10A 13.8V Power supply with LM723

The circuit in Figure1 will give us 10 amps with performance that equals or exceeds any commercial unit.
The circuit even has a current limiting feature which is a more reliable system than most commercial units have. This circuit uses the LM723 IC which gives us excellent voltage regulation. The circuit uses 3transistors 2n3055 which must be heat sinked.
Potentiometer R9 allows the tuning of the voltage to 13.8 volts and the resistor network formed by resistors R4 ,R7 controls the current limiting.
The LM723 limits the current when the voltage drop across R5 approaches 0.7 volts. To reduce costs, most commercial units rely on the HFE of the pass transistors to determine the current limiting.

For an extra protection we can use the circuit from Figure 2 who senses when the voltage exceeds 15 volts and causes the zener diode to conduct and the gate of the SCR is turned on and causes the SCR to short which blows the fuse and shuts off the output voltage.


Components

Notation

Value/Description

R1 R2,R3 R4 R5 R6,R7 R8 R9 R10 C1,C2,C3,C4 C5 C6 IC1 Q1 Q2,Q3 S1 F1 3 D1-D4 T1

1.5K ¼Watt Resistor 0.1 Ohm 10 Watt Resistor 270 Ohm ¼ Watt Resistor 680 Ohm ¼Watt Resistor 0.15 Ohm 10 Watt Resistor 2.7K ¼Watt Resistor 1K Potentiometru 3.3K ¼ Watt Resistor 4700µF Electrolytic Capacitor 35 Volt 100pF Ceramic Disk Capacitor 1000µF Electrolytic Capacitor 25 Volt LM723 Regulator de tensiune TIP3055T NPN Transistor (TO-220) 2N3055 NPN Transistor (TO-3) Switch Siguranta Punte redresoare Transformator 18V, 10A