to the steel recycling place, as they're perfectly good bearings and pretty neat to boot, but I'm not sure what to do with them.  I thought I'd throw it open to the group--any ideas?

Topic by depotdevoid   |  last reply


Throwies reimagined - Really I did tried :) :| :/

Seeing other forms of making interactive throwies, eg using microchips impresses me.However i think it is important that we try parts of the B.E.A.M philosophyhttp://en.wikipedia.org/wiki/BEAM_roboticsNamely keeping things simple, and avoiding the use of microprocessor.The component of a interactive throwie is that it has1. Power storage2. Trigger3. Circuit4. LED5. (optional) Power collection of radiant energy.I like to see more suggestion on ways we can address each issues.But to kick start the issue, can you see if my idea is feasible.essentially for my prototype not-yet throwie, I used a circuit from http://unconventional-airsoft.com/2003/11/16/momentary-fan-switch/#more-21to create a throwie that on sensing motion, doesn't flicker but turns on for a while.By ensuring that i use few and simple componants, i hope to keep cost per throwing down.Unfortunately my problem is that using a resistor to keep the capacitor from draining too fast from the base, actually decreases the voltage drop to an unacceptable level at the led.On my end it is unsolvable for the moment. Maybe you can work out how to make a cheap throwie, that can still do these functions or more.Any ideas how to solve this?Other Ideas for throwies1.Open and attach a switch to a barometer, to have a air presser passive trigger.2. A leave shaped pad with two conductors that do not touch, to act as rain sensors. (Resistance increase when leaf dries)3. Is sensitive to infrared radiation from side, so that the throwie is trigger-able by other activated throwies. (As well infrared devices)4. Has a short loop of coil to recharged capacitors, by outside induction.5. If activated rarely, uses a tiny single solar cell to charge capacitor.6. Has a hook to be easily collected for recycling. (Using a simple loop of wire on a pole [Like a dog catcher pole] )7. A single thermistors in series with led.8. A tricolour LED, and a Two light resistor. One LDR acts to sense if it is day an night, if night a low power light is activated. Only when an object strays near, and reflect light into another LDR, does the throwie get triggered at all.9. A throwie triggered by vibration.10. A throwie that responds to radio waves.

Topic by akimbo m   |  last reply


Linear magnetmotor - the basics for a beginner

Designing what is said to be impossible can be tricky, so I will try to give you some tips to reach your goal a bit quicker.A lot of people these days try to start with a wheel.Makes sense in one way as the final goal obviously is something that would rotate.However, considering angles in a rotating system is far easier with a usable baseline!We developed the liear motor well after any rotating electric motor.But only because someone already invented it for us.Making it flat was then more or less about finding a need for it first, like the modern highspeed trains on a maglev principle.If you want to make something move then it makes no big difference if you do it in flat or round.Flat however leaves you more options and much easier adjustments.And you will need a lot of the later...IMHO the best size and option for linear is the N0 model railway system.Tracks are only 3CM wide and second hand carriages to salvage the wheels is cheap.Either way, how would you start?We have multiple choices, like single row of magnets or double, maybe even tripple.Same for the actual magnet orientation.Flat, angled, attracting or repulsing...They all work if you understand how they actually work.Not the principle, the magnets ;)You see, a magnet always has two poles and without trickery both poles will be of even strenght, size, angle to each other and so on.Playing on a small and flat track with little resistance allows to use tiny magnets, like 5mm disc ones.If you follow the common concept of two magnet rows either side at a slight angle then you are half way there.People spent a lot of time trying not only to let the cart being attracted by the first magnets but also to let them pass out at the other end.In case you wonder why:Being able to be "sucked" in means you will have some force pulling on your cart from the next stage.Being able to fully pass through and preferably gain speed, means the cart would go from one set of magnets to the next - motion is accomplished.Let me give you my personal favourites for 5mm disc magnets:1. The rows are at an angle of 4-5° like a slim V-shape.2. Same as above by with the orientation changed by 90°The first basically means you have the magnets facing up while in the second you would have them mounted vertically.Both have good and bad sides and I think it is easiest to start with the first option.Here you would have a row of magnets at a slight angle either side of the track.Lets say it is all pointing away from you, then the north row would be left, south row on the right of the track.If you start narrow or wide depends if you want attraction or repulsion forces to work with.Again, it makes no big difference really, just a different way of operation, most seem to prefer repulsion though thinking the forces are greater - this is not true though ;)A very often copied way of mounting the working magnet (s) on the cart is by placing a magnet with south facing down on the left and one with north facing down on the right of the cart.Here you have the big problem of manipulating fields.The forces are quite strong and it seems the obvious choice but should be left for the advanced classes.Let me try to explain:No matter the site of your work magnet it has a very narrow acting field.Means you have a lot of attraction forces going only downwards and not providing any energy to move your system ;)If you orientate a magnet (stack) so north faces to the right and south to the left on either side of the cart you have more options.If the stack or single magnet has the correct length to match the angle of the magnet rows then a funny thing happens.Assume the outer most magnet is at about the same distance from center as the first magnet in the row.Means the inner most and opposing one is further away and the attraction forces gain the upper hand.While moving along though it moves away from the magnet row and whie still gaining force the last magnet in the row stops the cart dead center.This is the common scenario you see on the web when people try and fail.Now if you change the length of your working magnet and position in relation to the magnets in the row you can use the changes to your advantage.You can add slim disc magnets either side of your stack and observe the change in behaviour and where the cart starts to be repelled or gets stuck.In a bad case it starts fast but then stops with a big wobble back and forth.The perfect balance and size means the cart is attracted once it comes close to the magnet rows.There should only be a tiny sopt of very little repulsion right before the cart takes off.Like a hair trigger on a good gun if you know what I mean.It should then see some accelleration till about magnet 5-7 in a row of 14.From there it should level out and roll trough and keep rolling.I assume your first attempts now get you to the point where you cart start really nice, slows down a bit and seems just to miss a tiny extra push to make it out.It it shoots to the last magnet in the rows and then settles back to one or two before the end you are close!We have now two basic ways of manipulating the magnetic fields in our favour, or to "cheat" phsyics.Closing the gap.You will have realised by now that you need at least two stages for your system to be tested properly.Preferably 3 to get a 120° angle in a rotary conversion, but 5 would make sure there is hickups.This also means distance is now something to play with.Remember the pull before get at the same level with the first magnet in the rows?This is the first force we utilise by bringing the second stage at a distance CLOSE to take over the pull.Close because we don't want it to pull the cart out just like that.It would create a big "bump" and in a rotary system massive and unwanted vibrations.Instead we weaken the last magnet in either row.We still want to keep its pull but not so much the holding force that makes our cart go stuck here.Placing a magnet orientated in the same direction as your rows at the end of the row will change how and where the field of the last magnet in the row goes ;)Just to be precise: If the magnet in the row is north up and south down then the added magnet should have the poles 90° to that and in the same direction as the row.Depending how high, how close and with wich pole you place it the fields will change.You want to lower the locking force by at least 50% here - that will be suffient to overcome the holding force and gives the next stage a good chance to take over.It can also help to provide a sacrificial pole below the last magnet in the row.Again if north would be facing up then the lower magnet would also face north up but with a small distance to the upper manget.Ok, what happens here exactly?If I would want to be precise here you would need to read an awful lot, so make it simple...The lower magnet provides a way for the upper magnets south pole to get somewhere else instead of back to its original north pole.It also means there is another north pole "pushing" the north of the upper magnet more flat at the bottom half.This weakens the field strenght.Distance is key.The added magnet at the end does a similar thing.It provides attraction or repulsion forces that affect the field shape of the last magnet in the row.Imagine you have north facing towards the last magnet:You would push the last bit of the field up while also providing a very sharp end instead of a big round shape.The south pole of the last magnet also gets attracted by this added magnet, even more with one magnet below it.With those two added magnets you should be able to fully overcome the binding effect stopping your cart.It won't start and keep going when you let go of it half way down the track though, you need to start with the first magnet or give it a push to overcome the first binding effect.After that momentum takes over.If it really is that simple then where are all the successful videos about it?They are out there, you just need to look quite long for them.Most people still literally think only linear.A magnet has north and south and we can't change it - but we can...With field manipulations as above and shielding we get so much more than what physics currently dictates.Keep in mind that adding shielding under your rows of magnets will also affect how all works together ;)Some people forget this when using ferromagnetic things way too close to their testing area.Distance is also vital to keep in mind when experimenting.The closer two magnets are greater their forces to each other.You can utilise this for example by lowering magnets that seem to be far too strong in your configuration and cause a binding effect ;)And as said, shielding is nice thing for triack too - imagine what would happen with sielding on the sides of your magnet rows... ;)Make a negative into a positive!Extremly strong binding forces at a certain point in your track design can mean you might be able to utilise it instead of trying to waste it.Added magnets can divert the field to quite some extend.Shielding however can also direct them somewhere else - like in the core of a transformer where it all goes in a great circle.Even strips of shielding connecting magnets from one row to the one on the other side of the track can be utilised.Like that you turn two small magnets into one long one with twisted poles at the end.Provides more field strenght too and makes it good for areas with little to no attracting force to the cart.Then there is bigger design...Some people add a center magnet.With one on the cart and one in the center of the track you can create a cancellation field.The rows bind while the center magnet wants to push.If place where there is still enough forward momentum or even acceleration but close enough to the binding magnets it is possible to greatly lower the binding effect.But keep in mind you need to consider the added repulsion or compensated the field so it is most active towards the moving direction and less strong to where the cart is coming from.Advanced manipulations.You can machine magnets, sandpaper, file, grinder, CNC....Imagine you cut a square dice magnet from one corner to the other.Depending on how you have the field orientation you can end up several variations.But if north faced up in your dice then it will still face up in the cut pieces!Cut a pyramid and you end with a big flat south pole and a pointy north pole - and with extreme field strenth in this pointy bit.Similar story with half moon shapes.Imagine you machine a flat block magnet so you have a half moon with its pointy bits facing down and big round bit up.If north was up in the block and you shape the moon correctly then you end with two strong south pole points and a north pole that is strongest right between those points.Why is this so interesting you might wonder?Imagine you already know a magnets pole does not care if gos back to its own opposite or that of a different magnet.Then you also know you can machine and shape magnets to your will.Now imagine that for a change:Precisely machined pyramids that have the top chopped off.All tops in this example facing being the north poles and big bottom south.If you then machine a precise iron core block you make a nice cube.With magnets we need really good glue and a good press to make it happen.But if the center core is of proper size then we end with a block magnet that has a south pole on all sides.Of course to be 100% perfect we would need a zero tolerance gap but good glue and high forces can come quite close.Works as a sphere too but would even have clue where to start to machine the magnets LOL

