Search for pulsating in Topics

flexible light rope or similar light moving device

Am searching for method to replace old or upgrade new idea for creating safe toy which allows child to operate from control box or reistat the movement of color lights through safe tubing- similar to light rope but changable through speed and direction. Mostly speed. Enough rope to shape into any form. thanks, west virginia kate

Topic by west virginia kate    |  last reply

how do i make an ac current with a battery? Answered

Hi, i have searched over the internet many a time, looking for how to make pulsating dc or an ac current, however all my results end up with devices which use ac or pulsating dc, which is comming from some homemade ac-dc converter running of mains. now, i am trying to find out how i can use a aa battery to aquire an ac current, or pulsating dc current, preferebly using parts aquirable from a disposale camera. the reason i need ac or pulsating dc is so that i can build a voltage multiplier, and also a tazer. i have tried plasmanas instructable on making a worlds smallest shocker, but it just doesnt work, if you cant get the specific transistors and transformers only aquirable from polaroid brand disposable cameras. plus there are no details on where to buy the parts, or even their details, beyond resistance and capacitance values. the main thing though is that i need to make the pulsating dc or ac from a portable power supply, aka a battery, as i also wish to make a dc-dc boost converter to use on different components within my rc tank. please help, whoever can answer my question best will receive a " best answer"

Question by oldmanbeefjerky    |  last reply

why is my 433MHz wireless receiver outputting a 6Hz pulsating output?

Hello, i recently bought this receiver and have tried it out with my 433MHz transmitter, and something strange happens. im using it to light up an led, and the led is flashing at what ive calculated is about 6Hz. why is it doing this? for some reason it ceases to do this when i hold the antenna of my transmitter within 2-3cm of where the antenna of the receiver should be (i havent added an antenna yet), and the frequency drops the further away the transmitter is, though not by much, maybe down as low as 4hz at 30M. could this have something to do with the fact that the frequency crystal says R315A? does this mean that its 315MHz and not 433MHz like my transmitter?, i wouldn't expect it to work though, and i did order it as 433MHz or could it be just the led? i have nothing else which i can use to tell otherwise. what i want the receiver board for is to power a relay. i haven't got the relay yet though. will this cause the relay to rapidly switch on and off? the transmitter i am using is a standard 4 channel 433Mhz transmitter (brown wood style plastic cover) standard with any wireless modules available on eBay and receiver transmitter combos on dinodirect. on both ebay and dinodirect, none of the sellers have a clue about where the datasheet for this is, or how they work (i doubt at dinodirect they even know what it is).

Question by oldmanbeefjerky    |  last reply

Pulsated DC Chopper with Inductive load

Components USED1. MOSFET ( 47N60C3 )2. Primary Transformer Coil3. 12V. 2A Switching Power Supply4.function generator ( currently using 66kHz frequency)5.oscilloscope6. Schottky Diode ( PMEG100V060ELPD )The required output is mentioned with the circuit diagram. I changed the magnitude of function generator gate signal but that was the best I could to remove the oscillatory part of output?2. how to get full 12v across the Inductor coil?3.any other possible ways to achieve the above mentioned required waveform across the inductor coil?Extra components Available,extra 2 of 12v,2A power supply

Topic by m.a.dasunumayanga    |  last reply

Flashing/Pulsating 10mm Red LED voltage

I just finally got the throbbing/flashing/pulsating LED, but a 9v battery doesn't seem to be cutting it. I bought the 10mm LED from Radioshack here. I was just wondering how high I could go in terms of power. I was thinking about a 10v DC, and go to a 12v. But I don't want to blow the LED. I was also wondering how I can get the LED to flash slowly, like it was "breathing". I started off with a 1000µf 16v capacitor, then went down to 470µf 25v capacitor, with no significant change. I also have a 470ohm resistor that I got with my 100 pack of white LEDs. Any recommendations would be appreciated.

