ring my bell?

I have a switch and when it is opened I want to activate a bell for a second or two. I don’t want the bell to go off again until after the switch has closed and opened again.  What would be a good solution to this?  I’m guessing some kind of relay board but not sure where to look for this.  My bell is 120vac and switch is low voltage DC.

Question by wannab1   |  last reply


dash and marker light problems?

My dash and marker lights are having intermediate problems and im wondering if i can bi pas the relay and wire it strait to the switch.  it is a 1991 Subaru legacy?

Question by abadfart   |  last reply


My actuator died after just 2 months. Was the relay the villain?

I set up a linear actuator on a timer with a relay and 12 Volt 5 Amp battery exactly like to project you show on your site. It worked like a champ for about 2 months the stopped. I thought maybe the battery need a recharge but that wasn't the issue. When the switch opens and remains open the red light on top of the relay remains on. I keep the door open for about 4 hours in the morning then it closes. It opens again for about 4 hours before dusk then closes again until the next morning. My concern is that the red light on the relay is indicating that the switch is on continuously sending electricity to the actuator. After 2 months it just fried the actuator.  I took apart the actuator and it looks like its brand new with no black spots on the copper wires. I'm hoping I just have a bad actuator.

Question by Joenjmortgage    |  last reply


I need a 50volt 30amp 12v coil relay? can i use a 120volt ac and just put dc through the contact?

Hi all, sorry if this is already a dead subject but I was unable to find my answer in any other Post. I am making a controller for a slot car track. I will be switching individual tracks on and off. The problem is the track voltage and amperage. I have looked everywhere to find a relay that can handle 50 Vdc and 30 A. The coil I need to be 12 Vdc at the lowest amperage possible. Can I use a 120V ac relay and put  50v DC across the contact with no problem? Again the coil would be 12v dc so no problem there. Any  and all help is much appreciated.

Question by Jacob753c   |  last reply


Countdown Timer

Hey guys, first forum post. I have just gotten into the electronics field, and I have made a few circuits that I have read schematics from. There's something I want to make, and it's a countdown timer. This is want I want it to have: Be able to count down from at least 15 seconds and be able to change the amount of time Have some 7 segment displays Use the least amount of voltage possible (ie: not need to use the mains or some 12 volt power supply, id rather use a couple of AA's) Have a relay capable of turning on or off a light. And to be as simple as possible. Because I am rather new to this I would rather a schematic, rather than just some help on which components I need to use, because I don't know where they need to solder to where.  Thanks

Topic by ryanlg   |  last reply


could i use a split charge relay to controll charge to batteries from a wind generator?

Hi. i am making a wind generator for my home. i have made the generator but need a charge controller for the batteries. i would make one but i have no idea how to and can't find any useful schematics. then today i thought. what if i used a split charge relay? i could connect the turbine to the alternator connections, connect my battery bank to the car battery connections and a dummy load like a water heater or something to the leisure battery output. what do you think? yay or nay? thought i'd ask first in case it will ruin an expensive battery bank. thanks in advance :) 

Question by ljarrald   |  last reply


please how can i make simple ir alarm that dial from mobile ?

Hi please i need to make a simple circuit  that contains ir on/off switch , that will dial pre saved nimber on the mobile , for ex. , i can connect the botton (1) of the key pad in the mobile on some relay , win the alarm on it will dial the saved number simplly , the IR will be sender and recevier , when some one or something cross the red line " the IR reays " , the circuit will be just a ON /OFF switch to run a relay the relay will connect the dial up on the mobile device key bad can any one help me with that ?   Thank you all !

Question by wa7aa   |  last reply


Extemely simple automatic emergency light.

I'd like some help to settle an argument regarding my extemely simple automatic emergency light.According to my friend, who installs emergency lighting, this circuit is too simple and has too many components missing but I say he's wrong, if one part fails it can easily be replaced. I'm not and electronics expert either.I'll explain the circuit...5v comes from a 5v 2A phone charger. Battery is a 32Ah 12v SLA. 12v charger is a smart charger with built-in status monitor.SPDT 5v relay rated to switch 12v @ 17amp maxThe light is a 12v 5 metre LED Strip with built in current-limiters and draws arount 2A.Basically, 5v powers the relay which means the battery is connected to the smart charger that keeps it topped up while there is mains power (240v here in UK). If there is a power cut the relay turns off and battery is switches over to the LED light Strip. Its that simple.It works as designed, no parts have failed and I haven't found any signs of over-heating. My friend believes it should all be one circuit and not seperate parts and is a fire risk as it is.He just won't let it go, so does he have a point or is he just being a/an _________ (fill in the blank, lol)? I've included a schematic of the circuit. Not sure if I've drawn the relay properly though.

Topic by cyberraxx   |  last reply


How do I wire a 12V DC motor to micro switches, relay digital timer and battery?

