Hi all
Many thanks for all the response and help to my 1st post , I have more information on what my friend is trying to do , the aim to to fit 100 leds in a totally enclosed box in series to 220v ac, could someone tell me if the circuits in the previous post would carry that amout of leds or would he have to change the resistor or capacitor.
Thanks once again.
Rayh

 

Please refer back to your 1st topic :
http://www.electro-tech-online.com/v...ic.php?t=15250

As i had said, the capicator had alreadly limit the current to 20ma which is normal current to drive led. To calculate how many led you can link up, you need to know your led forward voltage. For norminal white led which is 3.2v, for a an amount of 100, it will be a total foward voltage of 320. Using 220AC x 1.414 give you around 311VDC which is not high enough for 100 leds. You may consider using lower forward voltage led, or reduce the amount of leds in your series.

As for components, you do not really need to change any value even if you are driving 1 led or 80 leds in a series as all left over voltage will be taken care by the suppressor capicator.

 

You seem to be starting a second thread on the same issue. Please handle this in the initial thread.