Big Joule Theif

[kooler]

backwards jt 2

this is my second video of the backwards jt with a 265,000 mcd led on the battery rail..
just needed to try out a new camera

YouTube - koolerization's Channel

fun circuit since it runs xtra leds with out using anymore ma's

robbie

[kooler]

100 uh

watson
that was indeed a 100 uh inductor but you don't need it if you have a real good pot..
my little cheapo pots are funny acting.. so i went with a better made one and i didn't need it to fine tune it no more..there is a real good schematic on ou site
let me know and i will upload it to a image site

robbie

[Watson]

watson
the plus sign was a short way for me to say ( or greater than )
the inductor gives you better adjustment.. easier to fine tune the circuit thru the pot.. works great with 100 uh to 220uh
i used tinycad and ms paint to do the schematic.. it got smaller once i added it as a attachment to the website..
if need be .. i can post it on imageshack if you want

let me know

robbie

Above you say 100 uH. It looked to me like the schematic was marked 100 mH, but it's too blurred to read. Do you mean that the value in the schematic is 100 uH? It would make more sense than 100 mH, but it looked like an 'm' to me.

Thanks

[kooler]

watson
the plus sign was a short way for me to say ( or greater than )
the inductor gives you better adjustment.. easier to fine tune the circuit thru the pot.. works great with 100 uh to 220uh
i used tinycad and ms paint to do the schematic.. it got smaller once i added it as a attachment to the website..
if need be .. i can post it on imageshack if you want

let me know

robbie

[Watson]

hey guys
this is a update on my backwards joule theif.. inductor installed..
found that even since the transistor is backwards it still has bemf in the same direction..
use the secondary for leds..
check volts on battery after hours of running..

I looked at the circuit closer and I now see what's going on.

It's like a regular JT. But the feedback winding is connected to common instead of the positive. If you connected the feedback winding to the base with a resistor, like a normal JT, there would be no positive voltage to bias the base. So you had to add the DC blocking capacitor and the pot to the positive to supply the base bias.

I'm not sure why the 100 mH choke was put in there. What does the plus sign at the end mean?

THanks..

[Watson]

hey guys
this is a update on my backwards joule theif.. inductor installed..
found that even since the transistor is backwards it still has bemf in the same direction..
use the secondary for leds..
check volts on battery after hours of running..

Nice drawing, a bit on the small side, but really good. What did you use to draw it?

It's a good idea to put a small resistor like 470 ohms in series with the pot. This prevents excessive current when the pot is turned down to its minimum, and the full battery voltage is put on the base of the transistor. Without the resistor, you can connect the battery directly to the base, and the excessive current can damage the transistor.
Thanks.

[Watson]

Incandescent Lamps

@Kooler

Nice circuit ! keep the good work!

@all

I just finish a new video showing my last JT construction , but also the bulb lighting from the battery the E-C connection and the 3 different secondaries .

The E-C on this one is really strong , but this design is flawed , with parallel layers the load is transparent but not on this one ...

Its a good one anyway.

YouTube - MK1 Micro TP Joule Thief

The best is still to come !

Mark

The video is easy to view, not all jumping around like so many others. Really helps with seeing what the coil looks like.

I'm seeing a lot of posts where the light is an incandescent lamp, not a LED. First time I've seen this used on a JT. A Tungsten filament has a positive temperature coefficient (tempco) so it acts different than a regular resistor. If you put a voltmeter and ammeter on a lamp, the current will not go up linearly with the voltage like it does with a regular resistor..

A LED is nonlinear too, but in the opposite direction. It won't conduct until the voltage gets up to a certain point, 2.5 or more volts for a blue or white LED. Then it starts to conduct heavily. The incandescent lamp is the opposite. At low voltages it will conduct very heavily (low resistance) and as the voltage rises and the filament heats up, the current then rises only slightly, like the resistance is increasing. It is!

This is probably why you never see the lamp used on a JT. IF you want to run a lamp from a low voltage supply, you just use a low voltage lamp. But one resulr\t of the different V-I characteristics of incandescent lamps is that the brightness of the lamp can fool the eye into thinking that the effect is due to the JT making it bright. If you use a 2 AAA cell lamp on a JT with the transistor disconnected, it may look bright just from the 1.5V battery, without the JT adding anything. You think the JT is running but it's not.