I am wanting to wire up a door to my hen house that will open in the AM and close in the PM. I have a 12V DC powered cordless drill motor and a digital timer. Can you help me on what I need to make this all work as far as switches, relay, etc. and possibly give me some guidance on how to wire it up? Just so you know, I have very limited electrical experience. Thank you. Rod

Question by dobecool   |  last reply


Protecting my new power supply

I've got a 12vdc 500ma power supply that I'm using to trigger a few solid state relays. I'm also using the same power supply to provide input current to a little micro PLC (Automation Direct DL05). Both the relays and the PLC have a wide range of acceptable input voltages and their current requirements are about 15ma per channel at 12 volts. The count is 6 relays and 8 PLC inputs, if all are on thats about 210ma. I once killed a similar power supply by allowing the leads to touch and short-out. I would like to protect this power supply from the same fate by protecting it from short circuit. I thought about attaching a reisistor to the end of one lead and covering all but the outlet of the resistor with heat shrink tubing... problem is, it would have to be a big, bulky power resistor to handle the wattage. Is there a simple component available that will limit the current upon short circuit that I can place in series with my loads to protect the power supply? As I said, it doesn't have to be precise and it doesn't matter if it jerks the voltage around a little.

Topic by fluoronator   |  last reply


Tool-activated shopvac for dust collection? A relay for activating a shopvac for dust collection when a tool is started

Some expensive shopvacs can be "tool activated", meaning that the shopvac hose can be attached to the dust port of chop saw, sander, router table, etc, and the shopvac turned on or energized when a relay device detects that the attached tool is drawing power.  It saves trips between the shopvac and the tool, making automatic dust collection at the point of dust generation more practical. Off the shelf solutions are $50 to $80, usually consisting of a short extension cord with two outlet sockets.  A power draw on one outlet energizes the other.  The theory is simple enough that I can't think of a good excuse for why it couldn't be done with stock components.  

Question by joel.will   |  last reply


Is anything a "must save" off a junked electric stove? Answered

Replacing my old coiltop electric range (might be repairable, but I'd rather put the money into something I'll like better).  The old one's just going to be hauled away. A friend has requested the oven racks, and the new range comes with its own power cord, so the 220V cord is of dubious value and likely to just take up space... is there anything else that might actually be worth the effort of removing? (I suppose I could save the control panel and see if I can get its relays set up to control something else, but that requires figuring out what voltage it actually requires and I'm not sure it's worth the effort. Especially since the controls are what failed. Probably just a stuck relay, but...)

Question by orksecurity   |  last reply


first time instructable publish would like review and suggestions for improving next

Just published first instructable on 4/20/13 and i would like review and constructive comments for further publishes.  not sure when it will be on site. title is heated handlebar grips under motorcycle.  thank you. and i hope this first one looks and relays info properly.

Topic by maguyver   |  last reply


Hamster's heating pad

The winter is on it way. I'm having a hamster, a winter white, but the last winter his caught cold and it cost very much for him to cure him. I don't want my hamster to be sicked any more, so I made a heating pad for him. I used this instructable  https://www.instructables.com/id/DIY-heated-clothing/ and I found it is very well. I use a two - meter 26 - gauge wire, and it only result in a 0.15 ohm resistance. With an 1.5 v voltage, It work well and i need a 10a fuse to protect this circuits:) But last week it overheated and my hamster was burned, quite bad. I'm wondering if there is a solution to this. Would you mind giving me a circuit in which: - there is a thermistor to sense the temperature. - If the temperature is to high (30 celcius degrees ), it gives a relay some voltage and the relay breaks the heater circuits. - And it component should be popular, cause I'm a kid and don't have many time go round n' round to find them. Me and my hamster will very appreciate your kindness. Thanks all.

Topic by vietanisme   |  last reply


Automate Astronomy Dome - Help

I am interested in building an electronic system to control the orientation of an astronomy dome based on the orientation of the telescope. I need suggestions on the various components I might use. Motivation: This is a Meade 16" LX200 telescope in an Ash Dome. Owned by a friend who doesn't use it much. I get to use it, maintain it, enhance it for about 1 week a year. I can control the scope with my laptop using a program like "The Sky". However, after the telescope is pointed, I have to manually manage the dome and rotate it with a bi-directional switch. Very tedious. The motor is 1/4 HP, 1725RPM, drawing 5.6 Amps at 120VAC. There are programs that can be used with the telescope control to manage the rotation of the dome, but I am thinking of a lower-tech solution. I would like to put some reflecting tape (perhaps mirrors) on the sides of the dome slot and point some lights (perhaps LED lasers) with a pickup device (hence the idea of the garage door styled "electronic eye"). The general idea would be to set up some simple device that would detect the change in location of the direction that the telescope is pointing, and activate the dome to track with the telescope. If the telescope turns, the light would no longer be reflected and the dome would try to "find" itself or re-orient to a point where the light is once again detected by the reflection from the mirrors on the dome. I was thinking about: Garage door electronic eye activators 120V 6A relay switches 2 enhancements: detect direction of the telescope; bar codes in the reflective tape wireless signals to send activation to relay switches (telescopes go in circles and eliminating wires is always good.) Anyone have any ideas about pre-built components, sources of good relays, electronic eyes, etc? TIA, Chris.