Question by Lazarus65  

rubber inside Pulsation damper on toyota fuel rail

Hi i have a toyota pick up thats leaking fuel from the pulsation damper on the front of the fuel rail ive found pictures of what this thing looks like inside just a spring and a round piece of rubber sandwhich between round pieces of metal ..i am trying figure out what type of rubber that is maybe tire rubber or rubber gloves  maybe  someone here has rebuilt one  hope you guys can help 

Topic by Lauriepaul  

Pulse charging to constant flow

So i had to replace the chargercable on our babycall and used a female usb port. The adapter uses 6 volts to charge the device but if i wanted to use a 5v portable charger, how can i make the current flow instead of pulsating? Capacitor? And what value?

Question by josvol81    |  last reply

How do I make a set of say 4 incandescent bulbs pulsate in brightness?

I would like to make a display where incandessant bulbs throb like they are being powered by a varying vlotage. The bulbs would be 75 watt or 25 watt depending on what I end up doing. I am even considering some 30 watt edison type bulbs. How do I make a controller for something like this?

Question by spacehead    |  last reply

in what way we can convert dc voltage from battery into pulsating ac signal? Answered

Actually i am a beginner in doing mini projects. my projects is to increase the range of ir rays emitted by ir transmitter and i have  heard that it can  be done if we give ac signal as input than dc signal 

Question by sandiri    |  last reply

I want to make a led art, that everytime a button is pressed it sounds like a heart and blinks a red led with it?

The puslating led I can manage with a 555, but don´t know how to make the sound part. The smaller the better. Yeah I know I´m noob at this, but thanks for any help?

Question by w0rm5    |  last reply

Removing rust from the inside of a motorcycle gas tank using the electrolysis method? Answered

Which is better for removing rust from the inside of a motorcycle gas tank using the electrolysis method? Steel anode or carbon graphite anode? I have tried both. I like the carbon graphite better. It seems to be a cleaner process and to work just as good as the steel anode. Should I use 12 volts or 3 volts? Does a pulsating DC work better than a continuous DC? What is the best amperage?

Question by Goldwingracer    |  last reply

Can someone make me some code for an arduino?

I need the code to make a white LED pulsate, reaching the peak every one second, and and the other way around. I need it for a night light i am making with an ARDUINO duemilanove. If someone wants to be really helpful, write me some code like this, only the throbbing starts at 10 at night and stops at 6 in the morning. Then i can make a throbbing apple logo to put on my door to show that i am sleeping! :-)

Question by thenewdoctorwho    |  last reply

How to control DC motor off and on cycles. Answered

I need to control the speed at which a pager motor is on or off. I don't need to control the motor speed, just the timing of off and on. What would be the easiest way to accomplish this? (I have some 555 timers and an Arduino Uno so either of these would be preferred methods). I've tried but failed with the 555 timer and a pot to do this.  Eventually I would like to have two pager motors cycling between off and on (pulsating effect). Thank you, -shortdiesel

Question by shortdiesel    |  last reply

Help with a sun jar idea? Answered

 So recently I saw the 'ible on here about how to make a sun jar, which I think is really awesome, and I want to make one now... The question I have though, is if anybody knows how to make a circuit, without programming that will make the light raise and lower in intensity, so basically, it has a very slow pulsate but it never turns off and doesn't go super dark either... I have been trying to address this problem myself for some time, but haven't come up with a clever solution yet. --Thanks!!

Question by arhodes18    |  last reply

I need a high voltage, high amperage power supply

I am in need of a power supply that can give out about 500V @ 13A. I know it's high, but I want it to charge a capacitor(400V, 1000μF, 13A) for my coilgun. I've already tried a flyback charger, but the result was to blow the capacitor up(I think that it couldn't withstand so much voltage, despite the amperege was lower that its threshold). I don't want that to happen again and I want a relatively fast way to charge the capacitor. Also, the power supply needs to be portable. Another thing: the voltage is not mandatory to be THAT high; the amperage also(let's say...1 or 2 amps...)... However I need DC pulsating current, at 20 kHz NOTE: I really hope that I'm not asking too much.......

