Lab Power Supply
My old power supply didn't have a current limit and was not protected against short circuit.
I changed the circuit to this one because the original burned out after a short on the output terminals.
I wanted to have a higher output voltage then the original, therefore I used a 2*12V 2*5A transformer I had lying around (bought it at a garage sale).
The ciruit I'm going to use this time:
The display print covered the entire front off the power supply. Because of that there was no space to put an extra potmeter to regulate the current, so I decided to build new voltage and current meters.
I mounted a new heat sink because the old one wasn't big enough.
(The bracket is used to press a TO-220 heat sink to the head of the transistor for some extra cooling)
The supply for the panel meters had to be isolated from the main power supply, so I build a small pcb with 2 7805 powersupplies.
Today I made the front panel. It is printed on photo paper and glued to the front. The result:
This circuit comes in the place of the ZN458A:
Today I received the zener ic's, and soldered them in. The power supply is now finished.
The displays are not as bright as it may appear on the picture.