Topic by chrisjx   |  last reply


Help requested for purchase of components

Hi. I'm a newbie to embedding but I have a project that needs this and there is no commercially available solution that I can find so I need to learn how to build it myself. This can and will be done in modules... I figure I can tackle one task at a time until I end up with a complete working system, but use the system in the meant time, as I get it completed. The main goal is for an electric motorcycle conversion dashboard,  which will include a password protected relay switch "ignition key" to power the vehicle on securely (Task #1), a user configurable display to show speedometer, odometer, tripometer, clock, battery pack voltage, motor rpm/temp, controller temp, coolant temp, etc via a waterproof rugged tablet (probably a Windows 10 tablet, probably with an Android emulator installed). I'm finding that there are so many different options available, I don't know what to purchase. I want to spend my hard earned money wisely and just buy what I need the first time. Instead of learning the "hard" way, I want to learn the "smart" way. Please help me get started. Thank you in advance!

Topic by Stevonator   |  last reply


How can I make lights that turn on when I open my shed door?

I've just put together a shed for my motorbike that will soon have electricity wired to it. I want to make a lighting system that turns on the lights when I open the door and turns them off when I close them. I don't want to spend a load of money so was thinking relays and microswitches. Any thoughts or opinions would be great! Thanks Jack

Question by sladek   |  last reply


How build a cost-effective device that automatically clears exhaust fumes out my garage?

Soon I'm going to move into a building which shares living quarters with a garage. I'd like to rig up some sort of relay-triggering device that opens a nicely sealed set of vents (one intake, one output) and activates a fan exhausting garage air  - one that activates the minute I open the garage door, and then continues exhausting fumes for a few minutes after I drive the car away (and close the garage door). After those couple of minutes, the fan would stop, and the vents seal shut Due to the "lay of the land" (garage right off a busy road, with very short hidden driveway) I will be backing the car in, so exhaust gases will be concentrated at the back of the garage (close to living areas) - rather than near the open garage door. And as my car has a turbocharger, I often need to let it idle for a minute or two ( to let the turbo cool down) before turning it off to park. So it would be most useful to be expelling those exhaust fumes out of the garage! The question is - what's really the most simple and cost-effective platform for this kind of a system? Could a 555 timer, a few discrete components and some relays do the job elegantly? Or am I better off just diving into Arduino-Land?? Any related ideas (solenoid-closed vents, efficient fans, ducting through walls, etc ) that are especially thrifty - would also be greatly appreciated!!!

Question by rockandroller   |  last reply


Novelty Car Horn - Help!

I bought an Ooga horn, and a button wiring kit, but i'm having some trouble...First off, there's no relay, should there be? Also, do i need to buy an additional toggle switch? I don't want to replace my existing horn, simply add another horn. Do I need a new fuse, too? And...I don't really understand the diagram, so if anybody knows where to find better instructions, or can provide them, that would be greatly appreciated.Key to the diagram:1: Original Horn2: Existing Fuse3: Horn switch on steering wheel4: Fuse 10 Amp5: Selector SwitchMy HornThanks!

Topic by Weissensteinburg   |  last reply


Looking for a circuit- proximity switch ?

I am building a fiberglass car and I do not want to have any door handles. In otherwords, this will be a very smooth body. I am looking for a circuit to make a proximity swith that has 2  elements in it. When I  pass my hand over one of the plates it latches power to the second sensor and  when I pass my hand over it it causes a solenoid to open my door. One of my students made a similar device for me a few years back and it got destroyed by mice in my car..  I will be using isolation relays with 1 amp draw to operate the door solenoid at 12 v. Any ideas?I already have 2 3x4 inch metal plates fiberglassed into the body for antenna.

Question by gurobuzz   |  last reply


50cc Chinese scooter problems? Answered

I have a 2001 Chinese scooter, 50cc, and it has some problems... We took the handlebars off to fit it in a vehicle for transport (Yeah, stupid idea, I know now...), and now, the wiring is all messed up. First off, the electric start won't work anymore, I'm going to go through, and check a relay and the battery voltage tomorrow. Second, when I kick start it, and yes, It'll kick start, but only after 50 some kicks.. But when I kick start it, the engine starts going full throttle, but the throttle is not twisted at all. Throttle cable problem? Lastly, the turn signals are messed up a bit. The right blinker flashes one of the headlights inside of the blinker.... What the hell? All the wires are connected correctly. Please help!! Thanks!

Question by Zem   |  last reply


Home automation & Home door sequrity including one android apk file project available ???

