Joule Thief

[hartiberlin]

Hi,

I have done a little more research on the circuit. I wanted to run the circuit from 2 AA batteries in series
and get more light out of the LED lamp. I assumed that if I reduced the number of turns on the primary
from 25 turn down to 20 turn, then I would get more output at a higher amp. draw on the input. I assumed
wrong. My circuit did not run at all with 20 turns! So instead I increased the number of turns to 29 and
now the circuit runs fine. So I assume that if I want a higher output voltage then I must increase the
number of turns on the secondary coil. I might be wrong on that also. :-) Have not tested this yet.

I have also tested the circuit on a larger LED lamp. A OSRAM 230 VAC 8 Watt lamp. The circuit did not oscillate
due to the higher load and less feed back to the base of the 2N2222 transistor. Maybe a variable resistor to give
the base of the 2N2222 transistor a bias voltage will help. I have not tested this yet.

Added 1, I have now tested the circuit with a 10K variable resistor. Works great. Circuit auto start at power up.
I can adjust the current usage and get what ever light output I want in the LED lamp. Current usage do go up
at higher bias voltages and transistor get warmer at higher wattage, but this is to be expected.

GL.

Hi GL,
well done.

I am also trying to replicate the new circuit over here from Laserhacker:

https://www.youtube.com/watch?v=Zt5zulKQ1XE


The video is pretty confusing.

Where does he connect the ground wire ?
to the other pole of the LED bulb, where not the base is connected ?

WHat is this graetz bridge rectifier doing there ?

It seems he can just run it from his body electricity and the other side of the circuit is just only connected  to the ground ?

Regards, Stefan.

[plengo]

Fella Overunity members,


moderation rights resolved. Things are back to normal again, Groundloop and Bill are the moderators now.


I never had the intention to disturb the forum, so please forgive me for the incident. Stefan has fixed the whole issue.


Lets again, continue the great work.

Fausto.

[Groundloop]

Hi GL,
well done.

I am also trying to replicate the new circuit over here from Laserhacker:

https://www.youtube.com/watch?v=Zt5zulKQ1XE


The video is pretty confusing.

Where does he connect the ground wire ?
to the other pole of the LED bulb, where not the base is connected ?

WHat is this graetz bridge rectifier doing there ?

It seems he can just run it from his body electricity and the other side of the circuit is just only connected  to the ground ?

Regards, Stefan.

Hi Stefan,

I did read (over at the laserhacker forum) that you only have darlington transistors to try. I have tried darlington
transistors in this circuit and it did not work well. The reason is that the darlington has a built in diode over
the collector and emitter. The darlington also have base resistors built in. The built in diode is "killing" the
negative oscillation to ground. And I also noted that the darlington transistors heated up in this circuit.

Best result is with a relative high voltage power NPN and a small signal transistor like the 2N2222.

GL.

[Groundloop]

Fella Overunity members,


moderation rights resolved. Things are back to normal again, Groundloop and Bill are the moderators now.


I never had the intention to disturb the forum, so please forgive me for the incident. Stefan has fixed the whole issue.


Lets again, continue the great work.

Fausto.

Fausto,

And you are also a moderator. Better with several moderators so that vi can cover the different timezones.

GL.

[hartiberlin]

Hi Stefan,

I did read (over at the laserhacker forum) that you only have darlington transistors to try. I have tried darlington
transistors in this circuit and it did not work well. The reason is that the darlington has a built in diode over
the collector and emitter. The darlington also have base resistors built in. The built in diode is "killing" the
negative oscillation to ground. And I also noted that the darlington transistors heated up in this circuit.

Best result is with a relative high voltage power NPN and a small signal transistor like the 2N2222.

GL.

Okay, I see.

I  only have here  BD 139, MJE 1100 and PNP Darlington
BDV66B

And a few MOSFETS like IRF 640 and IRF 840.

Can you get it to work with an IRF 840, because that is the cheapest MOSFET transistor ?

I guess MJE1100 does not have an internal diode but base resistors...

Hmm, these Datasheets are showing sometimes wrong pin connections... so you have to be carefull
noit to mix it up.... I just struggled to get a basic darlington to switch right...I had the pin connection wrong
from the datasheet, sometimes they show the view from above and sometimes from below from the
heat sink back view...Damn... I don´t have a 3055 here right now...

Regards, Stefan.