Topic by Downunder35m 


How can I modify this circuit to sequentially turn on LEDs in parallel, while avoiding voltage drops? Answered

I have a single pole, 12 throw rotary switch which I want to solder to a set of LEDs so that rotating the switch clockwise lights more LEDs as follows: 1 = 1 Red LED 2 = 2 Red LEDs 3 = 3 Red LEDs 4 = 4 Red LEDs 5 = 5 Yellow LEDs 6 = 6 Yellow LEDs 7 = 7 Yellow LEDs 8 = 8 Yellow LEDs 9 = 9 Blue LEDs 10 = 10 Blue LEDs 11 = 11 Blue LEDs 12 = 12 Blue LEDs Since there will be a voltage drop across the diodes, the LEDs at the start of the chain will get progressively dimmer, and increasing the voltage would blow the LEDs in shorter chains. One modification I know I could already make would be to not use the first 4 diodes on the yellow LEDs, and the first 8 diodes on the red LEDs, as a minimum of 5 yellows and 9 blue will be active for each position. This still leaves a maximum of 3 diodes in each chain, which I still think would cause the lights to be much dimmer. Another solution I can think of is to have multiple wires coming from each terminal of the switch, each with their own diode, which would ensure all active LEDs had the same brightness (I'm not sure if this would cause the whole chain to be dimmer than shorter chains or not). The downside is this would need  31 wires rather than 13, and that's only if I bridged together all the shortest LED chains of each sequence: individual wires for absolutely every position would mean 79 wires+diodes). To put this in context, I want to create the health bar from Dead Space 3: If you can suggest a way of improving the circuit, or totally re-designing it, it'd help me loads! Thanks!

Question by Shadow Of Intent   |  last reply


UHF CB radio antennas or scanner antennas anyone?