Please help me for this project. how will be arduino program code , which pin are connect to apparatus to apparatus. please give me all description step by step this project implimentation. Project planning:-                   1.Home automation & Home door sequrity including one android apk file.                   2. 4 Relay:   1. Blue led light.                                 2. Red  led light.                                 3. White led light for bath room using PIR sensor.(this light switch on/off only using pir sensor,                                            because-wet hand electric shock on switch or, damged mobile display).                                 4. Fan using voltage regulator.                                  note:- light switch on/off & fan switch & voltage regulataor incease/decrease including appk file.                   3.Home squrity switch board on/off may be   a.display board on wall of house.                                                                b. display in android apk file.                   4.when open door with corect srquirty,then photo upload in memory card.if incorect password then a lout of sound.                   5.when fire in house ,alarm using gas sensor. Room temperature, huminity show in display. Apparatues:            A: Led light on/off by mobile app.                  1.ESP8266 Serial Wi-Fi Wireless Transceiver Module for IOT.                  2.Generic(unbranded )4-channel relay control board module with optocoupler, 4 way relay module for arduino                  3.Arduino Uno R3 ATmega328P ATMEGA16U2 Compatible with USB Cable.                     or,xcluma Atmel Atmega 2560 Mega2560-16Au (16 Mhz) R3 Board+Usb Cable For Arduino.                  4.Led light 3(Blue,Red,White for Bath room),Motor Fan.                  5.REES52 REES_2 Bread Board or Solderless Pieces Circuit Test Board Project Board.                  6.Jumper Wires Male to Male, male to female, female to female.                  7.Generic KG001 HC-SR501 PIR Sensor Pyroelectric Infrared Module 2pcs(for bath room & door open).                  8.Adraxx LM7805 7508 Positive Voltage Regulator IC, 5V 1A.                  9.Resister 1k ohm.                  10.REES52 MQ2 Arduino Compatible Gas Sensor, Methane, Butane, LPG, Smoke Sensor.           B: Home sequrity.                  1.Quantum QHM495LM 25MP Web Camera.                  2.SanDisk Ultra MicroSDHC 32GB UHS-I Class 10 Memory Card With Adapter.                  3.REES52 621033926893 Universial 16 Key Switch Keypad Keyboard Fit for Arduino by REES52.                  4.Silicon Technolabs 20x4 Line LCD Display With Blue backlight HD44780 for ALL Arduino,Rasp Pi,AVR,ARM,8051 (Blue). Software:      1. Arduino-1.8.5.                2. wampserver & notepad++ (for php web page).                3. Android Apk file.      please help me for this project. how will be arduino program code , which pin are connect to apparatus to apparatus. please give me all description step by step this project implimentation.  i will waiting for you.

Question by somnathpanjaproject2018   |  last reply


How do I start a Pajero jeep with Low compression ?

I bought a pajero sport 2007 2.5 a few months ago that always had trouble starting. I would heat it 4 times then crank and she would pick up with a puff of smoke then run fine. No problem starting when warm. Having ruled out the plugs (replaced) the relay (12 volts) a local garage man did a compression test and told me that two of the cylinders had low compression We were going to run some oil additive through it to see if that would help But now the B**ch wont start at all. it cranks fine but wont pick up. Its outside the house and I am waiting for the mechanic to get time to do a house call. I was wondering if there is any sure fire way of starting it up with slightly low compression so that I can run some  oil additive through it  or if I get it started what is the best treatment to put through it. also If I have to open up the engine how complicated and expensive would it be I have a mechanic friend coming to stay with me in a few weeks what are the minimum tools needed?

Question by Cargorm   |  last reply


Is this the right way to wire an old, one capacitor washing machine motor ?

I actually have an old Brandt 556T washing machine, and I'm trying to replace the internal mechanical program with an arduino some electronics. Actually I'm trying to directly run the motor at it's both speeds, and both directions. So, the motor is a Selni V689, and I also have another motor laying around. It's a Selni V604. The two of them seems to be using the same wiring. So, for the moment I'm using the older one (the V604) to experiment. After some googling, I understood this kind of motor uses a single capacitor to select the direction of the rotor, and it enables the motor to start without help. We can  wire it without the capacitor, and spin it manually to start it, or use the capacitor to start it properly. So, I ended up with the schema linked here. It seems to be working, except for the old V604 which, in second speed, runs faster in one direction that the other... But for the V689, it seems to be okay. I need to ensure that my wiring schema is really ok, then I'll try to use as few relays as possible to be able to fully control this motor with 3.3/5V logic. If anyone can help me confirm that, I'll really appreciate it ! Thank you guys ! NB: I firstly thought there was a problem with the power consumpsion of those motors, but I was wrong, it's fine.

Question by etienne51   |  last reply


Solar deathray smelting? Answered

So Im not sure of the capabilities of the fresnal lens in terms of maximum temperature but I've seen them melt brass. I was thinking with a solar death ray on top and a charcoal fire on bottom that I could get temperatures to melt steel. I have drawn a rough sketch of the overall Idea I really need someone to further refine this idea into a working schematic that I can create when I do I'll document it all and relay the results on here to help others recreate it. Now This setup will be behind my greenhouse on the corner of my property on the side that would be hidden from the sun, however if the base pivots on an axel I'm thinking of using, then it will be able to catch the sun from all the points when it's most useful. In that I'll also have the fresnal lens on a pivot bar to help get it on my focusing lens which will be a plastic and water style parabolic lens my only concern is that if I can't turn that lens will it hinder my project entirely or will it be fine, plus I'm not sure about focal point on this kind of lens. On the sides of the frame I'll build for the fresnal lens I'll have strings attached for turning on the bar and I'll be able to lock it in place to keep from fires around my smelter.. Hopefully! Overall dimensions may appear small in the drawing but the fresnal lens should be at about I'm guessing at roughly 25 feet off the ground, or roughly 7.5 meters and the focal point in the middle will be found and adjusted to the fresnal in terms of height. I think it was roughly 1 meter so I'm not sure entirely I would love some feed back on this idea as I plan to make a smelter with it to complete my in progress foundry I'm building in my shed.

