high voltage joule thief!

this is how to make a high voltage joule thief!
the ones i made were 90 and 180v but the more
hv turns you do the higher the voltage(about 1v per turn)
this circuit runs best @2.4v-3v

Step 1 Materials.

you will need:
toroid core(ferrite)
2n3904(sometimes others work too)
512ohom resistor
winding wire(0.15mm approx)
0.2-4mm as well!
neon glow lamp (i used maplin rx70)
time!

Comments

[baven]

Hello there i got problem with this circuit. I got exactly same setting as you with same turn ratio same resistor and transistor and voltage too but when i insert the batterys i get no voltage on the hv output. Any suggestions where could be the problem ?

[inspecter gadget]

Hello, have hit the very frustrated stage?? Have built a tiny 8t Bi-fil version which worked fine -same transistor as in your set up......I have since made your version and have had no luck-only that the transistor starts to head gradually.....I'Ve used [2] different ferrite's and thicker wire----?????????? Anyone have any suggestions

:-Have done some research as some ferrites have low or high Hysteresis -understanding that some saturate with magnetic field and some enhance field strength /Flow.....?

[NatureTM]

Thanks for the example. Multimeter shows 500V, however not enough current to light the neon bulbs I have on hand. Skin test doesn't produce a shock feeling either. I'm going to school for CE and just finished my "circuits" class. Armed with my incredibly basic knowledge, I would guess this power supply has an extremely 'high internal resistance.'

[wateenali]

hi there thanks for this great tutorial.I made this circuit and it generates high voltage but the current is too low and it unable to lightup the led bright i cant understand i check the voltage on the meter and it is more than 500v.Please help to solve this problem.
Cheers

[R.A.T.M]

thers no current the thin your hooking it to drops it drasticly giving 3-6 v off

[raja26]

I have tried with a thick wire for high voltage output and a much thicker wire for low voltage input.. It works very well.. I didn't connect a resistor though, it can run two 3V LEDs with a single AAA of 1.2V..

The only problem I've got is the heat that builds up in the transistor(2N5294). My another doubt is, whether we could modify the setup to run a dc motor, like simple rectifiers or something.. Thanks for the great instructable. Been searching for a guide to increase DC voltage.

[Alex1M6]

Adding a resistor to the base might help with lowering the amount of heat the transistor produces.

[raja26]

Hi Alex, Thanks for replying. I have figured it out by myself. But can you just tell me how I can run a DC motor with it.

[Alex1M6]

Could you try placing the motor in place of the LED? If it does not run use a 3v input with two AA battery's in series.

[raja26]

Thats not possible, because the motor runs with just the battery itself, so when using the Joule thief setup it should be working normally. But the output from joule thief is a pulsated DC. I have to convert it to pure DC for making it work. I just want to know what type of capacitor and inductance to use it as a filter for the DC output.

[Alex1M6]

Oh, in that case you might want to try adding a capacitor across the motor terminals. Try different values and see what results you get.

[Robot Lover]

I believe a simple ceramic disk capacitor will do.

[raja26]

Thanks for the relpy Robot Lover. I'm a zero in electronics, so I don't know about these ceramic capacitors and all. All I can do is try some Random Capacitors.

[Alex1M6]

Hi, Sorry about my comment. I just assumed you had electrical knowledge, I tend to do that sometimes with people.

Have a look at the image I have attached it will show you a ceramic capacitor in parallel with the motor and give you an idea of what to look for.

[raja26]

Wow, thanks for this quick help.. By the way, what will be is capacitance?.. This is a fair picture.. Much needed help indeed..

[raja26]

Yeah, thats what I'm looking for but is capacitor alone is enough? Don't we need inductance?. I don't know much about capacitors so please specify some value for that one 1.2 V AAA battery.

[sdobbie]

Would an n channel enhancement mosfet work instead of the transistor. I have a p60nfo6 mosfet and a k3567 mosfet.

[acmefixer]

No. The MOSFETs require a much higher voltage than 1.5V.

[timdgoodpaster]

I used a 100 volt 3 amp mosfet, had to change resister to 33 ohms and a 9 volt battery. the battery life is short pulling one amp.

[Mudbud]

I can not find a 512ohm resistor anywhere! what else can I subsitute?

P.S no Im not going to get one online, I'm not old enough. :)

[acmefixer]

The standard resistor value is 510 ohms, green, brown, brown, gold.. If you can't get one of these, then get two 1000 ohm resistors and put them side by side and fasten their leads together (in parallel). The two will be the same as 500 ohms.

