@▷ REGULATED POWER SUPPLY USING 741 AND 2N3055 | Diagram for Schematic


DC regulated power supply using 741 op amp ic and 2n3055 power transistor

DC Regulated power supply Using 741 Op Amp IC And 2N3055 Power Transistor

The voltage regulated power supply provides an adjustable voltage output at a load current up to 1A. The supply has a built-in overload protection.

regulated power supply circuit using 741 op amp  ic and 2n3055 transistor

PARTS LIST R1 6.8kΩ R2 1kΩ R3 10kΩ  Potentiometer R4 22kΩ R5 10kΩ R6 0.6Ω 1W R7 330Ω R8 2.2kΩ 1W C1 2200µF 50v C2 100µF 50v C3 22µF 16v C4 o.1µF 50V D1 3 Amp Diode D2 3 Amp Diode D3 1 Amp Diode D4 6.8V 500mA Zener Diode D5 6.8V 500mA Zener Diode T1 2N1481 or D313 or 2SC1061 T2 2N3055 T3 BC107 IC1 LM741 TR1 SEC 15V, 2AMP

Rectifier diodes D1 and D2 along with capacitor C1 provide the main unregulated supply. D3, C2, R8 and zener diode provide a negative voltage supply for the 741. The non-inverting input terminal of 741 is given a stable voltage by R3 which is the control to set the output. A fraction of the regulated output is fed back via R4 and R5 to the inverting input terminal. The operational amplifier adjusts its output voltage so as to keep the voltage at the input terminals equal. Thus the output gets regulated. The output of 741 is amplified by a compound emitter follower T1 and T2.

All the current flows through R6. If the load current exceeds 1A, the voltage drop across R6 exceeds 0.6 volts and T3 starts conducting. This bypasses the supply to T1 and T2 and the regulating action stops. The output voltage therefore starts falling when the load current exceeds 1A. Any of the output terminals can be grounded to get a positive or a negative voltage with respect to the ground.

power supply, Regulator Diagrams