Joule Thief - Detailed Build

[@pyotrleflegin7255]

Informative video -- thank you. This is the clearest description I have ever seen.

[@tsbrownie]

Thank you.

[@abgates56]

All the other Joule Thief circuits I've seen that use these components wrap the coil with a 1:1 turn ratio. Will this work with 1:1 or is 1:2 turns ratio required? Thanks for the great video!

[@tsbrownie]

Ratios can raise or lower the base's voltage allowing one to run with more or less voltage. I got a new (usable) oscilloscope so I should put it to good use on that.

[@pleasecho2]

I must have sat through a dozen DIY joule thief videos and in not one did the "expert" mention: 1. How long a wire you start out with for each winding, 2. The gauge of wire and 3. In what direction you wind each one (same for both or opposed)

[@tsbrownie]

Good points 1) depends on the size of the coil. If you measure the 4 sides of the toroid, then multiply by the number of turns you want, then add a bit extra for connections that's the length. 2) wire size is not terribly important, but if it's too big, it won't go many rounds through a small toroid. Using the area of a circle of say 0.5 cms radius, then the area is about 0.8 cms^2. A wire of 0.5 mm^2 (0.005 cms^2) including insulation will THEORETICALLY pass through the hole 160 times. Don't count on it being anywhere near that; there's lots of air space, etc. 3) I have a video on winding a toroid. The conclusion is it does not really matter much.

[@pleasecho2]

Thanks that helps

[@Blakehx]

Good info as always, thanks! Will you show how to make a high power joule thief flashlight with super capacitors instead of batteries?

[@tsbrownie]

Thank you. I've got 2 super caps and I'm not impressed. A "dead" battery will run much longer, and you get to "recycle" the battery right up to the end. I am looking at using body energy to create electricity. What do you think of that?

[@Blakehx]

Sounds like a cool idea, I'd love to see it! Are you planning to use a Peltier module or something? You might be able to make it work pretty well as a headlamp with the Peltier against your forehead!

[@kennethlibe9941]

I am currently having an investigatory project regarding the body energy to create electricity. Im planning to try this video u created to help me boost the voltage of the peltier module. btw can anyone help me make this possible?

[@saddabadda7921]

Really helped to me. A lot👍 you're information. ....😆😊😏 THANKS. .

[@abgates56]

Most Joule Thief circuits I've seen that use these components connect the Transformer in the opposite direction. That is, the "center tap" Transformer lead is usually connected to Battery Positive, and the other two Transformer leads are usually connected to the Transistor Collector and Transistor Base. In your circuit, the "center tap" lead is connected to Transistor Collector, and the other two Transformer leads are connected to the Transistor Base and Battery Positive. Does it work equally well either way, or is there an advantage to your method? Thanks!

[@tsbrownie]

The circuit I use is a redesign of one from a 1970s era transistor checking circuit. I chose it because it was developed by experts at such circuits. I have not tried the other configurations and I really should; it would be interesting. I will have to put it on my list of to-dos.

[@ZeedijkMike]

With a proper made joule thief you can easily run a couple or more of 3 volt LED's So no need to use a "low voltage" LED's

[@tsbrownie]

It depends on what you want. If you use a very efficient circuit, including LED, you can run one on a watch battery for days. If you build it bigger and more robust you can power LED arrays or even fluorescent bulbs! So there's a tradeoff. I prefer making tiny ones. I'm thinking about making a huge one...

[@Blakehx]

I'd like to see a huge joule thief circuit, and the schematic!

[@Blakehx]

If I want it to be brighter, should I use 1 higher power LED or can I connect multiple LEDs (connected in series or parallel)? Thanks!