Question by N3v3rm0r3    |  last reply

how can i find out which part of my charger is malfunctioning? Answered

Hello, I am desperate for help. I have a PWR+ charger for my laptop I purchased a few months ago, today it stopped working. What happened? well the charger still has some function, when I checked it with my voltmeter the output varied from 3 to 6 volts, the little LED on the charger was pulsating, not rapidly, but in short 1 second intervals. Could this be a problem with the voltage regulator? The required amount of power that a normal charger for my laptop outputs is a steady 14 volts, not sure about the current. Now my charger is useless and I don't want to spend another 30 bucks to get a new one, please help. Thanks in advance.

Question by nahum45    |  last reply

An Alarm Clock Idea - No Lights, No Sound

I'm a pretty deep sleeper, and I don't wake up very fast in the mornings, which is bad since I ride the school bus to school. I set my alarm clock, with a high volume, but it still doesn't wake me very good. I've thought of trying to make an alarm that flashes a strobe light, something like a deaf person might use, but didn't think it would work very good. So, my idea now is to think of a way to make an alarm clock that gives pulsating shocks when it goes off. I have absolutely (well, 99%) no idea how to connect it up, nor how to produce the shocks. I'm thinking a shock with high voltage, but low current, like static electricity. I figure that should wake me. Do y'all have any ideas, or better suggestions? Also, do you think that the shocks (if usable) would cause any dangerous effects on my health? Thanks!

Topic by Bran    |  last reply

How to power a 5v circuit with batteries? And will my circuit always draw power?

I'm building a fridge door sensor that will beep when the door is opened. The one that is on my fridge right now is very inaccurate and so I want to improve it. So what I've done is make a sensor that is mounted onto the door to makes a contact when its closed. When it's opened, I'm using an ATtiny 25 to wait 30 seconds and then make a pulsating buzzing noise through a buzzer. The ATtiny operates in a range of 2.7 - 5.5v and I want to power it with batteries. I'm new to electronics so I don't know much about powering stuff with batteries. My questions are: How do I get that power that I need? Will the batteries get drained quickly because of the circuit design? (power always going through the contacts) Also: Does anyone know exactly how to hook up a battery to an ATtiny? I think that the positive should go through my switches and then into vcc, but I'm not sure where to put the negative. Thank you so much!

Question by yohiyoyo    |  last reply

Heartbeat Pulse+Speaker+555 timer

Hello all! I'm posting this idea that I have for making my wife a gift for our anniversary. I'm posting this in burning questions as my research time for this is rather limited as the whole project is to be a surprise. Here's what I aim to build... What I want to make is rather simple, I want to make a pulsating heartbeat sound through either a piezo speaker or just a small 2 inch or smaller speaker. The more compact the better as I plan to integrate this into the other half of my project. The problem is im not very familiar with the 555 timer, I normally don't use them in my projects as I try to work with AC most of the time. But that's another topic. So anyways, my idea is to set the duty cycle low so it's 3 quick pulses and then about a second of silence. I imagine programming in Arduino would be easier but therein lies the problem: I do not know how to program and every Arduino I have is fried. (I make good use out of my components!) This is when I turn to the community and sincerely ask for your help in making this possible. Someone who is more familiar and can quickly and conveniently answer this is obviously more then welcome! This is where I plan on getting most of my research done in my off time. Any help is greatly appreciated. If further explanation is needed please do not hesitate to ask. :-)

Topic by 49percentGood    |  last reply

Years Back in the 80's a friend had a stereo from "Fingerhut" that had spinning l.e.d fans that reacted to the music? Answered

