Inductor coils?

How would one go about determining the milihenries value of an inductor coil pulled from an amplifier, well different ones I have found. And living up to it's standards, google has found me no information but what an inductor coil is and it's function, but no information on how to find inductance rating.

Posted by Punkguyta 9 years ago

Double-Opposite Coil Speaker Design?

So I finished a new speaker I designed, today. It was just then that I thought about the possibility of creating a new design. In the tradition speaker, a coil sits below the magnets, and they are pulled in and out of the coil, creating vibrations (subwoofer).I like this method, and all, but I wanted a bit more! So I got to brainstorming. If you were to put a coil around the magnets, it would still work - it's just have no bass what-so-ever. Well, what if we were to put a coil on the bottom, as usual, but add a second coil on the opposite side, while allowing it to encircle the magnets, but not get in the way. So when the magnets get pulled into the coil, the second coil does not interfere, but still is close enough to the magnets as to create sound. Would this have any adverse effects? Would it ever work? I've included an image so you can see my vision. I may very well just be stupid, but hey, it's an idea. Going to work on it tonight.

Posted by freethetech 6 years ago

how can i hook a keyboard to a solid state tesla coil?

I want to build a solid state tesla coil and hook a keyboard up to it. how can i do this?

Asked by rebel01 8 years ago

Heat pad

Has anyone made a Heat pad before?  I want to build one for an out door cat house.  Maybe I can just use a battery operated light bulb at a high Watt.

Posted by cnelson17 5 years ago

Opposing coil speakers?

Today's speakers have large heavy magnets, but what would be the result of setting up two coils which create opposing fields, one being the typical voice coil, the other being a replacement for the magnet.  Why isn't this in use today, is the power needed to create the required field just too great? This method could be used to increase volume while not overloading the voice coil right?

Asked by seedorfj 3 years ago

Can someone please make 3 bifilar coils?

Hello everyone I'm in the need for some BIFILAR COILS, and just to be detailed I don't mean the PANCAKE type. I will pay through PayPal or credit please comment to answer question no private messages why am I asking instead of making my own? I'm living in a tiny room do to my spinal cord injury. So it's a bit difficult at this time alsl lastly if anyone happens to have some they're not using or are done with a donation would be nice, I'd cover shipping and handling of course. Lastly if anyone knows where they're sold online please do say so, I've had no luck finding premades online. THANK YOU TO ALL AN ANY WHO HELP

Asked by bettersweeps 6 months ago

best schematic for a solid state tesla coil? Answered

Can anybody please help me with a sstc schematic? I'm thinking of building a sstc for an exhibition in my school and so i might need to run it for quiet a long time(like for a day with 5min intervals), and so it shouldn't overheat and die. Though I've found some designs especially the steve ward's sstc schematic, the problem is I couldn't get the ucc37322 & ucc37321 gate driver ICs, a suitable and more available substitute would be fine(I live in India). And which mosfet should i use for this purpose, i would be running it at 220v straight from the mains(in a H-bridge confg). And is the following audio modulator going to work with this?

Asked by jasshopper 4 years ago

Alternative Cooling design idea – Southeast moderate to high humidity

I need some serious feedback!  I have an 1896 Victorian, about 3800 sq.ft. but we did it right. Foamed the walls, floors, all new everything; a/c upstairs(2ton) and 5 ton downstairs.  It cools fine, but it's big and with only 3 of us, we only use about 2 rooms most of the time. Practically a new home. I've was studying underground piping for cooling but I have a new though. I can not use swamp coolers because it's to humid in Middle Ga. I have a well that the water is about 49-58 degrees. If I build a box with a cage fan and use small radiators (desinged for this purpose; not auto radiators), to pass the cold well water thru, wouldn't this work to cool the air for a room or two? I would design it to use a thermostat to open a valve when the water reached about 70 degrees and have it to RETURN the water back to the well (have have an opening to do so on the well). What I'm visioning is, the air would pass a hundred or so coils with circulated cold water all the time. I understand I need to also consider humidity dropping and cycle that out. Keep in mind, I'm not talking about passing air over a wet pad. I'm leaning toward passing air over cold coils that might be as deep as 3 feet. I really would like some detailed opinions. I'll email drawing if I have to.  Best regards.  Chris - Macon Ga.

Posted by opc167 6 years ago

transformer power

I have been thinking about this for a long time now and in therory it works.  What im wordering is if you could make it work in place of the traditional power outlet.  Here it is, basicly there are just coils of wire inside of a transformer, on coil has say 240 turns of coil. Inside of this coil is another coil with 240 turns also.  So the voltige inside the first coil will be the same as the second coil.  And to half the voltige in the first coil.  If you had a plug that was just a cilender with a coil of wire inside and an outlet that was a hole in the wall with a coil inside.  I know a hole in the wall with 120 volts running through it sounds scary , but put a plastic cylinder inside the hole and vurtaly no shock hazerd. sorry for the spelling errors spell check was not working.

Posted by Laserman595 8 years ago

I need help with the placement of my magnets, and how to connect my coils? I plan on using nine coils?