[@tsbrownie]

Your question is hard to answer. It depends on the voltage and current output of the joule thief. That depends a lot on your coil. And it also depends on how much voltage and amperage your transistor can handle. And input affects output. The concept of a joule thief is to operate on very little power, so most people either make it small and very efficient, or make them huge (and big ones can produce dangerous voltages). So let me try to give you a starting point on experimenting. I would use the same coil. I'd probably use a bigger NPN transistor. Decide how you will power it (maybe 1 fresh AA battery). Then start adding LEDs in different ways, serial and parallel. See if you like it, change it, ...

[@chongshenchang9367]

@@tsbrownie Here you are talking about the output, but what about the input??

[@craignehring]

Nice & Neat Good tutorial as well

[@karensmith5510]

What is the O.D.and the height of toroid that you used, and the gauge of wire you used. My brother has some small toroids. He has tough me some about electronics. I want to keep it as close to yours, because yours works good.

[@tsbrownie]

The wire gauge is not critical, so long as you get the number of turns you need. This is wire wrap wire. The toroid is 1 cm across the outside. It's black (the colors indicate different "speeds".) It's not that critical. The bigger ones work just as well, but they are not very convenient.

[@karensmith5510]

Thanks. This is small and will fit nicely inside of a solar powered landscape light. The light stays lit for about 4 to 5hrs, this should extent the on time. After all it is only 1.2v to begin with.

[@kevfrets]

Excellent!!

[@tsbrownie]

Thank you.

[@chongshenchang9367]

Is it copper coil or just a random wire. And can we work out with BC 547 Transistor?? And your coil primary and secondary connection is not clearly visible or explained. Can you explain it better?

[@tsbrownie]

The wire is insulated copper. The BC547 is NPN and it will probably work (but I've never used one). I show how to wind the coil and include a circuit diagram. I am not sure what question you have on connecting the coil.

[@UpcomingJedi]

With 2 color wires on the toroid, how is it hard to determine that the coils are not wired in opposite polarity like they should be?

[@tsbrownie]

I did a video on that. Turns out there's not much difference as far as this circuit is concerned.

[@hizonopusdie]

Can I use 2N2222A transistor instead ?

[@tsbrownie]

I have never used one, but from the specs I would guess it would work.

[@hizonopusdie]

I have a 2N2222A (TO-18 package) having a hard time finding its emitter, base and collector

[@swasthikprasanth1539]

can we use copper wire instead of the blue and brown wires

[@tsbrownie]

It MUST be insulated wire. It can have plastic or enamel coating, but it must be insulated. Note that the core can have shape edges and can cut through insulation. Also, vibration can wear through insulation (the core is very abrasive) so if you want it to last a very long time, you can dip it in enamel to lock the coils in place and keep them from moving and rubbing.

[@swasthikprasanth1539]

so inside the insulation it should be copper wire

[@tsbrownie]

Yes. If you are very rich, you can use gold or silver wire, but it must be insulated in any case! ;)

[@corysamoila]

Awesomeness thx

[@swasthikprasanth1539]

what wires have you used ,is it copper wires and are both the blue and brown wires the same,pls reply

[@tsbrownie]

The wires are ordinary. Bigger wires are lower resistance, BUT they are harder to wind and you can not get as many turns.

[@chongshenchang9367]

@@tsbrownie what if we take bigger core?

[@tsbrownie]

@@chongshenchang9367 A bigger core will probably work, but it should be the same color (black in this case).

[@affanahmad5932]

What if i use a 200 ohm resistor will it work.?

[@tsbrownie]

It will work, but the voltage flyback may spike the base, damaging the transistor.

[@affanahmad5932]

tsbrownie ok then 1 k ohm is better and im using a 2N2222 transistor will that do

[@affanahmad5932]

tsbrownie thank you very much i finally made it

[@tsbrownie]

1K is kind of a general value for a "dead" battery. If you have more input voltage you need more resistance and vice versa.

[@tsbrownie]

Congratulations!

[@multitasking9763]

27 = 0 what a good vid

[@Datlaai1]

Joule Thief runtime ?

[@tsbrownie]

Depends on the battery. Can be many days even with a very dead battery.