The stereo had two fan like l.e.d. arrays of about 10 each in different colors red green yellow that were on fan like structures inside each of the 12" woofers on his home stereo that he got from "Fingerhut" the l.e.d.s would pulse with the music one side of a blade to the bass and the other with the highs usually ending up making a red & green with yellow pulsating orb inside each speaker that was seen through the black speaker cloth, I have never seen anything like this before or after anywhere but it was a very nice display and could be made with wheels or ceiling fans or any fan I bet, I wish I would have taken electronics in high school instead of CAD but the cad system was cutting edge in 86 and our school had access to them...the only thing I have seen like this is the floating message thingys that use a back and forth l.e.d.s waving in the air. I know if someone builds it it would sell good even for the automotive speaker markets...this was cheap chines junk it could not have cost much to build it but it did look great!!!! I have seen the automotive led wheels that can display pictures and such but this is way simpler than that and the power source and electronics were not spinning withe the leds... trust me build it and you will spend hours watching them while listening to music almost as good as what music videos used to be :) Anybody Seen or Know where they can be bought or can build them? Fast Ed88

Question by FastEd88    |  last reply

How do I make Electroluminescent Fabric respond to sound?

Hey guys,  Been planning out a little project to do in my spare time that I'm hoping to have completed by Halloween this year (lot's of time for trial and error). I'm planning on making a set of Tron Legacy suits with some slight modifications. I've gone through all the tutorials regarding this particular project on Instructables and I'm mixing and matching methodologies and stuff. It's just this one thing that I'm trying to figure out that I really need help on. Everything is still in the planning phase so I'm pretty open to any suggestions on how to go about the whole design. Now, I've gotten that people use Electroluminescent wire/tape/strips for most of these projects. M friend and I are planning on importing some EL Fabric for our purposes.  What's going to be different about our projects is that I'm planning on making some of the EL patterns on the suit sound reactive. I had built a couple of speakers in the past that I want to incorporate into the design. Probably going to mount them on the back and disguise them as Disc holders. The idea is to have the speakers play some music which the entire suit is supposed to light up and pulsate to. My problem is that I'm importing some EL Fabrics that are not sound reactive and I'm not to sure as to how to modify them to be so. Furthermore, my friend who's making this with me, wants the lights to go off in sequence or according to some pattern. Basically, she wants us to be walking light shows, something which I am at a complete loss at how to accomplish. Can anyone point me in the right direction as to how to go about this exactly? The essential thing here is getting the lights from the EL fabrics to go off according to the sound playing in some organized aesthetic pattern.  Thanks in advance, guys.

Question by wedged_mind    |  last reply

How I had a computer turn on automatically when the BIOS did not support It

So, I just got a Kindle and want to automate the downloading of news feeds to it. I wanted a PC to turn on when I woke up in the morning, download the feeds, transfer them to my Kindle, then shut off. First problem: The spare PC I put together for this does not support automatic startup in the BIOS, and neither do any of the other motherboards I had. So, I thought of a way to use an alarm clock to turn it on. When the alarm clock would go off, it had a speaker that would produce a tone. This means it was switching power to the speaker on and off very quickly. This would not drive a relay directly, so I made a "filtering" circuit consisting of a few transistors and a capacitor. When the clock goes off, it charges the capacitor with a transistor. This buffers the on's and off's into a kind of pulsating DC current into the cap. The capacitor drains into another transistor, turning it on. This activates two relays at once. One presses the button to turn off the alarm, and the other turns on the computer. Since the alarm was turned off just a moment ago, the speaker does not sound again and it does not turn the computer back off. In the first picture, you see two sets of black and white wires going into the PC. One comes from the relay to short the power switch momentarily, and the other goes to the +5VSB on the power supply. This line provides +5v at low currents, even when the computer is off. The 5v powers the buffering circuit. That was the difficult part and took about 4 hours. Everything else was easy. When you get a Kindle, Amazon gives you a free email address you can use to send files to it. I installed Calibre (an awesome free e-book manager) on the PC and had it run on startup. I set it up to download the feeds then email them to the Kindle through WiFi. Turning the computer back off was easy as well. All you need to do it make a shortcut to "shutdown.exe -f -s -t x" and add it to the startup folder. The .exe is the Windows shutdown program. -f force-closes any open programs, -s specifies a shutdown (instead of restart, logout, etc) and -t x is how much time it will wait before shutting down, in seconds. I set it to a half-hour. So, now I can have my news feeds on my Kindle before I leave for school. :D Funny thing is, the whole alarm clock bit could have been avoided if I wasn't too lazy to just press the power switch when I woke up in the morning! XD

