Joule Thief

[resonanceman]

@all

any luck replicating Koolers last circuit?  No luck here!!!  I was able to light a bulb with my TPU for a few sec's but nothing good to post!

stprue

I have not   tried  the whole circuit.
I  have been playing  with putting  a cap across the  output.
It seems to help some .
The  LED array lights at least as bright as before but  the voltage  is much lower.
The array is  at least as bright   running on 70 V  as it was  running on 250 V

With  a cap that is  to large  I get nothing .

WIth the setup  I have  I am not trying to push  the power limits .
I  have burnt  up  enough  stuff in the last month or 2 to last me a while.
I am  going to keep  the power level low .....and my transistors cool


gary   

[kooler]

this cap right here seems to be the secret
http://www.goldmine-elec-products.com/prodinfo.asp?number=G12714

it charges alot faster than a electrolytic cap of a lower value

and it will hold 532 vdc easy...lol
and the 1'' toroid with 16-20 turns does help recharge faster but i can't get no faster
so off to something else

[stprue]

stprue

I have not   tried  the whole circuit.
I  have been playing  with putting  a cap across the  output.
It seems to help some .
The  LED array lights at least as bright as before but  the voltage  is much lower.
The array is  at least as bright   running on 70 V  as it was  running on 250 V

With  a cap that is  to large  I get nothing .

WIth the setup  I have  I am not trying to push  the power limits .
I  have burnt  up  enough  stuff in the last month or 2 to last me a while.
I am  going to keep  the power level low .....and my transistors cool


gary

lol yes I burnt up my 2 6w bulbs with my TPU and photo caps!!! Thanks for the reply.

[stprue]

this cap right here seems to be the secret
http://www.goldmine-elec-products.com/prodinfo.asp?number=G12714

it charges alot faster than a electrolytic cap of a lower value

and it will hold 532 vdc easy...lol
and the 1'' toroid with 16-20 turns does help recharge faster but i can't get no faster
so off to something else

I see, I need to get some film caps.

Thank you!

[crowclaw]

I see, I need to get some film caps.

Thank you!

@ stprue
The higher the resonant frequencies you are working at the smaller value of capacitance you will need. Those who are able to couple a scope to the DC output will see how effective the inductor and capacitor combinations work to smooth out the pulses. using a large value capacitor is of no advantage at HF, it takes far to long to charge up before you can put the output to any use. Poly carb/ film capacitors are ideal. When working with low output voltages some small gain can be had by using schotky diodes, they have a slightly better forward voltage drop than conventional diodes. Try also using high speed switching diodes in your HF circuits they are more efficient (BA157 etc.) use them to make up your bridge rectifier circuits. If you are using audio or small mains transformers in self oscillating circuits, they tend to resonate at much lower frequencies so again you will have to select a larger value of high voltage electrolytic smoothing caps of 10uf_47uf. Be careful to get the polarity correct!! and be safe. Kind regards Merv