For a while now I am back to experimenting with various antenna designs for my UHF radio.Started as something entirely different but who cares LOLAnyways, we usually have either a standard whip antenna or a vertical dipole design for mobile use, like on your car.This is a very good design for both types of antennas, mostly due to the short wavelenght compared to the "old" 2m or 27mHz CB radios.Fun fact for at least AU in this regard is that back in the day everyone jumped onto UHF to get away from the overfilled chatter on 27MHz, now the old 2m band is basically dead except for marine use.One thing I really miss on UHF though is distance!Line of sight communication sounds fine at first but then you really have to realise the limits once out and about.As a result we often have to choose between a high gain antenna or a stubby for going into the mountains or being in a convoy.Only way out seems to be the golden middle by opting for one of the 4.5 - 6-5DBI antennas.Neither solution really satisfies me though :(To get around the limitations and have some fun again when sitting high on a mountain I compared various commercial antennas I had.You know, pick someone with a weak signal coming in and hope he hears you and has some time for a chat.Turned out there is not really that much difference in terms of receiving a signal.Quite huge differences though when it comes to the other side being able to hear you!So I jumped onto a basic SWR meter and actually checked my so called factory tuned antennas - all but one were way off the charts here.At least if you are like me and like optimised instead of compromised antenna systems.A Standing Wave Reflection ratio of 1:2 or even 1:2.5 is seen as very acceptable thing on UHF for some weird reason.Back in my glory days no one I knew would have accepted anything above 1:1.3 for his 27MHz system, be it mobil or a station at home.Sure enough, repeating my long distance tests a few days later with tuned antennas resulted in far better results.An antenna for long distance calls or emergencies?!The easiest way to get more distance on UHF is obviously getting the antenna as high as possible.From a nice mountain top you have it way easier than in any urban areas for example.Explains why so many of the long and sturdy antennas are just simple dipoles on a long pole.If you ever checked the feedback for these double quad TV antennas you realise they are literally in the same frequency range.Similar story for all the Yagi antennas for our TV sets that you find on so many roofs these days.Only problem with them is that they usually don't give a damn about transmitting qualities.And of course that they are usually providing around 300Ohm instead of the 50Ohm our radio expects.A TV needs 75Ohm and a balun is used to provide a isolation as well as a matching for the TV.Needless to say I could not accept this ;)My first design was made from aluminium foil glued onto some printed and stiched pages for a double quad.1MHz bandwidth is quite narrow, so the basic square design with about 13.8cm for the sides of the squares was easy.To my surprise by just adding standard RG58 cable this design was very close to 50Ohm already, I had around 60.A few glue sessions later I was able to match it to 52Ohm - close enough for test.Did not want to risk anything with my expensive Icom so I used my cheap Baofeng handheld for the initial tests.Indoor mind you...To me disappointment I seemed to be unable to pick up anything.So let the sanner run and waited...After being bored enough I decided to pick, starting with the antenna and when I moved it the handheld suddenly had a clear signal.Desperate as I was I grabbed the radio and waited for the chat to continue - nothing again...Then it finally hit me: The double quad is quite directional....Sure enough by just turning it slowly I was able to pick up chatter on various channels.Once brave enough to risk it I even got confirmation that people about 10km away could hear me just fine.Time to scale it up a notch...Next design already had the directional problem included as a design feature.I added a director in the front and a reflector in the back.The endless hours of glueing and cutting were replaced by using 12mm wide copper tape and sturdier cardboard.A test with my car on a little "mountain" and the antenna on 2m pole mounted to roof rack gave me, for the first time ever, conversations with people that were over 30km away.I am currently trying to make the entire thing omnidirectional.The omni quad....If you take two double quad antennas and mount them at a 90° angle you end up with very nice 2-lobe pattern, 4 lobes if you don't use a reflector.Problem here though is that these designs really mess with your antenna matching.Not to mention that using it while driving only works at quite low speeds.One day I will do the final design in stainless steel wire though...Anyways, using the directional properties to get an omnidirection radiation pattern meant using 4 seperate antennas with a reflector for each of them.Still left a few dark spots at short range but otherwise really nice for long distance if you don't want to constantly turn your antenna.Getting 4 antennas down to 50Ohm on the connection to the cable was painful to say the least.The problem of taking care of distances to be in the sweet spot for the 477MHz range also meant the design ended up to be quite bulky.One of my lightbulb moments providing good ideas caused me to use one reflector with a double quad either side.Worked almost fine but again provided totally different values to somehow match if it ever should transmit a signal without damaging the transmitter.Obvious conclusion was to buy a new roll of copper tape and to try to get four single antennas into one "housing" without stacking them.Bad idea here was to cross the antennas :(Better idea was to make 4 pyramids out of carboard and aluminium foil.Sadly this resulted in a failure because the 4 sides of the pyramid reflect the signal not flat bt at their corresponding angles.Had to make it really big and use 90° angles, resulting in the signal being reflected like light in these cat-eye reflectors on your bike.After wasting a few days to create the real thing it turned out to not really work properly for the reception already.Even close range signals came in really distorted.I guess the double reflection meant the phase is shifting and cancelling out what the antenna gets.My last desing idea for testing will be with a different approach.Instead of 1/4 Lambda elements I will use small 1/64 Lambda elements.Only about 2cm long means that matching is pain in the behind but if the purpose is just receiving it should be fine.The reflector will be four flat sides like a box with antennas in front of the sides and the cables joined in the center.If you like to fiddle with antennas and don't mind trying a weird looking base antenna on your roof I might be willing to write up a short Instructable based on my designs - let me know in the comments....By the way: it is quite easy to desing this for the common 2.4GHz Wifi bands ;)