This is my first build and I am still unclear on a few steps. Mostly how many magnets and placement, and how to wire my coils together. I plan on winding 9 coils for a three phase design and I have up to 20 ferrite magnets to use. Any help would be greatly appreciated.

Asked by wheatabx 8 years ago

When I see generator construction they usually suggest 1 stator and 2 rotors.

Most show 1 set of coils with magnets on a disc on each side. How would 1 rotor ( with magnets ) and stators ( with coils on ) either side of it compare? Just to be clear the magnets rotate.

Asked by buteman 8 years ago


post in the comments your coilgun, capacitor bank, and how your coilgun works. I want to know everything about it. EX: how long your coil is, how many layers your coil is, how you built it, etc. The more you put the better. I also would like some advice on my new coilgun I'm building. I want to use flash-capacitors and 26-gauge wire. I don't want to use a lethal amount of electricity if at all possible. Thanks!

Posted by Pyrofan 6 years ago

Electromagnetic and Magnetic Levitation

Hi! I am setting up a levitation system and need to estimate the amount of voltage and current that is needed for a 2" dia. coil to produce 4800 Gauss. I don't have any restrictions/requirements on the core, number of turns, etc as long as it would produce 4800 Gauss with a 2" diameter. How can this be calculated? (I have spent a lot of time googling for such information, but I am pretty confused and didn't find how to calculate this) Thanks!

Posted by J50Nunlimited 8 years ago

DC motor core insulation from windings? Answered

I have recently attempted to rewind an old 240V AC drill motor to a low voltage DC one. After winding the 12 coils I found that all of the windings were shorted to each other, I'm assuming this is due to the thin enamel coat on my wire breaking against the edges of the steel core. As a result I need to rewind it, but I am unsure what kind of insulation to use, tape, some kind of glue or sealant, varnish, I was thinking a hardware store type product nothing online or that costs a lot. 

Asked by The MadScientist 6 years ago

DC magnetics motors and anything else DC

I'm having inventors block figured i'd try to get some other users talking about ideas for dc projects and i'd get a different angle on my work so please post.

Posted by Sessha 6 years ago

Should I use it? Answered

I got this flyback transformer without high voltage cable so I cut it until I found a tiny piece of metal. Is it safe to use the transformer ? and If it is how do I find the best coils to be the primary and the feedback from the 2n2055 driver.

Asked by theVader75 7 years ago

Could you weld with an induction cooker? Answered

Having seen the microwave transformer welding kit and similar projects I started wondering about this one... Induction cookers are basically one side of a transformer and usually just dissipate current in to the pot to heat up the pot. But they've a high number of coils and I've seen them rated at 3000 watts, so if you made a coil that was a few turns of thick wire to be the other side of the transformer you'd possibly be able to have a huge current low voltage supply similar to the microwave oven welder. I imagine there'd be safety devices that may need disabled but the idea of your oven being a welder seems cool to me, especially if someone had a need to weld often and their kitchen was through to their garage.

Asked by killerjackalope 8 years ago

What is this and how I can use it? Answered

I guess it is an old vacuum tube flyback transformer without a ferrite core. If I am right please tell me how to connect it. Thanks.

Asked by theVader75 7 years ago

Secondary coil, tesla coil?

Do I wind my secondary coil in the same direction as primary coil?

Asked by wiccakingkamui 4 years ago

Does it matter how a coil is wound? Answered

Hi everyone, Take a look at the illustration attached.  Is there any real difference in values between the four winding types? *** Assuming same core, same wire gauge and same number of windings on all 4 primaries, and all 4 secondaries *** A) Both primary and secondary are wound TOGETHER. B) primary is wound first, then secondary wound ON TOP. C) Primary and secondary are wound at OPPOSITE SIDES of the core . D) Primary and secondary are wound next to each other on the SAME SIDE of the core. Note that figure in D it seems like the wires are thinner, but I assure you, that's an optical illusion, and the gauge is the same in all 4 figures :-p Again, the question is whether the 4 coils would act the same in a circuit, or is there a difference in values between them? Thanks!

Asked by Morgantao 5 years ago

brushed induction motor confusion? [answered] Answered

My father and I are currently restoring a metal-working lathe, however, we do not have 3 phase power to power the original 0.5HP 3 phase motor. We do, however, have a slightly smaller 0.25HP motor. At first appearance, it seemed to be a simple AC/DC brushed motor with a field and winding on the armature. There was no wiring diagram supplied with it, but in one configuration (what appeared to be the ameuture and field coils) are wired in parallel for 120V operation. This did not seem right, since the field coils will be simply shorted across the mains, but I assumed that since we are dealing with AC and inductors, this is OK. It works flawlessly, but reversing the polarity of either the fields or armature would cause the motor to sit and buzz. If started manually, it took off slowly but sounded awful. I need the motor to rotate in both directions and do not have enough materials to do this mechanically. On closer inspection after dismantling the motor, it appears there are 4 brushes, connected together in 2 pairs. They are not directly connected to anything. The 4 wires coming out seem to be just for wiring both field coils in either series of parallel for 110V and 220V operation respectfully. Perhaps even more strange, the 4 brushes are mounted on a centripetal switch, which disengage the brushes from the armature. I was able to make out on the rust that it said "revolution induction motor." So I reasoned out that after the fields are energized, it will induce an electrical current in a few of the coils on the armature, and the energy would flow to the other 2 sets of brushes, causing a different set of coils on the amature to energize and this would initially start the motor. After it gets going, the switch disconnects all the brushes and the motor operates as a simple induction motor. My father used to rebuild motors for a small company, and this is in fact one of the motors he repaired. Although he is skilled at this practice, he does not understand the operation of induction motors and can only figure out wiring by strictly following a diagram or trial and error. I am curious about what this type of motor even is, and how it works! In th meantime, I will research induction motors and how they work, and see what I can learn.