Question by Kaelidian   |  last reply


Getting more power from a quartz clock movement

Using a transistor to boost the output from a quartz clock to drive a larger motor in steps. Is the idea sound what would I need? Having read a couple of instructables on equitorial drives, I found myself wondering why you couldn't just use a quartz clock movement to drive one? They don't produce much torque is the answer to that one. Why not? I took one appart to find out. The gear chain is very flimsy moulded polyethylene, or maybe nylon. the power comes from a tiny armature that makes 1 turn a second in 2 pulses the magnetic pulses are provided by a little cuircit board with the quartz ossilator on it. Here endeth my actual knowledge. My knowledge of electronics is minimal give me a good set of instructions and I can build it (unless its a joule thief but thats a different matter) but don't ask me how it works. My limited understanding of a transistor is if you put a small current or voltage across 2 pins you can get a bigger current or voltage to flow across one of them and the third, something like a relay. I was thinking if I took the out put from the quartz cuircuit that provides the magnetic pulses and used it to trigger a transistor to pulse a higher voltage and current through a small 3 pole motor kicking it around 1 pole per pulse. The motor I have a salvaged and rebuilt in an earlier instructable runs on 3V and draws 0.2A when not under load. the largest motor I have to hand is a big 7 pole one designed to power model planes or cars draws up to 15A on 7.2V the timer cuircuit for that one needed 3 Mosfet's in parralle so I'm guessing thats not possible.

Topic by Stan1y 


Device Worn on Tongue Allows the Blind to See

For the past 10 years researchers at the University of Wisconsin have been working on making a device that delivers censorial input to the tongue via a matrix of electrodes worn inside the mouth. Using a camera, a computer, and the input device, individuals who have been blind their whole lives are now able to use this relatively simple and non-invasive device to see basic images. Applications for this technology range far and wide, not to mention all the awesome ideas for Instructables that come to mind. More info from the research page...What we have developed is a generic and flexible way to communicate information to people using an array or matrix of small electric stimulators on the surface of the tongue. In much the same way that people can use their fingertips to read Braille letters, which are patterns of raised dots embossed onto a sheet of paper, people can recognize simple spatial patterns using comfortable electrical stimulation of the tongue. For example, we published a preliminary study about two years ago showing that volunteer experimental test subjects could identify very simple geometric patterns such as circles, squares, and triangles. They identified these figures as accurately on the tongue as on the fingertips. And that's when we became excited about the possibilities for a tongue-based electrotactile display, electrotactile being the technical term for electrical stimulation of the sense of touch.The electrical stimulus on the tongue feels like a tingle or vibration; some users have said it feels like soda bubbles. The sensation is well-controlled and not painful unless the user deliberately turns up the level too high. Occasionally it will produce weak metallic taste sensations, a minor side effect. We have never observed any kind of tissue irritation with the gold-plated electrodes.1. One of the applications which has been commercialized is providing vestibular or balance information for people with balance disorders. This is a simple form of sensory substitution, in which the tongue is used to present information from an artificial balance sensor.2. Another application is providing directional or navigational information for people who operate under central command and control scenarios, such as military and civilian rescue personnel. Providing information via the tongue allows them to fully use their vision and hearing to respond to unforeseen threats or hazards. We have shown in the laboratory that it is possible to navigate a virtual maze (like a simple video game) using only information received on the tongue (i.e., buzz on right side of tongue means turn right, etc.).3. A third, more ambitious application would be providing very crude visual information through the tongue for persons who are completely blind. Our colleague Eliana Sampaio at the Louis Pasteur University in Strasbourg, France has used our tongue stimulator with a small video camera and demonstrated an equivalent visual acuity of about 20-to-830, which is very poor vision, but possibly useful for certain limited activities with enough practice. Wicab, Inc continues to improve this technology with the aim of commercializing it.4. A fourth application would be providing tactile feedback to the human operators of robots used forhttps://www.instructables.com/edit/new?type=forumTopic various tasks. For example, UW professor Nicola Ferrier is developing a robot controlled by the tongue of persons with quadriplegia which could incorporate touch sensors into its gripper, relaying the touch information back to the user's tongue.This summary taken from Synopsis of Tongue Display Technology 1/3/2008. Lots more information on the research page.More info on the general process of electrotactile stimulation here. (I can't believe that I am actually linking to How Stuff Works for this, but hey, there isn't an Instructable written for everything...yet.)

Topic by noahw   |  last reply


Very old shielding materials and techniques for permanent magnets and resulting possibilities