Topic by Downunder35m   |  last reply


Ceiling fan generator mod to the max

I stubled upon several mods to convert a standard ceiling fan into a more or less usefull generator.So if you are looking to go this route then I might have some nice improvements that can be implemented.People like these mods for some weird reason, despite the fact that it requires quite a bit of extra work to make them weather proof.However, when it comes to the fundamentals then to me it looks like some folks out there are missing out.On the available power that is...Always the first step for a mod like this is to replace the induction ring with a lot of magnets.Second step usually is to remove a lot of the coils, especially the inner ring.Now, these two stator designs are common for fans with two speeds.Those with three or even reverse might have a different configuration!Lets start on the magnet part:The recommended way of placing the magnets is by creating an air gap as small as possible - makes sense.But then it is always the same amount of magnets as there is coils - and the spacing is also the same as for the coils.In the general generaotr design world this configuration is prefered as it allows for the best performance.If you dare to go a bit further and cosider how the magnets react to the stator configuration then you might want to consider a different option.You see, these two sets of coils for two different speeds mean just one thing:A different amount of poles is created, with the outer ring having more poles than the inner ring of coils.The core is split around the coils, not just to allow the windings to be made but also to provide independent paths for the magnetic field - resulting in the two pole configurations.Amounts differ by diameter, power level, manufacturer and so on.What is always the same is that the inner ring has less coils and that the outer segments of the poles created have even spacings.In the normal mods you see posted these gaps in the core for the outer ring are closed by inserting lamitaed pieces from some old transformer.And you end up with ONE usable coil configuration and ONE power output.The slightly advanced mod uses the inner coil to add some load depending on the speed to prevent spinning out of control in high winds.If you try a normal DC motor with permanent magnets than you will notice the strong binding forces, it is like the rotor sticks in certain places.The better ones use and uneven configuration to reduce this binding effect ;)In my mod the magnets are selected in size to almost be the same length as two stator poles next to each other.This allows for the best induction while still allowing "to experiment".Bringing the magnets and the coils into play...As said an exact match of the number of magnets to either coil ring is not ideal.The prefered option is to go somewhere in between.For example:Outer ring has 18 coils then the inner ring will have 9 coils - exactly half.360° divided by 15 make a nice 24 degress per magnet.But with 12 magnets you get an even 30°, which is far easier to deal with.16 magnets at 22.5° is another option.So, what does that exactly do for us?The bad thing is we get slightly less performance if you only see the standard mod with one coil ring.The good thing we get far lower binding forces and through that the thing will even spin in very light winds.Adding both coil rings with a suitable rectifier however results in a pulsing output of two sine waves.With just the rectifier we get a ripple that is easier to deal with through a capacitor.The extra power available is in the range of about 40% and make more than up for the "reduced" amount of magnets.Going the extra mile once more ;)Having created a much fancier ceiling fan mod now you might wonder if there is not a way to get even more out of it.And there is.For example by utilising a gear system or belt to get a far higher rotational speed on the generator than what the blades would provide, prefably then with quite big blades too and an automatic break for high wind conditions.With the reduced binding forces the generator will be happy to spin at quite high speeds in low winds.Downside is that you will need to build a far more sturdy bearing housing.In return though you get more stability and durability.You can do the math yourself based on the number of poles per ring and magnets to get the output frequency based on the RPM's.Perfect would now be to use a switch mode power supply configuration to directly transform the provided output into a stable DC per ring.And yes, it is possible to use mechanical systems to provide a fixed output speed from the blades to the generator - but way to complex and lossy!Lets do some lame math with no regards to realities:If the original fan would spin at 100 RPM at full speed than we could say our generator should provide the mains voltage at about 100 RPM.Keep in mind we utilise both coil rings and not just the high speed one!Geared and with the blades spinning at 100 RPM we might get as much as 1000V from this little generator....And even with the lower amount of magnets we migh see frequencies above the 500Hz range.The good thing now is that normal iron core transformers can still operate at these frequencies.A bit lossy in the upper range but acceptable for the purpose.Put simple: A 10 or 20:1 transformer per coil ring would provide us with a far more suitable output voltage and much higher amps.If you made it to here than you certainly wonder about other magnet configurations.Checking the stator configuration you will by now realise why I selected the magnet lenght accordingly.The magnets "activate" one coil after the other.The spacing between them means there is always some overlap where the magnets only cover one half of the stator for a coil.This is ok because we don't really have to worry about the resulting messy output.Ideally though you would want to have a magnet activate both coils, the inner and the outer at the same time.What we did though was to make sure that at no time more than ONE magnet fully covers more than ONE coil!It is the best option to cover both coil sets while minimising binding effects and increasing the avialable output.To go the last step you would need to invest a lot of time re-winding all coils :(You don't want to do this unless you have the means and no friends and family that might miss you for a few days....I found a far simpler way to change the coil configuration, although it is not as good a re-winding.So let's go full scale shall we?Ceiling fan reconfiguration!If you take the usual 18 to 9 configuration than one thing jumps to mind reight away: 3-phase power!Cutting the wire that goes from coil to coil might not always be possible and if it is then you need to know how to handle it.Magnet wire can be hard to solder.Burning the coating off results in corroded copper that is even harder to solder.If you are lucky though than a reall hot soldering irong will be able to melt the coating.The flux from the solder will start to cover the wire from the cut and the solder will follow.If not then using some fine sandpaper and time is the other option to remove the coating...Ok, you seperated all coil and have two wire ends per coil?I hope you did not cut off the ones going out to the actual connections to the outside world ;)Properly solder each wire end and take your time to check it is really proper and not just a few spots.Mark or number the coils on the rings!For the inner ring we have 9 but need only 3, so we start at one connection to the outside world and check if this connection is on the outside or inside of the coil.For this example I assume you picked the one that goes to the outside of the coil.Connect the inside wire to the outside wire of coil number 3, assuming we start with 1 here ;)From the inside wire of 3 you go to outside of 6 and the inside is you first new output connection.Do the same with the remaining 6 coils and where needed add the required output wire.It really helps to have wires with three different colors here, one color per new coil set.Note which color corresponds to to the three coils used!!!The outer ring with 18 coils is sightly different here.You see, we want a "flowing" magnetic field that makes best use of the new coil configuration!We can not simply bridge them in any way we feel like without considering how this might affect the electrical side of things.As we now take the approach of a three phase system it makes sense to use a more suitable magnet configuration as well.So before go to the outer ring of coils lets have a look of the best option for the magnets first:The stator packs are evenly spaced in our example and will alow us to use 18 magnets.This provides the best performance with the downside of a higher binding effect, but we need this configuration to get the best possible output.As said at the start I selected magnets that are just shy of being the same length as the corresponding stator segments.In a "free" setup these magnets would now be quite hard to place in a makeshift ring.Even harder in the original casing.A 3D printer certainly helps but some common sense too ;)Wood is easy to work with and if you select the right stuff than making a suitable ring to hold your magnets and attach to the drive system metal parts is not too hard.Bar or brick type magnets can be quite easy be utilised on a wood setup :)The key is that you add Flux Capacitors - sorry couldn't help the reference to Marty....What I mean is to add some magnetic material between the north pole of one magnet and the south pole of the other.Lets say your magnets are 15mm long and have a spacing of 5mm.Then a little plate of 12mm would be next to perfect.This plate needs to connect the magnets on the backside, the side facing away from the coils.Use a dremel tool or what you have to first create slots for the metal strips or bars, then the same for the magnets.Glue in the metal first and once set add the magnet, making sure the always go north to south with their alignment.Ok, and what does this do for us?I hope you are not one of these persons who starts building while reading...What we created now is a shortcut for the magnetic forces.The field between the magnets is severly compromised in terms of being usable for the coils.We do get a much soother run though...I only did that to have some fun and check if you paid attention - sorry :(What we really want is an effect similar to what you see on a loadspeaker magnet that is still in its metal shielding.A ring magnet with one pole on the inside and one on the outside is used here.The shielding provides a path for the magnetic field that is not going through the speaker coil - hence the little air gap for the coil.If we do the same then our efficiency will be going up quite a bit.Take two identical steel parts, like some butter knifes, and prefarbly a force gauge.If you try to pull your magnet at a 90° angle from the blade you will get a certain reading for the required force to lift it off.Most people now think that this would be the max a magnet can hold.So take the other knife and place the magnet between them.If you pull the knife off with the gauge now the reading will be higher than what you get from just the magnet ;)Taking that to our model and keeping the field lines in mind we now know that we could even use slightly longer plates if our magnets happen to be a bit short :)Just place them right behind each magnet !Back to the outer ring of coils....With 18 magnets we get an even system for both coil rings.However we want to make sure that our output waves are syncronised and not at random order.We need to combine two coils to be back on a 9 coil configuration as on the inner ring.The other option is to provide two sets of outputs for outer ring, resulting in 3 3-phase outputs.Both have their pros and cons....But if you check the 18 magnet configuration ina ction over the coils it becomes clear that combining two coils the usual way is possible but also that our inner ring does not get a proper north south action from the magnets!Only the outer coil ring works properly!For the inner ring we never get only a north south combo, instead a lot of mixes.Did I mention to read first? ;)Of course we can only use 9 magnets in our configuration, but at least I did not traick you on their size....You see, we need to account for the fact that the coils are not just evenly spaced but also that all configurations in terms of coils to stator pack are doubles or halfs.Makes a lot more sense if you know how these asyncronous motors work :)With 9 magnets we actually get both inner and outer ring coils activated properly.Plus we now have the benefit that there are always twoouter coils in sync with each other.Means apart from the same way you wired the inner ring you make this addition to the outer ring:"One" outer coil is created by going from one coilinner connection to the outer connection of the second after this, skipping one coil.The resulting output is again just 3 phases but with double the output voltage.The key is to again take notes of how you connect and wire the coils - and the colors used for the output wires!Let me give you an example for the correct