Topic by 1up    |  last reply

nerf ranges

(NO MODDED NERF GUNS)ok i was wondring what are ALL of the ranges of nerf guns lleave a comment of its lowest range and its highest rangeand what gun it isBuzz Bee:Big BlastDouble ShotLaser Tek Mega Missle Mustang Six Rapid Fire RifleSingle Tek Tek FourTek Six Tek Ten Lanard Blasters:First Shot Big Salvo Blast Bazooka Maxshot Over and Under Sonic Bazooka Speed Loader Triple Shot ERTL BlastersPump Action Shotgun Rapid Fire Pump Action Shotgun Nerf Blasters:Airtech 1000 Airtech 2000 Airtech 3000 Airtech 4000Airtech Jet SquadronArmor Shot ArrowstormArrowstrikeAuto GripBig Bad BowBlastfire Bow N' Arrow BuzzawChainblazerCommlink IICrossbow CrossfireDart Tag BlasterDefender T-3 Disc Shot Double CrossbowEagle EyeEliminatorExpand-a-BlastFireflyGatorHidden ShotHornet Hydro BazookaIron Raptor Laser Fang Lightnin' Blitz Lock N' Load Longshot Longshot Front Gun Mad HornetMagstrike Manta Ray Maverick MonoblastNB-1Nite Finder: min:16' 7" max:23' 4" (thanks to zack scott from you tube)Nitro Quad Pen Blaster Powerclip PulsatorRapid Fire 20Ratchet Blast RattlerRazorbeastRazor Fin Reactor Recon Rip Chord Courtesy of DraconisRoto Track Sawtooth Scout Secret Shot 1 Secret Shot 2 Secret Strike Pocket Blaster Sharpshooter 1 Sharpshooter 2 SlingshotSneakshot Spiderman Dart Tag Gun Splitfire Stinger Stinging Scarab StrongArm SuperMaxx 250 SuperMaxx 500 SuperMaxx 750 SuperMaxx 1000 SuperMaxx 1500 (New) SuperMaxx 1500 (Old) Supermaxx 2000SuperMaxx 3000 (Blue) SuperMaxx 3000 (Green) SuperMaxx 5000 Switch Shot Switch Shots MaxSwitch Shots Super Switch Shots Ultra Tech Target Titan Triple Strike Triple TorchVulcan Warthog Whiptail Scorpion Wildfire Promotional Blasters:Kung Fu Panda Commander CrossbowPirates of the Carribean Flint Lock BlasterSpiderman 3 Blaster Spiderman Wrist BlasterStar Wars Rebel Trooper BlasterThe Batman Light Signal BlasterThe Two Towers of Uruk Urukai Bow Wayne Tech Tri-Fire Blaster Other Blasters:Air BazookaAirzone 8 Shooter Air Zone Arrow StormAir Zone Dual Fire Dart BlasterAirzone Scorpian Bow Halo Ma5c Rifle Kids Stuff Bow n' Arrow Kilroy Magnum PistolLightstorm 2 Optimus Prime Blaster Periscope BlasterPistol Splat PS-800Pool Blaster Roto RocketSplatmatic Thundersplat Spy Gear Signal Launcher Star Wars Clone Troopers Blaster SuperSoaker MaxD2000 Super Soaker 50 20th Anniversary EditionThe Proffesional Trigger FireUSB Missle Launcher Vortex Firestorm Vortex TornadoXxl BazookaXxl Skeet ShooterBlast HammerElectric EelJust Toys CrossbowMarshmallow ShooterMissile StormPreceptorQuick StrikeRam RodRocket StormUltrox Quadra CannonWrist Blitzerthanks for helping! =)

Topic by knexsuperbuilderfreak    |  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

