Joule Thief

[TheNOP]

"A normal light bulb is not much different than a LED as they both produce illumination."

and stop there...because the two are polar opposites in every other way.

any way, you got my point.
both are emiting light.



@jeanna
don't be disturbe by the bridge diode marking, ~ ~  - +
they are not input/output mark per say.
you can put ac on the - + pins and get dc on the ~ ~ pins.
the marking are only to help us to know in advance what pins will be the + and what pin is the -.

from what i make from your explanations your error is to connect the 4 leads to the bridge.
only 3 leads from the coils connect to the bridge, the remaining last lead and the last bridge pin are where you put your meter.

[jeanna]

@jeanna

Try connecting one pair to both ac legs and the DC+ into the other pair try both ways , check voltage between bridge neg and coil output.

I think I did that.

If you think I did not, please put it on the drawing or something like that, because I cannot follow your words very well.

thank you,

jeanna

[jeanna]

from what i make from your explanations your error is to connect the 4 leads to the bridge.
only 3 leads from the coils connect to the bridge, the remaining last lead and the last bridge pin are where you put your meter.

I connected the meter to the ac lead and then to the last wire. That was where the drawing said to put the load. MK1 said this was the meter.

Here is how:

First I set up all the 4 wires as I described, then one at a time I removed a wire and inserted the meter between it and the bridge point where it had just been.
Then I replaced that wire and moved on the the next one. This is how I arrived at those 4 voltage readings from the 4 points of the bridge.

I cannot understand that schematic any other way.

thanks,

jeanna

[TheNOP]

You are right but tesla did light incandescent light bulb, from hv pulse.

the story does not tell us with how many initial watts he did it.
well, i am not aware of such data so...
i would not go as far as saying that to prove if a jt can light a normal bulb or not.

[xee2]

@ jeanna

On the + end of the bridge I get 37volts
On the - end of the bridge I get 51volts
On one of the ac ends I get 3volts
on the other of the ac ends I get 47volts.

   I do not understand this. The voltage should be between the + and - outputs (with meter set to DC) or between the two AC inputs (with meter set to AC).

If one lead of voltmeter is on the + output and you are getting 37 volts, where is the other lead of the voltmeter connected?  It should be connected to the - output.