order:I we take the number 1 coil on the inner ring then coils number 1 and 18 would be next to it on the outer ring.You want to combine 1 and 3, 2 and 4, 5 and 7,....And you want the resulting three coil packs and wires colores to correspond to the inner coils in the same order!That is true for the always same way of combining coils from the inner to outer connection - or the other way around but never mixed!Ok, we have done the magnets and the coil configuration now properly, no jokes this time!With two simple 3-phase rectifiers we get two DC outputs that can be combined or used seperately.As we end up with roughly double the output voltage on one output but all coils are the same it makes sense to treat them independly.For those who wonder why:If you add a load than one coil system would take a higher loading of it.Meaning while one coil set is stll fine the other will already start to overheat - if the load is too great.So we use two rectifiers with some filtering.In the basic form just a really big electrolytic capacitor of suitable voltage or a full LC filer system with multiple stages.Either way we can now utilise some better DC-DC converters to get going.Considering the equal max watss the coil rings can handle it make sense to include some current limiting.A good converter will provide this option.Both converters can now set to the desiered output or with some added protection diodes and adjusted properly to the same voltage combined for just one DC output.Compared to the standard mod of removing coils and bridgning stator packs the resulting output power in overall Watt will now be about 40-60% higher - depending on the model and quality of parts.Special words of wisdom:Consider the orignal max speed of the fan when used as intendet - see this as a theoretical max output that equals your mains voltage.Just ignore losses and such things - better to be safe than sorry.It becomes clear that it quite possible that your output will be far higher than mains voltage and that you need use transformers for the two 3-phase systems so you can use standard DC-DC converters, which have a max input voltage of around 50V only.This means your converter must be able to handle the higher amps!The fan might have only used 100W or less than 500mA but at high speeds and a ratios of lets say 10 to 1 for the gearing high wind speeds might get it up to over 5 amps on the transformer outputs.Please do the math first for your gear system in relation to the max wind speeds you want to use with your blades!If in doubt use a converter that has some reserves to offer, especially if you aim to charge batteries as quickly as possible.The most vital part however is to ensure that all previously cut wires are isulated properly!!!Magnet wire of the standard kind is good for about 1000V max, so don't drive it higher!Heat shrink with a hot glue liner is prefered but hard to apply in these thight spaces.Since nothing moves consider using long enough wires for your connections so you have enough space to solder without affecting the heat shrink tubes.Liquid insulation or rubber is the last option and should only be used to finalside the heat shrink security measures.Best option once all is confirmed to be working fine would be to make a custom mold and to fully enclose the staotr pack and wires with casting resin or an insulating casting mix.Make sure to keep the output wirese free at the their ends ;)What if I don't want to build a complicated three phase rectifier and just use a single phase system as it was?Firstly chances are your coils are already connected in a three phase configuration, just all in series.But working out a suitable magnet configuration to suit this is much harder if you want to use both sets of coils.In a series configuration like the original you also have to accept the losses from these connected coils.The higher the overall resistance the lower the possible output ;)Main problem however is to get the magnet working properly.The standard 9 or here even 18 magnet configurations still works, especially with the added shielding from behind.But the coils also produce a magnetic field, which grows with the load.Means that an top of all you also have the coils working against the magnets and create even higher losses.Explains why the simple folks prefer not use the inner coil set if they go with a single phase system.So either accept the losses and just use the outer coils or do it fully and get far mor output.And by the way: a 3-phase rectifier modlue is only a few cents more than a standard bridge rectifier ;)Ok, and why do I bother to write all this?People like to tinker but most don't really invent.Following some simple instructions is easy, trying to work it yourself much harder.The reward however is that you actually start to know what you are doing :)And what works for a ceiling fan can be used for these ring style washing machine motors too ;)Anyways...We need to get back our roots.Start thinking for ourself again, work things out instead of just looking them up.If people would be aware that a simple ceiling fan could provide about 3 times the output power of its rated installation value instead of only just about half......Super strong magnets allow real output even without re.winding all coils.And what works here works for other things too.We only learned to use magnets in a striaght way because we can not bend them.But we can bed the magnetic field lines to our advantage!The simple shielding used in this mod is nothing more than a shortcut to enhance the field strenght where it is is needed.By a simple coil modification we basically bet two electrical generators for the price and size of one.Apart from stating how easy it would be to place multiple stators and magnet rings into one generator the magnets itself also allow for even more output.If you ever played with hook magnets or speaker magnets then you know how much stronger they are compared to just the magnet once they seperate after hours of fun for you.Imagine you would replace the single bar magnet with two block magnets that are joined by a magnetic shunt like out simple shielding before.If the magnet blocks now would have a slightly smaller footprint than your individual poles:Imagine you create a hlaf ring shaped magnetic connection between the two blocks that also goes aruond the outer perimeter up to the outside of the magnets surface?I mean the surface facing the stator poles?Damn your imagination is good, yout it right away!Of course we would then have a magnet that allpies its full strength focussed onto each pole of a coil!And of course the resulting field would be far stronger than just using the magnet blocks itself and still significantly higher than just adding a shielding or connection between them.The affect of the next coil coming is also drastically reduced, which in return also increases the efficiency.In terms of numbers:If a fixed neodymium magnet would provide us 100$ field strength as the base point with no shielding (just the magnet blocks alone);A fully shielded and connected system, like in a hook magnet combined with a U-style magnet, would reach above 400% here.....Adding witchcraft to the mix ;)Although I know better I just assume some of you have now a working double-three-phase-ceiling-fan-generator.And that would mean you also have some fans to spare from your long experiments.Modern ignition coils seem to have nothing in common with our ceiling fan or resulting generator.So why do I try to use them anyway?For the ignition only one polarity is prefered so the spark works and travels as intendet.Means the "wasted" energy from the othe half of the pulse seems to be lost.The electronics do a lot here but magnets too ;)The core of the coil has magents at either end, turning it into one long magnet that still has the right properties to act as high voltage transformer system with the coils.The coil appear to be pre-loaded and with the ignition pulse it has to overcome the magnetic field pre-set by the magnets.And when the electrical impulse is off the same magnets also accelerated and increase the resulting fall back impulse - which provides the spark.Unless you have a suitable laser cutter or simlar cutting tech available somehow it will be hard to modify the metal plates of the stator.But if you could...Imagine you could add magnet inside the plates that are inside a coil.The same pre-loading would happen.Does not really help in terms of adding outpur as our rectifier would suffer badly here.It does give ideas though...Shielding works fine for the magnets, same for field shaping.Electromagnets use the same techniques...So why not use some leftlever transformer cores to add more "shortcuts" for the coils?Strips of transformer core sheets added either side of the coils increase their field strenght and result in better output!Three packs either side of the stator pack are usually no problem.Now take your leftovers and do a standard mod.Compare the max output on the same windmill with what you get from my mod(s).The only real magic I used here is that I actually bothered to combine multiple and already used methods to drastically increase the available output of an otherwise utterly useless generator mod ;)Warnings:If you take the above mods serious and to the their extreme than it is imperative to make sure you have safety measures in place!Assume the lowest rating for the magnet wire and if in doubt stick with a max output voltage of 800V.These mods are potentially lethal if you don't follow what is common sense to everyone dealing with high voltages for a living!Most people will start without any gearing or belts and use the wind directly.Even here it is easy to get far higher RPM than what the thing ever did under your ceiling.Without some fixes you will need transformers to reduce the output voltage accordingly.Only other option is to limit the max speed to what your DC-DC converter can handle.Making mistakes with mangets can cost you a lot of time and work, make sure to mark their poles somehow to prevent putting them in wrong.If in doubt then double check!Always keep in mind what the magnet wires and your connections can handle!You don't want any arcs or overheating.Some added electronics to monitor wind speed, rpm's, load and temperature of the coils can turn out vital once you upscale.Before letting your new generator do its thing make sure you tested all to the max!Use a drill or so to speed it up and check the limit regulation for the converters.Measure the actual volts and amps going through your coil sets at assumed max speed and max load.Monitor the coil temp while doing so to ensure nothing is out of limit!You are kidding me here right?A scrap ceiling fan shall provide more output as a wind generator than what was used to spin it as a fan?And of course I need not one but two 3-phse transformers...Pretty clear it is all a fake because nobody could replicate any of it unless limited to what the converters can handle...Didn't I say to think outside normal restraints already?A single phase transformer uses two coils in the most basic configuration.For example one side for 240V and te other for 12V.But some of them are more efficient than other ;)A 3-phase transformer uses 6 coils, two for each phase.And there are plenty of standrad transformer cores out there that would allow us to use this configuration.The worst being the MOT, or microwave oven transformer.Very lossy for a reason but good as an example as these have three core stems ;)Now that you see that you will that a lot more transformers actually allow you to replace the two coils with 6 ;)Ok, but why not use a rectifier first and not use a transformer or two at all?The resulting output voltage will without a gear REDUCTION be much higher than what a cheap DC-DC converter can handle.And at such speeds the effiency would be very bad too.You would need huge capacitors of good quality to deal with the now more impulse like output.And considering the primary side of the transformer does not require anything thicker than the wire on the coils of the fan...Not hard at all to find some suitable tansformers to salvage - or to use some nice ring transformers ;)No kidding around, just facts and possible options you might want to explore.Does that now mean I get free energy?Sure, if you mean you get the free nergy from the energy of the wind at no cost.No if you think a ceiling fan could ever power your house.Internal resistance, size and wire/connection properties set our limits.Not to mention that they are designed to be dirt cheap.If you are in a windy region and assume a realistic 300W minimum output from a 100W fan then adding more stage multiplies this.These fancy upright windmills are not just powerful but also would allow to use one modded fan either end.If big enough and with enough wind force throughout the year you could just add a second or third stage to ech end.With 3 on both ends the resulting output would then be suddenly 1.8kW per windmill....And all from scrap parts with only the costs for the magnets...No wind? Then use water....None of it? Get some greyhounds and build a big hamster wheel :)You get the general idea I hope...

