Lidmotor's Penny circuit help needed.

[Dark Alchemist]

www.youtube.com/watch?v=S1FTnxstQY4

That is the simulation I did and I can't figure out how to get it to do more than 28ma at 0.5v (any higher volts makes it go crazy).

[TinselKoala]

The circuit is a Joule Thief variant. I've re-drawn it using a more standard "rail-to-rail" layout so that the JT-ness is more obvious.
Please check my schematic re-draw for errors. I couldn't quite make out the value of the base resistor-- it looked like 400k but please correct me here if I got it wrong.

I am confused about your "28 mA". Please explain what you are talking about here. The JT produces pulses through the LED. The current during the pulse will be a matter of the "turn-on" voltage of the LED and its resistance, or fwd voltage drop, and the supplied peak voltage value from the JT oscillator. I see nothing in your sim or schematic that allows measurement of current here.

[Dark Alchemist]

That looks about right except it is 800k resistor not 400k.  He managed to get this to work at .5v but max is 28ma with my mods but a higher voltage, or ma requirement, and forget it.

[TinselKoala]

OK, I'll correct the schematic to read 800K for the resistor. thanks.

But I still don't understand this "28 mA" and "higher mA requirement" that you are talking about. Do you mean input current from the 0.5 V source?

Please tell me exactly where this "28 mA" figure is coming from, and what you do to change it to, say, 29 mA that doesn't work.

JTs that are designed for very low input voltages will often "saturate" and stop oscillating if given too much input voltage. That's not so unusual.

[Dark Alchemist]

OK, I'll correct the schematic to read 800K for the resistor. thanks.

But I still don't understand this "28 mA" and "higher mA requirement" that you are talking about. Do you mean input current from the 0.5 V source?

Please tell me exactly where this "28 mA" figure is coming from, and what you do to change it to, say, 29 mA that doesn't work.

JTs that are designed for very low input voltages will often "saturate" and stop oscillating if given too much input voltage. That's not so unusual.

The video showed what I meant by 28ma and .7v and 1v I don't consider too much voltage but I think this circuit does.

28 ma LED and that box (sorry I assume people have multisim) you saw me open that is where you can change the If of the LED.  I can change it all the way up to 28ma and it works but at 29ma it no longer will power the LED on.

So, I am wanting a way to increase the circuit's ability to power a LED beyond 28ma.