"Sonic" drilling or cutting

If we look up sonic drills today we usually get some fancy machines driving pipes in the ground, preferably softer ground.But the term includes all types of machines that use sonic vibrations to advance through a media.With the ancient and claimed to have never existed technologies in mind I did some digging...In the food industry vibrating knifes are quite common, same for "air knifes" on softer food.Even in the meat industry they find more and more uses now.Ultrasonic cutting or welding is the same thing and included in "sonic".Same for some experimental sub sonic drilling methods currently being tested.The general idea might be as old as using vibrating equippment to compact stuff, like concrete, bricks and so on.What you can compact by vibration you can also make "fluid" by vibration.Industrial feeder systems utilise this to the extreme by even making light and fine particles like flour move like water without causing any dusting.What all the techniques have in common that a suitable tool or tool head is used and that it is attempted to use the most suitable vibration frequency for the job.Anyone operating an ultrasonic welder knows the pain of finetuning for a new electrode or just new part to be welded.What does that tell us now that makes the understanding easier?Take a bottle of ketchup, preferably one that is still quite full.Turn it upside down and noothing comes out.Shake it a bit and you are either lucky or drowned in red.But hold it at an angle and start tapping it and the red sauce flows out easily.What it true for most newtonian fluids is in some way also true for non-newtonian fluids.Ever mixed corn starch and water to make these funny experiments with it?Hit it hard and it reacts really hard and is not sticky at all.Leave your hand resting on it and in sinks in and sticks to it.Stirring it very slowly is easy, go faster and you get stuck.You can do similar things with by using an external source for vibrations.For example a vibration speaker mounted to a smal cup of the goo.If you place sand on a sloped piece of plastic or sheet metal then at a low angle it will pile up easy and stay.Start vibrating the plate and the sand will start to flow off.Works fine with a vibration source mounted to a piece of steel bar or rod and a bucket of sand too.Trying to press it into the sand requires a lot of force, especially once you are a bit deeper.Let it vibrate properly and it slides rights down.If we can do the simple stuff as well as really complicated stuff in the industry then what about other materials?So far we use vibrations to make things move out of the way, compact things, transport them or to heat them up for welding plus some cutting applications.Considering the variety one might wonder why no one tries it for "difficult" materials.Machined surface can be found throughout ancient history.Finding "machined things" were vibrations was clearly used is a bit harder.The great walls are not a perfect example here as the views differ quite a bit on how they could have been created.But if we leave things melting them or a secret concret like recipe for creating for example granite then vibrations start to make some sense.You find some interesting videos on youtube where people use speakers, wires and rocks to confirm you can actually "machine" them by vibrations.Especially granite has some quite musical properties, big boulders as well as smaller ones produce destinct sounds when you hit them hard.Tests and measurements were made on granite and other hard rocks to check how fast sound travels in them , how it is refeclted and where the sound comes out or affects the surface the most.Lets just say every sample gave different results.Shape, density and dimensions affect not just the resonant frequency but also where and how the sound travels in the rock.What if??We can use a simple speaker, a plate and some rice to see how patterns form under various frequencies.Works with sand or other granules as well.The interesting patterns are the so called harmoncis.Here we see clear and destinct patters, sometimes with extremely fine lines and areas of softly vibrating granules.Some people say these harmonic frequencies have all special meanings and uses.We mainly used them to avoid problems.Imagine your new TV would not have a housing tested to be stable with all frequencies the speakers can produce.All of a sudden your back of the TV might start to rattle ;)Same for car engines.Harmonic vibrations are eliminated wherever possible.Otherwise they could multiply and affect other things in the engine or around it.Simply put it means we have various options to detect and measure vibrations on a surface or in a system.Back in the day every half decent backup generator had a mechanical indicator for the frequency of the supplied electricity.A set of tiny forks with the desired on painted red and several on either side of it.These forks were designed to get into harmonic and therfor quite intense vibrations at their set frequency.If the one for 50Hz looked blurry then all was good ;)The same principle god be applied on a big boulder of granite.Place the "vibration meter" at the