Forromagnetic meterials are not just called that for no reason.It comes from ferrous - iron.Iron has the highest permeability at normal temperatures.That means a magnet is attracted to it very strongly.We utilise this for transformer cores, the stuff inside a relay and the moving latch of the relay itself.Like current from an electrical system magnetic fields like to take the easiest route possible.Air is a very bad medium, so any iron close by will be prefered even if it is at a slight distance.You can check with a magnet, a steel bar and some iron shavings - please cover the are with plate first ;)Slightly less known is the option to also guide and extend the magnetic field this way.If you check how far the magnetic field of a magnet reaches and note that distance,then you can add some steel bars or rods at the poles - the field will extend through the metal.The most powerful example of this are the shielded magnets used for hooks or speakers.Except for a tiny area the entire magnetic flux goes through the metal.So in this lefover area the magnetic flux density will my many times greater than what the magnet alone would be able to.What most people don't know is that magnets also interact with other magnets in terms of their fields changing and distorting.The Halbach Array is a good example of this.Seen as a single magnet the array would have one weak and one strong side instead of even strenght for both.Wherever magnetic fields change a conductor can produce electricity or current.This in return causes an electromagnetic field that opposes the one from the magnets.Just drop a magnet through a copper or aluminium pipe ;)Since these distortions are widely unknow to the hobby tinkerer mistakes can happen ;)In the early days of exploring science some people already knew about shielding.And they also knew that certain metals have certain properties.Where it is quite hard to create a good coil from steel wire, copper works fine as it is not magnetic.What would then a copper shielding do?If you have two moving magnets with only a tiny gap then the resulting field distortions are quite huge.A copper shield around the magnet like a pipe would then react to these changes and also create a megnetic field that works in relation to the enclosed magnet.In simple terms it means the shield would let the magnet appear weaker or stronger depending on the field change.A quite old document I found gave some hints on how people thought in different directions back then.It was in regards to the design of a magnet motor by the way.Here various magnets were shielded in tube made of a copper-bismuth-alumium alloy.These tubes were then electrically connected so it created a single loop conductor.The claim was that the resulting electromagnetic field of this ring would drive the fields of the enclosed magnets sideways out of alignment.Like bending straight pastic tubes sideways.This "pulsating" would always happen when the magnetic binding forces reach max and so basically drastically weaken this binding effect.Another document talks about a "magnetised brass rod".A holes of the rod diameter is drilled through a block magnet.Not from north to south but through the middle where the flux is greatest.The claim here was that if that rod rotates fast enough a very low voltage with a very high current will be generated.Sounds easy and interesting enough that I might have to test one myself one day.The best one however is what I consider a hoax or being as good as Starlite.Someone back in 1908 claimed to have created a material the reflects magnetic fields.In lame man's terms it would be like an insulator around some electrical wire.The claim and some pics showed it, was that no magnetic field can pass the material.Or to be correct only a tiny fraction of what would be possible through air.A small magnet inside a longer tube of this material would create almost the same attraction to steel at the tubes ends as on the magnet itself.Measurements showed the field strength would be almost equal to a long mangnet of the same field strength.Imagine guiding the field of a big and powerful magnet through a tube around some corners or other magnets and then end in just a tiny hole for the entire flux...Too bad he never shared his secret formula to anyone knows to mankind.Isolation...Imagine you have an array of changing magnetic fields and quite strong magnets.Then you might face the problem that your focus on the "working" end neglected the other end of the magnet (stack).Providing some iron core material will keep thes field lines contained and away from interfering with your setup ;)But it also allows to use te otherwise unused end of your magnets more directly.For example by guiding to another magnet to affect its field strenght ;)Placing a sheet or steel between two magnets in a setup provides a "shared pole" so to say.If you have a north and south pole on a rotor at a distance of 5mm then a sheet of steel between will drastically weaken the strenght and reach of this combined field.It is like pulling the arch between the magnets down to make it more flat.And at and an angle the resulting field will also be slightly angled ;)Capping...When I first encounter this many years ago I couldn't really make sense of it.Quite complex..If you check the magnetic field lines with iron filings or similar then you notice how they go in a rounded manner from pole to pole.This is because the single field lines are of equal polarity and will dirve apart like opposing magnets.By capping the ends of a magnet you provide a short.Instead of diverting out like mad they will follow the cap and create very intersting magnetic field in return.If both poles are capped it is like pressing the magnet flat but without having a field on top of the oles - only aorund the center part.For this the thickness much must match what is required for the flux density.As a rule of thumb: if the end is still very magnetic then it is not enough material tickness ;)Interacting fields in a tube...This one is quite old too and seemed to have found no usable inventions apart from simple magnetic spring replacement systems.But it gave me some clues about Tesla "earthquake machine" ;)If you place a magnet in a tube and at it's ends magnets with opposing fields to the one inside then you can fix this magnet in place.Push one magnet deeper and the distance from the inner magnet to the other end will shrink the same amount.In this old paper two coils were around the pipe with the inner magnet between them.In this gap and at about the same width as the magnets length another coil was placed.Violent shaking would then create electrical energy at much higher level then modern shaker torches.In return an AC current on the outer coils would cause the inner magnet to move back and forth to create electricity in the center coil.According to the paper possible uses include: core less transformer, measuring minute changes in AC voltages, providing free power from a running motor...The last one had me stumbled for a very long time.Until I considered a different configuration.The whole thing is basically a linear DC motor - with correct timing of course.And in some motors we use permanent magnets.I am starting to wonder what would happen if we would design a rotor magnet like this?The running motor would be subject to constant field changes that affect the rotor.And a normal motor is always "even".By using four magnets instead of one we can push the field really flat.This means the area where the coil would operate (about 1/5 of the magnets area) will have a much stronger field.The resulting torque should be higher by about 25% !!Even a simple two coil model setup should show a significant increase in performance here.Timing is critical here but I tried some calculations based on 8 poles and the required "on times" for the coils.In a standard motor configuration with a single rotor magnet the coil is active for about 12° of the rotation.With a 4 magnet configuration this "on time" can be reduced to under 8° of the rotation to get the same amount of torque.An energy reduction of about 4% if you neglect losses and only think in time.If you think in terms like impulse energy then we are talking of about 15% !Shorter on time but still much higher flux density overall than for the long standard timings.Going the long run now:If you check how most DC motors work then you realise soon that for most one rule seems to followed.Only use one coild pair at a time.This is quite contradictive if you consider the geometry and options.A dual commutator would allow to use a second coil pair with a field OPPOSING the magnets instead of being attracted to it.After all: on you bike you pedal with both legs and not just one...And if you do it professionally then yu do the same as I suggested for the motor - you use the up pull of your legs as well.Doing it brushless only requires amodified h-bridge desing to drive the second coil pair at the right timing.Some will now say that it requires twice the energy, I say that for the same motor size your get twice the torque!Just imagine what that means in possible weight reduction for a motor - or its size to deliver the same torque at the same power levels when a normal motor is used ;)The more poles the more complicate the precise timing but no big deal really with modern electronics.Can it be improved even further?I though long and hard about that one until I considered EMF.A DC motor produces a lot of it when the elecromagnetic field collapses in the the coils.We do not utilise this energy...There is a tiny delay until the released energy levels are at max.My theory is that it should be possible to divert this energy into another coil set.If that coil is not the next active but still within a strong enough field area then the EMF would actually add to the drive of the motor.Only downside is that according to my calculations at least 16 poles would be required to get an optimum result.Way above of what I can create in my little garage :(In theory it should then be possible to reach about 98% efficiency for the motor....

