Joule Thief

[jeanna]

@ jeanna

I think you should just try reducing the number of turns. I do not think you will be able to correctly move them farther apart. The most interesting voltage would be the AC voltage between the secondary coil leads with nothing attached. The low value DC voltages you got were because you were measuring AC voltage using a DC setting on the meter.Adding a bridge rectifier might be interesting, but I think not having one is not your problem because all of you LEDs seem to be able to light up, just not at the same time.

EDIT: You can keep removing turns until the AC voltage between the leads of the secondary is 4 VAC when nothing is connected to them.

So, you are  saying to measure the ac across the 2 ends of a secondary without a led on it at all.

Reduce it until I get 4 volts AC. That is twice what it reads now on the one with 2 leds.

at the same time,

The jt with only 1 led on the 2-y shows no 0.00vdc voltage at all across the lit led. (even though the same meter reads 0.73Vdc across the basic led and 0.53 across the 1kohm resistor at the base.)

@all,
I do have a bridge rectifier and also I have maybe 4 or 10 diodes I could use in jim's fashion but I still don't know what I'd be connecting it to.

is this not a separate circuit? The 2-y is a separate circuit in a way, cuz it is unconnected by wires to anything in the actual circuit.

Am I now supposed to connect it into the jt circuit?
I need to have that answer before I can even begin.

Here is how I understand what I am being told to do.:

I put the 2 AC connections of the bridge to either side of the led , then I connect + at bridge to + at battery, and - at bridge to - at the battery.

Also a related question is,
since led's are diodes, why wouldn't I be putting them into a ring formation and getting the light at the same time I rectify.

Thank you all,

jeanna

[Mk1]

@all

I bought 20 gauge brass and aluminum wire and here are my first result on brass, i used it on a regular jt 8 turns of brass (Jt16/16), nothing on either ac or dc ,
But the led works on it , so to rectified everything the volt meter doesn't see much.

Always check with a led it will show you that the meter blind in some cases..

[Mk1]

@jeanna

The pickup coil dose not need to be connected to the jt circuit in any way , only to the bridge, only to the bridge for now.Lets keep it simple for now.

I know it doesn't make much sense but do it .

[jeanna]

@jeanne

The pickup coil dose not need to be connected to the jt circuit in any way , only to the bridge, only to the bridge for now.Lets keep it simple for now.

I know it doesn't make much sense but do it .

I think I am getting closer. -

so, on your diagram... at the ~ symbols connects to either side of the pick up coil because the ~ means ac and ac is happening on that pick up coil.

Now what? Do I put the led on the + and - marks? And do I need to do this for each one?

Am I closer?

Thank you,

jeanna

[xee2]

@ jeanna

I think you are getting too much help. Mk1 has built the circuit and I haven't, so if he is willing to help you I suggest you follow his instructions. The voltage across an LED is usually set by the forward voltage drop of the LED and will be the same no matter what battery voltage is used to drive it. A resistor is usually used in series with the LED to drop the battery voltage to the correct LED voltage, but when only a small amount of current is available the resistor is not needed.