desired spot and start moving around the vibration source on the surface until you find a spot that causes maximum response on the meter.Best thing here is that if you then place that surface area onto another peice of fixed in place granite both pieces will start to loose substance if vibrations are applied.The fine sediment forming is then usable as an indicator where to move the vibration source to continue once the effect literally wears off.Is it feasable?Well, if we trust mainstream science then the answer is no.A huge amount of vibration energy would be required for such a hard material, despite ancient proof that says otherwise.Semi industrial test also seemed to confirm the theory as only with very high amplitudes (loudness) and while automatically adjusting for the resonant frequency changes a measurable amount of material was removed.I struggle a bit with that as for the testing tool heads made from hardened steel or carbide were used.And that with little or no regards on how the head and tool itself affects the output.I mean in terms of having the max possible movement happening right t the tool contact surface!There is a huge difference between applying a vibration to a tool and using a system, tool and tool head DESIGNED to work at the desired frequency!Otherwise we wouldn't need a computer to design and test a horn for welding purposes or shade a knife spefically so that the vibration go along the right axis and in the right direction.You not break a hard thing with a very soft thing unless it travels fast enough to become harder as the target!This complicated explanation basically just confirms that if you hit water at a too high speed then it will just break you into pieces instead of offering a soft splashPlease do not jump of bridges or such to confirm this yourself!!If that is really true and science says it is, then how about the other way around?Works fine too, or we wouldn't have pressure washers or water cutters.Now for the part where I hope some really smart people leave helpful comments:If we can cut steel with just a stream of water, then I ask:Isn't for example copper much harder than water?Steel is much harder than copper but water cuts through it.The answer here it simple or complicated, depending on how you want to expain how it works.Comes down to speed and pressure plus the right nozzle shape to prevent a beam expansion.But then water is indeed "harder than steel".Questions:Lets say we would use a copper pipe that in lenght, thickness, hardness and diameter is optimised to transmit a frequency so the pipe end sees the max vibration like a feed horn for ultrasonic welding.Not to hard to calculate these days :)Now imagine said "main frequency" would be optimised for the pipe but also be a harmonic frequency of the rock to be worked on.The pipe end would deform quickly, abrasion does the rest and it fails before even making a decent sratch that is not copper metal on granite.No matter how hard we press nothing good enough will ever happen.BUT: If we would add more hormainc frequencies to feed our pipe we can multiply the amplitude quite easy!Just try with a sound generator from your app store, needs 2 or more channels to be usable.Pick for example 400hZ on one and 800Hz on another, then finetune around these number to hear how the tone changes ;)My theory goes like this:If all "working frequencies" would just harmonics of the resonant frequency of the granite, then they can be tuned so the effect on the pipe end is minimised.The overlaying frequencies however should result in the same effect a water cutter has: The pipe becomes ultra hard.The better the match and the more you have to get it right the harder the pipe will be.Adding now a "drilling frequency" or multiple could be used to drive these harmonics slightly out of phase.Like with the sound generator on your phone we end up with a pulsating sound, or vibration.While the pipe still vibrates at the same "hardening" mix the drilling frequency creates a peak like a jackhammer.Try it by using the heaphone output on a small speaker and placing some light and tiny things into the cone.The will violently jump around during these pulsing tones.For a drilling system the output can be mechanically maximised by utilising a pitchfork design.A head holds the vibration speakers and the tynes are tuned good enough to the frequency of the speakers.Always two would have to operate in sync though as otherwise the pitchfork movement that transfers the sound down the center bar won't work.This head could then be desgined to act as a holder for a quick change of work out pipes that are no longer long enough for tuning.I guesstimate that a well tuned design would result in a copper pipe being able to drill at least 10 to 15cm into solid granite before it wears off too much.And we are talking here about just a few mm to get the thing out of tune!But would dare to desing such a thing just to confirm a theory that no one ever really dared to test? ;)And if friction welding works as good as ultrasonic welding, then what would happen if we try this with the right frequencies and vibrations instead of wasting tons of energy?

Topic by Downunder35m