Topic by Downunder35m   |  last reply


Magnetmotor - really impossible or just supressed?

When someone starts talking about a so called magnetmotor than most people judge right away.Laws of physics, perpetuum mobile is impossible, magnets are static....We all know the limitations nature puts on us... That however did not stop quite a few people since the 1950's to build working magnet motors. Or, to be precise: To make the claim, show them and then somehow disappear. A few though seem to have survived and even claim to make good business. Securely closed machine, stellite tracking and 24/7 online monitoring. Either just a bad and long running hoax or a real attempt to keep a secret secret. Even the somewhat famous Yildiz motor showed off around the world only to disappear.Some like them, some don't. Either way all this sounds like the perfect conspirary theory LOL So lets take a look on what is fake and what might be real but missing some vital clues. You can find several good Youtube channels created by people trying to build a working magnet motor. Some of them have no problems to admit failure and still keep trying and updating their projects. Did long enough and you see two outcomes. The first is giving up or "realising" that it will never work. The second often seems like a user is getting some relly good results and is really close to keep the magnetmotor running. Both disappear without and updates or traces. Now of course this is just confirmation that it will never work, but then again: What if it did already quite a few times? Even Tesla had patents for a magnetmotor and so far none of his patents were a hoax. Although none of his patents allow to actually build a working devices without some additional info and knowledge. And that is the key that I am trying to get: The lost knowledge.How can a magnetmotor never work? That one is quite simple from the start. If a linear model won't work no matter where you start then a rotary version will fail as well. And if a linear version works, it has to do so far at least 5 segments and with preferably increasing or at least constant speed. Having said that and assuming you know a little bit about magnetism: Ever wondered about shapes of magnets?? The common types are block, round like a bar and those disk like ones, some even with holes. A less well known version is the ring magnet. You can look them up as well as their corresponding magnetic field geometry - or what is assumed to be the right geometry. To give you a clue: All those floating spinning toys use a ring magnet in the base and onother one in the spinner. In the center is a dead zone for the magnetic field that is far lower than further out on the ring. And the strnger outer fields also reach further - giving the entire spinner a bowl like area to float on, the spinning just stabilises it like a gyroscope. A similar flat disk magnet wouldn't have this indentation in the field but rather a dome like sphere. The ring just kicks a dint into this sphere if you don't mind the simpification. Similar changes in the field structure happen when you combine two or more magnets. One example we all know is stacking identical smaller magnets. And often we are suprised how much stronger two thin disk magnets are compared to a single. Distance however sets a certain limit. And take those hook magnets... Just a small ring magnet in a metal pot with core. Remove the magnet and just by itself it is far weaker. Why? Quite simple.... The same way a transformer core directs the magnetic flow, the metal part of the hook magnet provides a shortcut for the magnetic field - and in return all is much stronger ;) Now you have some more clues, but still there are tons of options for failure... The most common is the sticking effect. No matter how well you planned and designed in most cases you linear or rotary prototype will stall sooner or later. Even if started manually at high speeds some seem to run very long but once they slow down and stop it is obvious they always stop where the magnetic field won't allow the binding effect to be overcome.Wouldn't dare to say that I have a working magnetmotor, but I might have some clues you want to try if you decide to give it a try yourself. So how COULD a magnetmotor actually work? Like in the Perendiv examples all over the web, you could aloow a moving responder to the rotor. Like a piston the responder will be lifted in areas it would otherwise limit or reduce the speed of the system. Well designed only a few mm would b required but it also means wasted energy to move the responder. Then there is the nice way of modifying fields by adding magnets in different angles and polarities. Lets say towards the end of your stages on the linear model it is hard to overcome the binding effect from the end of the previous stage. The perendiv model would now somehow change the distances. But you can also add magnets to lower the binding effect ;) Like a ring or hook magnet you can shape the field and offer a stronger repulsin field or a lower binding force. Last but certainly not least is the option of adding magnetic metals like iron or somehow weirder ones like bismuth. So, do we have any examples of something very common utilising any of this? We sure do :) Take a speaker apart and you end with the cage, the membrane, the actual work coil and the magnet. We don't need anything but the magnet so take a good and very close look. What in the audio world is called a shield to prevent the magnet from messing with things close by is exactly the same as on a hook magnet ;) Only difference is the tiny gap for the coil. The magnetic field is directed into two paths, one by the metal core, the other by the inner enclosure of the magnet or the magnet itself. The coil operates in the area of maximum flux.Last hints... If you take two identical and strong magnets with north or south facing up then it is quite hard to push them very close together. But check what happens if you try the same wen both soth poles (or both north poles) are placed on a magnetic surface - if in doubt your standard fridge door. Suddenly you can move much closer together with the same amout of force (not considering the added friction!). And similar story for opposing configurations. Where in free air or on a table the magnets would just jump together, on a metal plated you can move them much, much closer before this happens. Copper pipe and magnet fun :) Ideally you would have a straight copper pipe and a cylindrical magnet that has a loose fit in the pipe. Aluminium pipe work too or even a roll of aluminium foil if you have nothing else. A magnet in the pipe will travel very slow down the pipe, friction is not an issue here. So what is slowing it down? The magnet creates a field in the pipe and through that the pipe generates electicity. And funny enough this electricity creates an opposing magnetic field in the pipe - the magnet slows down. Even if you glue it onto a wooden stick it won't rush through it. Trying to push it by hand and you feel the created resistance. The faster you push, the harder it is to push! If you made it all the way down here with the reading then I have to assume you fit into one of three of my categories. a) You are a total sceptic and just read it for your amusement. If so, then please don't post a reply with usual negative feedback, instead see it as the same fun you had reading it ;) b) You are at least curious and like to play with magnets. In this case take the above as inspiration to explore more ways to have fun with your magnets! c) You are more or less frustated because you wasted a lot of time and some money to build a magnet motor that just won't work. A and B might go on and enjoy the fun, C however might want to read very attentive now ;) If you take some indicator sheet for magnetic fields, like these funny green ones, and play with moving magnets then you see a very interesting effect on the "screen". The otherwise static field lines change chape and sometimes even seem to disappear or shrink. With a small rotor assembly it almost looks like flashes when the magnets move past each other. This effect is often totally neglected and to be honest I overlooked it for a long time as well. Being able to see how the magnetic field changes gives the thing an whole new dimension so to speak. Creating a magnet with a complex shape is difficult to say the least. Only ferrite or ceramic ones can be used and you would cut of machine them according to your desired shape and with regards to the orginal center of the magnetic field. So most people revert to the classic way of shaping by adding magnets of various types, sizes and amounts. Modern neodymium magnets make this trial and error process easier as there are many sizes and strengths available. Add a detector shield of suitable size and you have hours of fun time ahead of you. But doing so in any rotary assembly is next to impossible. So what did Yildiz differently and what was missed so many times? Yildiz took it a step further and not only provided "shunts" to create very strong magnetic field from the generated electricity but also a second rotor. Since we all start small lets focus on the basics first. Remember the hook magnet and speaker or the copper pipe? Some examples for shape shifting your otherwise static magnetic fields: 1. A magnetic metal "connection" from one (low in the armature) pole to an opposing (high in the amature) pole with cause the field from the "high" pole to "bend" towards the connected magnet. 