Hi Guys and Gals was wondering if someone could transpose this 5volt circuit to 12volts
thx

 

What is the purpose of the circuit?

 

What is the rated forward voltage of each LED?

 

the forward voltage is 1.8v to 2.1v, the purpose is the led on the base is a flickering led, like a candle but not very bright hence the 1 watter.

 

Replace the 620 Ohm with 470 Ohm. Replace the 2 Ohm with 39 Ohm. Use a 2N2907 (or similar) for the PNP.

 

Cool, Thank you Alec I'll give it a whirl, I'll let you know how it went.

 

...the purpose is the led on the base is a flickering led, like a candle but not very bright...

The brighter LED should flicker along with the dimmer one, which acts like a controller. Do we know that it works OK at 5V?

 

Yep works perfect on 5v, I tried it with the resistor changes only have a bc327 at home, but doesn't work, the brighter led just stays on, no flicker, maybe the transistor

 

It's not the transistor (assuming it isn't damaged and you have the pins right). You need to tweak the base resistor to get it to turn the transistor on and off with the flicker. Too small and it's always on, too large and it won't go off.

 

You need to tweak the base resistor to get it to turn the transistor on and off with the flicker. Too small and it's always on, too large and it won't go off.

Good point, Wayneh. Perhaps try ~1k-2k?

 

Yeah good idea I'll try a pot to get it right, thanks guys