Power Supply With Digital Volt-Amp Panel Meter

This variable DC power supply project converts high-voltage alternating current into a stable, adjustable direct current output monitored in real time. The circuit begins with a 230V AC primary to 15V 1A secondary transformer (X1), which steps down the high mains voltage to a safer AC level. This stepped-down AC is then fed into a bridge rectifier formed by diodes D1 through D4, converting the alternating current into pulsating DC. Capacitor C1 smooths this pulsating DC into a raw DC voltage bus. The core regulation is handled by the LM317 adjustable voltage regulator (IC1). By adjusting the 22-kilo-ohm variable resistor (VR1) in conjunction with the 680-ohm resistor (R2) connected to its adjustment pin, the output voltage can be precisely controlled across a continuous range. Additional capacitors C2 and C3 improve transient response and output stability. Diode D5 provides reverse-bias protection for the regulator. The output feeds a connected load while simultaneously powering a digital panel meter (DPM1), which provides real-time readouts of both the delivered voltage and current. Finally, LED1 serves as a visual indicator to show when the power supply is active.

Benchtop testing, laboratory experiments, electronics prototyping, and powering various DC electronic circuits requiring adjustable voltage and current monitoring.