2. A magnet with an orientation of 90° to the last magnet is the sequence will severely influence the field of this last magnet! This goes for either orientations! 3. Adding a non-magnetic "shield" around a magnet, like a piece of copper pipe, will not affect the static field of the magnet. However it will severely alter the field of the enclosed magnet when another magnet passes it! It will also affect the overal field during the passing as the moving magnet will also induce a field in the copper by affecting the field of the enclosed magnet! Thickness and lenght of the shield influence the strength of these effects. 4. In a simple perendiv motor design the bar that creates the attraction for the spinning part is a magnet too. Either a long bar type or two small ones with an iron or nickel rod between them. There is no need for a piston or something that drives the bar up or out of the way ;) Just use the right magnet at the right spot on your rotor to repell the bar ;) Mount the ar with suitable springs and you suddenly can have multiple stages on your rotor instead of just the usual one! Don't forget the moving magnet on the opposing side of the segment in question though as otherwise you still will get stuck. (Hint: You can place a small but powerful magnet in the center of the opposing bar ;) Just make sure you limit the springs movement so the bar won't be pulled closer)Ok, hold on now! Does a magnet motor actually work or not? I can only give hints and say the laws of physics as we know them apply to magnetmotors the same way as everything else. Unlimeted motion without supplying energy is not possible. Limited motion with adding or using energy however is still possible and real. The same is true for being able to machine, 3D print or otherwise manufacture at very tight tolerence and accuracy levels. This includes bearings or bearing systems with very little friction losses. Just check these floting and rotating magnet toys that look like a spindle. Only a tiny needle like pin makes contact with a glass surface - next to no friction loss. A proper and supposedly working magnet motor should provide more energy than what it uses - one way or the other. No law of physics lets us get around the fact that such a motor could only keep spinning if the produced power or motion energy is at least the same as what is required to make it move. Magnets lose their strenght over time, they are like a very slowly depleting battery. So, isn't it funny that all magnet motors so far that claimed to work also had the requirement to replace the magnets once the things fails to work or start? And if you leave a very strong neodymium magnet shielded from outside fields or magnetic stuff than your grandkids will still find a quite strong magnet. Do a little performance test with your new magnets, like how much force is required is required to lift them off a steel plate. Make the same test with the magnets once you played around extensively with them in your motor. Now take a spare magnet that was never used from the orginal batch and compare both against each other ;) If the motor would not use energy then why are the magnets depleted to a certain degree, realted to runtime and usage time? Wait a minute! Does that now mean it actually works? Lets just say energy is certainly used. We only know similar effects from electromagnetic systems. But did anyone ever really check how much actual energy is in magnetic field generated by a non electric magnet? Get a good sized N52 neodymium magnet and check how much force is required to pull it off a steel surface. Now try to get the smallest sized electromagnet capable of that force and check how much energy it consumes at the level that equals the pulling force of the N52 magnet ;) Makes no sense to even try to compare these you will say now. I just say energy is energy and we were formed to only think in certain ways and don't even try silly things like this ;) To keep the fun up let us imagine we would actually have a similar energy available than what our electro magnet would require. In reality more because we wouldn't have electrical or flux related losses in the metal around the coil. Or is the imagined reality, no clue ;) If true it would mean even a motor with very bad efficiency would be able to create huge amounts of torque. Well, torque is basically acceleration. Which would mean our motor would not just be happy to spin, it would speed up until the bearing fail or the thing is ripped apart. Imagine a dental drill of that size and weight suddenly falling apart at full speed... Every example of motors claimed to be working, that are not fakes, seem to be happy no matter what the load is. It the thing turns a generator than it would have to slow down a bit with the increased load but they don't. With no limited factors otherwise this makes them a fake. Even a perfect motor would have to react to load changes.... Don't we agree that the stronger the magnetic force or field in a conductor the stronger the resulting magnetic and opposing field of the conductor? We use the difference to either drive a motor or take out electricity... But if you take the "open" shielding of a magnet in a changing field than the influence of the shield on the overall field gets stronger with stronger field changes. And properly desinged and orientated they would actually double as a natural limiter for the rotation speed. Once the electrical energy in the shield becomes too strong it will be able to cancel out the field of the enclosed magnet...If we assume a magnet motor is really possible and works with the intended output to keep it spinning or even take energy out: Then what would be possible downfalls that stop this thing happening in everyones garage? We can explore the stars but so far no one bothered to invent anything to visualise magnetic field in a 3 dimensional way other than by simulation. No realtime and true observation like this. The few working technologies that exist rely on sensors, interpretaion and filling in gaps. But imagine something like a detector shield as cloud! And then even better with selctive spacing to get a realtime view of where exactly the field lines go. All we can do is forget our teaching and try it out anyway ;) If by some mistake a magnet motor would really work right away, then chances are high the inventor would wonder why that thing takes off like mad and how to stop it. Unless well prepared it would certainly end in the destrution of the motor. But the inventor would know what to look for in the next prototype. The logical conclusion would be to the couple the energy taken to the speed while physically limittin the free load speed. The other one would be the design the electrical generator around the and within the motor. To even get close to this point you would have to spend endless days and nights working on finding a solution. The closer you get the more disappointment when the final model still fails to keep spinning for more than a few hours. Most people will then accept defeat and move on... Still not saying it actually works but if you made it to this point in time where it could be easier to move on and do other things:Ever wondered what would happen if you "shield" a magnet with a coil? Of course nothing would happen as we know. But try this in some fixed assembly that allows you move another magnet through the field of the shielded one. Perferably witha force gauge or some option to read out the energy required to move it through the various stages of the field. See what happens if you short the coil or add a resistor to it ;) Now if this coild is able to produce electricity then the more we use the more the effects on the required force would change. What do you think would happen if you combine common coil relations of electric motors to a "coil shielded" magnet motor? Right, all these coils would interact with the magnetic fields of the coils they are connected to... And through that with the overall field surrounding the enclosed magnet..... I leave up to you to imagine how these interacting coils could provide "resistance" or "acceleration"/"surplus electricity"...Like they say: You can only find out if you try ;) To keep up the positive thinking: A permanent magnet just sticks to any magnetic surface and does so with the same force. But the real energy loss in terms of getting weaker can almost be neglected. Any electromagnet capable of the same holding force woul require ongoing energy supplies to keep it up. It is using energy the same way the permanent magnet does! The difference is the permanent magnet is not seen as anything that would provide us with energy.... And if it can't provide energy other than passing through coils then why the heck does it keep sticking to the fridge year after year? It does require energy to keep this weight up doesn't it, even if you add a thin teflon disk and oil to reduce friction? ;) No magic, no "free energy" bogus, just plain physics viewed from a slightly different angle than what we learn in school ;) Have a good laugh and a good beer, then read it again and just consider some of the things here that are not mentioned in any literature about magnetism that we commonly use. Now I got you thinking, didn't I ? ;)