Topic by Downunder35m   |  last reply


Printer disconnecting or USB port disappearing in Windows

First I thought to make an Instructable out of it but realised there are too many different printer models out there, so this time no images. What is this about you might wonder? Well, let me tell you my story first and you might see similarities to your problem. It all started with me getting a new PC as the old one got memory problems (RAM modules failed). After a few successful prints I noticed errors coming up in the log window. Mainly things like communication problems and that some data is sent again. Realised that on my new PC I did not check the speed settings for the COM ports, so I adjusted them to match the printer board and moved on without even bothering to check the logs. Then, half way through a bigger print, it all stopped and I could not even connect to the printer anymore. After a power cycle on the printer all was fine again but the error kept coming back every now and then. At this point I started to read up on the problem and the most common recommendation is to print over SD - too bad if your printer does not support it and too bad it does not address the issue at all! A few more technical answers pointed to the Logitech drivers, especially mouse, keyboard and 3D vision. As I was using the same outer hardware as before and also the same drivers (and same version numbers) I simply ruled this one out too, although it might be a vital clue for others. When starting to get frustrated and after opening a cold blonde I remembered that I had a similar issue a long time ago and that it was related to loose wires on the screw terminals for the power connection. Measured it all but according to my trusty multimeter all was fine. Now comes the fun part: I friend of mine with a HiFi fetisch was here when I testing the connection and he started laughing at my attempts. He explained that ALL his connections, no matter if power or audio signal are oversized! Here I started to wonder if he is up to something and looked up similar circuit board mounted power plugs. To my surprise they are all rated for anything between 1 and 5Amps. Even without a heated bed powered by the printer board I think everyone will agree that a max 5A connections is not enough. My frined then offered to check the plug and connector at his place - what a great thing to have friends :) He used a signal generator and small speaker with the plug as a connector between them. With an oscilloscope connected to both input and speaker you could see, while moving the plug, that the audio signal become somehow unclean - there where spikes and missing bits everywhere depending which way you wobble the plug. After taking the whole thing apart the destructive way we saw the cause: overheated contact areas with discolored surfaces. I replaced the plug now with a 250V/20A one from an old laser printer and had no USB or connection issues ever since. Ok, what's the thing with power and USB problems on a 3D printer? Almost all printer boards have the ground connections bridged to avoid interference on the USB signals. This mean, in case of a faulty power connection or one that is "dirty", the USB port on the computer can receive back EMF signal or even a voltage spike. In return a smart bios either disconnects the port or disables it until the problem is solved, in our case by restarting / reconnecting the printer. But even with no obvious signs of power problems you can get  a so called "dirty" connection. Dirty covers all from corrosion, worn springs for battery compartments, overheating or in the old days burnt relay contacts. For our printer it usually means that either the soldering connection on the board or a screw came loose, in rare cases like mine an undersized connector can burn out due to being unable to handle the currents. The bad thing is that you can not always spot these problems the easy way... Is there an easy way to tell that my USB problem is caused by a faulty power connection? Yes and no. Some boards offer indicating LED's, you connect power and the LED stays on even if the printer is disconnected from the PC. If it is more than just a Power on" indicator" this LED will be off after the printer stops working and in the device manager your serial port for the printer is gone. You might also hear the warning sound from Windows in regards to a device being disconnected. If all the above is true than most likely your power connection has a problem somewhere - if in doubt replace all screw and plug connectors for the power. Sometimes the problem is less obvious. Your print software might show communication problems in the log window or re-send a lot of commands. If the speed selection for the com port is the same as for the firmware of the printer board and as set in the printer software, it could also be a power connection problem. But to be on the save side try a shielded cable with ferrite cores on both ends first for the connection between computer and printer. Can I take any measures to prevent the problem? Sure, you could solder everything and make sure the wires are fixed in place so they won't move. But a simple indicator might be enough: Solder a piece of LED strip to the power connection on the circuit board - if the connection has trouble the LED's will show it in most cases by changing light levels or flickering. On top they act as a nice light to see what's happening during a print.

