This is a very
simple and adjustable voltage power supply. Max input voltage is 37V and
output adjustable between 1.2 to (vcc - 3) volts.
Q1 is a power PNP
Darlington transistor and is used to boost current of LM317.
It's the most useful
adjustable regulator and for this circuit you can also use LM317L thats can
give 100mA, thats enough for transistor bias.
D1 and D2 are protection
diodes because when you turn the circuit off the output capacitors
discharing and can damage the transistor or regulator.
R1 is 2W and
other resistors are 0.25W
R1 is LM317 current limiting resistor and R2
is Q1 bias resistor all capacitors are 50V RV1 is 5k multi turn volume
100nf capacitors are in parallel with electrolytic
capacitors to remove high frequency noise because large value
electrolytic have large ESR and ESL and cant remove high frequency
I will design a pcb
for this circuit and add to project .
Q1 need heatsink and small
Circuit maximum output is 125W
Good luck .
PCB designed by
beni_iosia2005 [@] yahoo.com
DOWNLOAD EAGLE PCB