Topic by Downunder35m   |  last reply


Long Range Off the Grid WiFi Repeater

Hello Everyone,  I've got quite the project that I am undertaking and I am looking for a bit of advice. This will be my very 1st forray into long-distance wifi, as well as off-grid power resources, so Im biting off quite a bit at once! I have a friend who has been helping me with the research who has a much firmer understanding of both electricity and hardware, but he will be out of town for the next week and I would like to get a bit of progress on this while he is gone. SO, I shall consult the hive mind known as the internet. Alright, this project consists of creating an uplink between a remote shed, and a home in a nearby city, with a broadband connection. The rub, there is 10,000 ft mountain range in between the two. We have a site were we can put a repeater node at approx. 10,000 ft elevation, that has wonderful line-of-sight to both locations. However, this site is very remote, and will have to run off the grid obviously. The distances are as follows: Home to repeater: 3.96 miles (thats with Google Earth following the contours of the          mountain/valley, not sure how to make it just do a straight angled shot, so thats a rough estimate) Repeater to Remote shed: 2.68 miles (same issue) Background environment info: shed has generator + 60w solar array with 3-4 deep discharge lead RV batteries at 7400 feet. Has spring fed running water, which could be utilized for power as well, as obviously its always running. Repeater location is at 10k, as stated. Moderate to high winds very likely (data from peaks of similar altitude in the general area show gusts ranging from 40-60 mp/h, temperature ranges of  averaging 7 to 90+ for a the later part of July and August (F). Obviously, its very possible to get soemething below this, though the lowest Ive ever seen at the shed has been -15 (f), I would say most winters we could get a few nights that see temps below 0, but not often. Equipment Ideas: So to pull this off, we have come up with two ideas for the network equipment, which I shall discuss 1st, then I will show you what we have come up with for power.  - Network    - Repeater Node: rb433 wireless access point ($99.00) http://www.routerboard.com/pricelist.php?showProduct=43         with 2 r52h mini PCI wifi chips ($59.00 x2) http://www.routerboard.com/pricelist.php?showProduct=69         2 8-18 inch satelite dishs converted for long-range WIFI use (20.00 x2) http://www.engadget.com/2005/11/15/how-to-build-a-wifi-biquad-dish-antenna/ OR instead of a rb433, we could use 2 WRT54G Linksys routers like this. (I also have 2 BEF 801.11b routers that are legacy to the WRT54G. I would like to use this if possible! http://hackaday.com/2005/08/23/how-to-greyhat-wifi-repeater/ Now, I know that this later choice would increase power use by about double. From what I have been able to find, the WRT's would at anywhere from 4.2w to 8w of power. Anyways, I like this later choice because it would be significantly cheaper for the equipment, but do you have any other ideas? I know that the RB433 would work great, but its rather expensive all said and done after I throw up the power as well. Plus, if it takes a lighting strike, its out of commission, and 2 cheap linksys routers are much cheaper to replace! Anyways any input here would be great! - Power  so power to the repeater node is the real challenge. We crunched the numbers and came up with something almost exactly the same as below: From the datasheets, a routerboard will draw between 6-10W. So design for 10W. Over 24 hours you will need 10Wx24h = 240 Watt.Hours of power. For 7 days, you need 7x240Wh = 1680 Watt.Hours. A single, large deep cycle 110Ah 12V battery gives you about 1320 Watt.Hours of power, almost meeting the requirement. Now, to look at the solar panels: A good rule of thumb is to install 6 times the wattage that is drawn by the device. This is because only about 8 hours a day in sunny weather gives you maximum power output from a solar panel. So the other 16 hours you need to draw from the battery. (So already you need 3 times the wattage drawn by the device to break even each day) To generate 1 full day of extra battery power per sunny day, you need another 3 times the wattage. This is how we arrive at 6 times. 6 x 10W = 60W. So at a minimum I would recommend 60W of solar panels. That qoute comes from http://diywifilink.wordpress.com/ and http://mybroadband.co.za/vb/showthread.php?179547-Advice-needed-Setting-up-wifi-repeater-11km which is a project from a guy in South Africa almost exactly the same as the one that we are working on. The numbers came out to be about the same (Though they were a bit different when we calculated for the WRT54G option.) so, 60w of power generation to keep a decent charge on a battery. Now, we have a 60w panel at the shed, which is rather large to take up to 10,000 ft and place on the side of a mountain, and given the consistent wind element up there, we are hoping to do a hybrid system of both solar and wind. This is where things get tricky. A perfect balance, or even a more wind heavy balance would be great, such as 30-40w wind 20-30w solar. That keeps the panel size down, and uses a power source that runs 24/7. A Faroun Savonius wind turbine seems like the best system, but the controller to prevent overcharging etc is where I get nice and lost, having breached into very unknown territory. https://www.instructables.com/id/Faroun-Savonius-Wind-Turbine/ http://www.fieldlines.com/board/index.php/topic,129060.html This looked at 1st like a good, cheap system to use a controller board for the wind, but my question is would the controller board that comes with these solar panels (see below) work for both. That below is the setup that we use more or less at the shed, with some mods, such as a better alternator. http://www.costco.com/Browse/Product.aspx?Prodid=11298029&search;=solar&Mo;=5&cm;_re=1_en-_-Top_Left_Nav-_-Top_search⟨=en-US&Nr;=P_CatalogName:BC&Sp;=S&N;=4001192&whse;=BC&Dx;=mode+matchallpartial&Ntk;=Text_Search&Dr;=P_CatalogName:BC&Ne;=4000000&D;=solar&Ntt;=solar&No;=3&Ntx;=mode+matchallpartial&s;=1&topnav;=&Nty;=1&s;=1 So, can a small, 30-50w wind turbine and generator be built, with a small solar array to power this thing? I dont care if we have some down time, this is primarily going to be used as a system to get a weather station with web cam to send in hourly photos during the peak hours. I can have the system at the shed shutdown automatically  using some cron jobs in linux during the evening to conserve power. When there are people at the shed, we would like to be able to get a good enough wifi connection to use a wifi device (such as an android phone or ipod) to use as a voip phone in essential communication. The teenagers aren't going to be chatting with their friends for hours, but we would like to be able to put a short call through in case something goes wrong, or we just need to get ahold of someone at the shed or in the city. Next the equipment at the shed should be comparable to the repeater node,  sans 1 antenna and just some low power embedded system. We would like to get a webcam and weather station hooked up on this end, but that can wait for upgrades later if needed, if power doesnt allow it. like I said, a simple water turbine could be used (something similar to the wind turbine perhaps?) and even another wind turbine could be built to add extra power dedicated to running any system at the shed, though I dont think the wind is quite regular enough to be viable here, but if its cheap, we could throw it on anyways. equipment at the home in the city is simple, just use an extra laptop or desktop we have laying around to be server/router, hook up antenna to this, broadcast connection, run the weatherstation/webcam web server off of this. So, thats the plan, but load of input is needed to try to come up with this. We hope to try to keep this sub $1000.00, but the budget could go higher. This is DIY at its finest! Thanks in advance for you help!

Topic by kydan   |  last reply