Hi, i'm back...again! Still trying to get this thing reliable.
It failed this time due to an over heating tl431.
The circuit is as the last posted image immediately above.
RL is a 20w8ohm resistor. The tip147 doesnt get hot, but the resistor does naturally.
I've found a new tl431 and stuck it onto a heat sink. even so, it still gets very hot and smokes at 2amp/15v through the entire circuit.
Any help to take some heat off the tl431 would be greatly appreciated.
Cheers
Steve