Project / Electronics
A custom bench supply with a variable 0.5–27 V channel and regulated +5 V channel, designed, simulated, assembled, and packaged for lab use.
LM317TLM7805BD1392N3055Proteus
The project converts isolated transformer AC to stable DC outputs for laboratory electronics. A variable channel combines bridge rectification, 4700 μF filtering, LM317T regulation, and a transistor current-boost stage; a separate LM7805 stage provides fixed +5 V.
The variable channel uses a center-tapped 12-0-12 V transformer and a full bridge rectifier. Its practical output range is 0.5–27 V. Parallel 2N3055 pass transistors and 1 Ω emitter resistors improve current sharing and thermal stability.
The fixed channel starts from 12 Vrms, smooths the rectified voltage with a 4700 μF capacitor, and regulates it to +5 V at 0.5 A. Heat sinks support safe linear-regulator operation.
After simulation and breadboard testing, the supply was packaged in a custom molded PVC enclosure. The front panel includes banana terminals, USB outputs, controls, a voltmeter/ammeter module, ventilation, and a carry handle.