The JT likes to have a load that is like a LED, where the load doesn't conduct at low voltages. That allows a lot of feedback and strong oscillation. The opposite is happening with the lamp: the lamp loads the JT at low voltages, and tends to damp oscillation.

If you connect the lamp to a winding that is separate from the primary or feedback winding, then the load doesn't occur until the magnetic field is changing, which to me means that the damping effect is not as great, if at all. But then the circuit is not really a JT, it's a DC to AC converter.

I'm aware that people may be bored and turned off with this theory stuff, but if you are aware of what is going on in the circuit, it will help you immensely when you experiment and allow you to get the most out of your project.

Back to experimenting...

[kooler]

backwards jt

hey guys
this is a update on my backwards joule theif.. inductor installed..
found that even since the transistor is backwards it still has bemf in the same direction..
use the secondary for leds..
check volts on battery after hours of running..

[mk1]

@Kooler

Nice circuit ! keep the good work!

@all

I just finish a new video showing my last JT construction , but also the bulb lighting from the battery the E-C connection and the 3 different secondaries .

The E-C on this one is really strong , but this design is flawed , with parallel layers the load is transparent but not on this one ...

Its a good one anyway.

YouTube - MK1 Micro TP Joule Thief

The best is still to come !

Mark

[SkyWatcher]

Hi kooler, thanks for the info. The ferrite definitely does the trick. I'm testing a 2-3/4"L X 3/4"dia. ferrite cylinder with 18 gauge bifilar and it stays cold, whereas the previous coil/core using laminated electrical steel was warm. The ferrite gives nice eff./performance with these high frequency self oscillators. I'll have to get a hold of some more ferrite and try that circuit. thanks.
peace love light
Tyson

[kooler]

Hi kooler, what material is your toroid made of and are you sure the amp meter is accurate and can you compare a normal powered fully lit led with the ones you show in video, thanks.
peace love light
Tyson

hey
the meter is accurate.. it blew me away that it even worked for 8$
but my fluke meter from mactools reads the same..
i didn't compare to a normal brightness led.. and at 5ma they are to bright
but at 1.3-1.7 ma's they are hard to look at..
the 1'' toroid is the 5 for 1$ from goldmine..

robbie

[SkyWatcher]

Hi kooler, what material is your toroid made of and are you sure the amp meter is accurate and can you compare a normal powered fully lit led with the ones you show in video, thanks.
peace love light
Tyson

[kooler]

hey
this is my backwards joule thief 1.2 vdc 1.5 ma's
small video.. sorry i didn't know i said a cuss word till i already uploaded it..
i'm not a bad person..
YouTube - backwards joule thief

i'll post a schematic if you are interested

robbie

[mk1]

@all

NEW MOVIE Slim Version 5 turn 16 layer

YouTube - Mk1 Slim TPJT test

Lighting leds on the satellite coil , and the 2 volt bulb on the secondary .

8 turn secondary about 10 v rectified dc .

[CosmicFarmer]

Ya Lidmotor had full wireless from a JT style setup, if I remember correctly. Might not have been full scalar cohesion, but the DrStiffler tower turned on.

It seems I am walking in your footsteps Jeanna, making the mistakes you made all over again. I just had my numbers backwards when the wallet was out, I thought a low u was desired. So I chose the lowest. Actually they came from Ebay and I saw the words "For flyback" so I thought that people would make flyback transformers out of them.

I'm trying to rationalize my work and expense on the chokes but its all about having the right tool for the right job. Atleast they have plenty of room and I can put the hundreds of wraps on it that it needs

Its just another learning experiment for me I suppose and hopefully someone can learn from OUR less-successes... I dont want to call them failures because I have one choke all wrapped up that can deliver over 200 volts from a dead AA, so I think that is still a success, but if that wrapping was on a different core I might have real fireworks.

The only problem with the CFL toroids is they are TINY... I had cheerios for breakfast that are larger.

Anyway, my discovery for today is my (choke) that I wrapped multiple styles. First test was 3/9/40 and I got about 13 volts, then I increased the primary to 10/10, twisted together, and left the 40 on there and got 23 volts. Removed the primary and rewound them separate (not twisted), and got 27 volts.

I was unable to get scramble wound to show higher voltage today.
Cheers