Circuit knowledge

Build a Power Supply Variable 1.3V - 12.2V 1A Circuit Diagram. In this schema R2 to set the output voltage. The maximum current is determined by R3, over-current protection schema inside the LM723 to detect the voltage on R3, if it reaches 0.65 V, the voltage output will be off her. So the current through R3 can not exceed 0.65 / R3 although output short-schema in his.

C3 and C4 are ceramic capacitors, as much as possible directly soldered to the PCB, this is because the LM723 is prone to oscillation that is not cool.

LM723 works with 9.5V input voltage to 40 V DC and the LM723 can generate its own current of 150mA when the output voltage is not more than 6-7V under input voltage.

Output (value estimated):

Vmin = (R4 + R5) / (R5 * 1.3)

Vmax = (7.15 / R5) * (R4 + R5)

Imax = 0.65/R3

Max. Power on R3: 0.42/R3

Min. DC Input Voltage (pin 12 to pin 7): Vmax + 5

B1 40V/2.5A

C1 2200uF (3300uF even better)

C2 4.7uF

C3 100nF

C4 1NF

C5 330nF

C6 100uF

Green LED D1

D2 1N4003

F1 0.2A F

F2 2A M

IC1 LM723 (in a DIL14 plastic package)

R1 1k

R2 Pot. 5k

R3 0.56R/2W

R4 3.3k

R5 4.7k

S1 250V/1A

T1 2N3055 on a heatsink 5K / W

TR1 220V/17V/1.5