[NcssR]

hey guys,at this joule thief works a c945 or bd 139 or sdt9208 power transistors

[andy]

I have followed the instructable and found the voltage I'm getting to be a lot lower. I got the circuit resonating at about 24ohms on the resistor, but I always seem to require a capacitor between the Hv outs. The highest voltage I got was 30v out, changing resistor values decreased voltage significantly +/- 10ohms dropped to about 15v and further than that pretty much nothing. Changing capacitor values changed frequency but voltage was effected lesser than by the resistor (+/- 5 volts at the most) 33uF seemed to be giving the best result, any less and the oscillator wouldn't fire. Toroid was 100 turns against 10 tapped in the middle (5/5). The torioid is almost exactly the size of 2 stacked pound coins, 10/12ths of an inch across and 4/12ths of an inch deep. Curiously using a 1.5 volt source (as opposed to three) only dropped the hv out by 5v to (25 volts out). Also the wire I am using is significantly thicker than that shown, at 30SWG (0.315mm). Does anyone have any idea's what could be happening? Would increasing my Hv voltage (by three times) just require (3 times) more turns on the Hv coil, or is it more complex than this? Any help/explainations appreciated, Thanks

[rayfalcon]

try to use a 2200 uF in your project and see how many am/ volts you get then However DO NOT get into the path of it trust me i have done it, my parents picked me up off of the floor.
Charles

[andy]

Capacitors on the output severely reduce the output voltage for me. I think it's because the toroids are from an old (PC) power supply. I think what is happening is that there is a limit to the speed at which the toroid allows the circuit to oscillate, in effect capping the maximum value. A torrid a friend gave me a long time ago is not limited by this effect, and produces upwards of 100 volts however it requires a very high turn ratio, roughly 3tap3 to 300 turns. Even in this case the capacitor ruins the resonance and drops the output to around 20/30 volts. I suspect the issue is the type of toroid core (powder/solid etc).

I know what you mean about the high voltage, I once accidentally shorted a camera flash capacitor with my fingers, it was like being punched in the arm, and left a nasty little path of dead skin into my finger. I have been very cautious of high voltage since then.

I have never had good efficiency with this circuit, even the successful coil burns 60 to 70% of it's power depending on source current and voltage. Having said that it could drive a "low" voltage (fires at ~110v, stays partially lit right down to 70v ) Nixie tube for a couple of days on an 1000mAh 1.5 volt cell, which was fairly impressive. Currently I am looking into more efficient circuits. A 555 timer based version seems promising.

Drew

[rayfalcon]

what? No high voltage warning lmao little bit too late to worry about it now, after i already got the chit knocked outta me.....I had to test it to see if it was actually "high" voltage ( not really) but i accidently got into it while adding finishing touches to mine ( i forgot to take my battery out ) You need your warning up there so no one can say hey you didnt tell me and such and such got hurt ;-)
Great instructable 10 + rating and 5 stars

[PKM]

Do you know what the waveform of the output looks like? Are the edges sharp enough to drive something like an ignition coil? I'm thinking of something like this- battery powered Jacob's ladder FTW :)

[Adam Manick]

That is not battery powered. You plug it in. And yes you can get nice arcs from this circuit with a little improvement.

[12V]

the first picture is when under no load and the second is with a neon wire ended lamp.

[ramatern]

OK, now I'm interested. What I'm looking at is a sine wave. Why can't I get an inverter to give me a nice sine wave like that? Can I adapt this to function as an inverter? ;-)

[PKM]

Awesome, O-scope traces- I was half expecting a response along the lines of "WTF are waveform edges" or "no" or something. Still, that looks like a "no" because it's near sinusoidal with a load on it. Oh well.

[Xellers]

555 timer

[12V]

i do know of another circuit that is a load of dc pulses
but i haven't got o-scope traces because mine broke so i have to make another circuit.
when i made a circuit i will take more o-scope pics.
[http://www.talkingelectronics.com/projects/FluorescentInverter/FluorescentInverter.html]

[mattccc]

will someone try to make a florscent tube driver with this

[Adam Manick]

OK I am actually going to try that. The only difference is that I am using a 120 volt to 12 volt step down transformer.

[omnibot]

Here's a 12v for 40w tubes

[12V]

i might if i can find some bigger parts.

[gizander]

I have a bunch of 0.5mm wire left over from a previous project...will it work instead of the 0.2-0.4? thanks...

[Adam Manick]

Yes. but it may have a different effect than this project is intended to have.

[harshpatel1692]

Can we use a 6-0-6 :240 transformer instead of the toroid windings