Asked by -max- 3 years ago

contact coils

Do they make a coil are something that i can use DC to a contact coil for AC?? are like using DC as a switch for a AC realy ?

Asked by DAVjon123 3 years ago

tesla coil resonance

How do i get a tesla coil to resonate

Posted by science kid 7 years ago

Tesla coil? Answered

What gauge wire do I use for my secondary coil

Asked by wiccakingkamui 4 years ago

Tesla Coil

Can someone PLEASE make an instructable on making a tesla coil that shoots sparks???

Posted by MisterHankie 9 years ago

What is the current of an ignition coil?

I need to know the amount of milliamp s of a basic ignition coil ?   (not an oil burner ignition coil)

Asked by The MadScientist 7 years ago

Conical coil inductance calculation? Answered

Does anyone know a reliable calculation or online calculator for conical coil inductance? I am calculating this for a Tesla coil primary if anyone knows is a conical coil primary suitable for a 2000W system?

Asked by The MadScientist 6 years ago

need help for coil gun

I want to make coil for coil gun.i have 21awg copper wire (0.7mm), 250v 10000 microfarad capacitor.How many layer for the best velocity ? 

Asked by Rendydevara 8 years ago

Mini tesla coil? Answered

Is it possible to make a small tesla coil with a toilet paper roll for the secondary coil?

Asked by josh1324 7 years ago

Would this Tesla Coil work? Answered

I am wondering if this DC powered Tesla Coil will work.

Asked by josh1324 6 years ago

Tesla Coil Grounding? Answered

Hi! I made a tesla coil like this guy! But I didn't ground the secondary coil of the tesla coil. It seems to work ok without it, but I'd like to see it preform better. Would it help if I grounded it?  Thanks!

Asked by transistorguy 7 years ago

Tesla Coils

Is there an easer way to make a homemade Teslacoil? Thanks

Posted by spc301 9 years ago

120V MOT transformer on 220V for spot welding machine? Answered

Hello i'm making a Spot welding Machine using a microwave transformer i'm removing the secondery coil to replace with 2 rounds of very thick wire for the output . the only problem is the transformer rated for 120V input Will it matter if i connect the primary to 220v ? i'm replacing the secondery anyway ?

Asked by pixema 4 years ago


Is there any difference between a coil and electromagnet? So, is saying that a dynamic speaker has coil as correct as saying that it has an electromagnet?

Asked by .Unknown. 7 years ago

building a tesla coil

Is there any way to build a tesla coil?

Posted by cris1133 10 years ago

can you ground a tesla coil into an outlet? Answered

I need to know because i am building a tesla coil#

Asked by nerd7473 6 years ago

Coil Gun

Hello! I have a question. I have been looking at making a Coil gun lately and i had an idea for a simple one. Just need to know if it would work. Basically: Battery-->Switch-->Diode-->Transformer-->Coil For my Coil I am using a coil from a Pinball Machine Flipper. Just An Idea for makers of a coil gun.

Posted by BionicB 1 year ago

How to find out the feedback coil and primary coil pins on a flyback transformer? Answered

I have an old one and a newer one. And where is the hv negative?

Asked by theVader75 7 years ago

Small tesla coil? Answered

5000volt neon transformer too many capacitors? Should I just wait tell I can make bigger coil

Asked by wiccakingkamui 4 years ago

how to power a starship coil?

I want to power a starship coil that i built

Asked by nerd7473 6 years ago


Im making the alternator with the 12 magnets, i know that it normally uses 9 coils,I would like to know if I can use 12 coils with the 12 magnet set up and it will be 3 phase but with each phase having 4 coils. I know the wire set up for the star with the 9 coils ,what would it be with the 12 coils. Thanks John

Asked by conntaxman 9 years ago

can a coil gun be made without the camera?

I want to make a coil gun but i don't understand why there is a need of a camera?

Asked by Pranavthegreat 5 years ago

Coil gun projectiles?

Will solid discs (think coin-sized) work as coil-gun ammunition? Or is a hole in the centre absolutely required for the eddy-currents to flow?

Asked by Kiteman 7 years ago

Indicators and generator coils?

Are indicators used in generators

Asked by jambekcom 4 months ago

tesla coil wire

What Gauge. Wire would you use to make a 2 foot tesla

Posted by wiccakingkamui 4 years ago

Space Elevator or Lateral Coil Gun? Answered

What would be a batter way to get off the earth, Space elevator or lateral coil gun?

Asked by nfarrow 8 years ago