R2 and 100 pf capasitor is just for protect diode. Think, that kan do 420 kilomhs resistor? It have wery big resistance. And 100 picofarads is also wery small capasistance, to make some changes to whole work.

My suggestions.

Quote from: MenofFather on March 15, 2014, 09:05:52 AM
R2 and 100 pf capasitor is just for protect diode. Think, that kan do 420 kilomhs resistor? It have wery big resistance. And 100 picofarads is also wery small capasistance, to make some changes to whole work.

I agree that the resistor is too high to have a significant influence. The capacitor, on the other side, is, somehow, increasing the reverse recovery time of the diode. I still don't have an idea what will that mean to the circuit. I'm trying to assemble it this weekend. I will let you all know what I found.

Regards,

Black Bird

Dear All.

I would first like to thank you all for your comments. They are appreciated !!

Having looked at the second video that was posted earlier it left me in no doubt that we have copied the correct schematic. That is really good news!!

MenofFather's recent post also jolted me, LED's are DIODES !! A one way flow !! This could be a key?? Perhaps the only way it will work is with a forward flow ??  All conjecture, I know but worth mentioning, non the less !!

Dear Forest, keep going man !! You are streets ahead of me !! The transformer could be wound in many ways we just need to find the right configuration !!

Best wishes, cheers Grum.

Quote from: Grumage on March 15, 2014, 09:44:22 AM
Dear All.

I would first like to thank you all for your comments. They are appreciated !!

Having looked at the second video that was posted earlier it left me in no doubt that we have copied the correct schematic. That is really good news!!

MenofFather's recent post also jolted me, LED's are DIODES !! A one way flow !! This could be a key?? Perhaps the only way it will work is with a forward flow ??  All conjecture, I know but worth mentioning, non the less !!

Dear Forest, keep going man !! You are streets ahead of me !! The transformer could be wound in many ways we just need to find the right configuration !!

Best wishes, cheers Grum.

Dear Grum,

Voltage at C3 is already DC, with probably a small ripple. I think that what could be important is not only the one way conduction, but also the non-linearity of the LEDs ( which are diodes). That would cause a non linear voltage feedback to the TL494 by means of R5, which is sampling the LEDs currents.

Cheers,

Black Bird