Topic by Downunder35m 


The Newman Motor Challenge !

I was recently approached by someone claiming the old Newman Motor wouldn't be good for anything.Well, I was a little bit offended by this as I already had my little toy version of it as kid.At that time though it really was just a toy for me.Critics still say the Newman Motor is nothing more than some interesting machine.And even the biggest followers will admit it is not a free energy machine, just a very efficient one.I experimented with, what some call fringe science, now for about 30 years.And it all started with math and my interest in unusual ways of dealing with problems.So what's behind the challenge?The original design was suprisingly simple as you can see in the above Wiki link.Just a spinning magnet in a (split) coil.What you don't find anywhere though is real details on the how to.Sure, you need to have some sort of contact linked to the rotation and timing is critical but what does it all do?You can build a drt simple model in a few hours with stuff you might have around already.Quite a few Youtubers are happy to share their creations.The actual challenge is to come up with what Newman really did inside his drum.And also why I think it is not the full potential his machine had.Build a simple Newman motor and check for how long you can let it run on a charge super capacitor.Then sit back and read some of the other magnet stuff I wrote.After that come up with a better design ;)I started to create some 3D models that need testing once I find more free time - should take some leave one day..But for those with little patience and an interest in the Newman Motor I decided to share my current idea:For some it might be really confusing although they know motors and magnetic fields.Those just playing with magnets might have it easier for once as they can pretend they followed my thoughts ;)The original design used two coils and a rotating magnet.If you consider how the magnet creates an electromagntic field in the coils then you have to wonder right away how it can spin.And most designs will indeed need a push start to get going!You can't have electricity produced without the magnet spinning and you can't make it spin without electricity!The current from the battery or capacitor can only flow at the short moment of contact on the axle.This moment needs to be timed "mechanical" as we don't want to waste any power on not required electronics.If you ever bothered to check the timing of a Newman Motor then you realised the collapsing electromagnetic field at the moment of contact actually is in reverse to what the manget has in that position.Unlike any normal motor it means the magnet produces most of the power the coil needs to make the rotor spin!So far for the well known facts, now for my fiction:I would like to call my version the Aussie Newman Motor as all things downunder are just different ;)Here are my current desing mods, that I freely share so everyone can benefit form many years of experimenting to save a lot of time.1. Instead of two coils a not-really-bifilar coil is centered on the axle.The coil is created like two stacked relay coild that have no bobbin and a "dint" to allow the axle to pass through.Without the big gap of the original less of the magnetic field strenght is lost and the coil is far closer to a homogenous magnet.2. The timing done by salvaging a simple DC motor's contacts and brushes.This allows for far higher currents and if the salvaged motor had enough poles also for a very short "burst".3. The axle contact is made with a cleaned steel bearing.After cleaning very conductive copper based lubricant is used in tiny amounts to prevent corrosion and provide a lower resistance.The clear benefit is that with the new timing system a lot more current can flow.Initial tests with a mock up model showed an increase in run time from the capacitor of about 15% already.With proper bearings and a salvaged DC motor I hope to reach 18 to 20% more than the original design.Now why the DC motor if a reed contact or hall effect sensor would be even faster and with less resistence?Neither can handle really high currents without additional electronics ;)Plus of course I wanted to leave the door open for the Aussie Newman Motor 2020.You might now say "Why bother if the above improvements are already so great?".If you followed my elsewhere for a while then you know the Newman Motor is only 2D but I prefer 3D or more harmony if you like.Right now the imagination of people re-inventing Newman's machine is limited.They try to get on the horse from behind - literally.Fancy electronics, machined parts and so on.But they never go 3D ;)You got it? :)There is only two coils!!The magnet rotates, same as the contact on the axle.One set of coils for each contact the salvaged DC motor has.Each set aligend to the corresponding contact.And now you will ask "How do you plan to connect that to a single DC power source?Well, that is why it will be the 2020 model - my time for tinkering is sadly limited because I still need to work to support myself.But if you consider that the original as a good model can run for over 10 minutes on a supercapcitor then ask yourself how long it could run on 4 or even 8 coil sets.And although there is no such thing as "free energy": There will be still space for more coils.Or other coils to just provide electricity that does not power the motor.Critics will now see their chance and state that if we add a load to these additional coils then this will cause a strain on the system.Of course they are correct here.If, however, the load is mechanical then the motor needs to supply basically the same additional energy.Plus all mechanical losses.The question is: How much mechanical load can we add before the motor is down to the same efficiency of a very efficient DC motor? ;)And what if our Aussie Newman 2020 would actually violate the laws of physics?We can calculate how much electrical energy would be required so a given motor produces a fixed amount of torque.Or we can just measure it, the beauty of science...We can do the same in reverse of course.Let's say a mechanical pump would require 500RPM and 100Nm of torque to pump 100 liters per minute.Then we could calculate what sized motor we need to drive the thing and how much power the motor would need.So again: What if the Aussie Newman 2020 would require far less than what science makes us think and still does this job on a simple 12V lead acid batty of 4Ah?Just saying... ;)I hope to have a presentable and working 2 coil system by May, so stay tuned!In case you are faster or even beter then of course feel free to show off your results or to post a link to your Instructable so everyone can verify it.

Topic by Downunder35m   |  last reply