12v 5 Amp Power Supply Circuit [exclusive] -

Consider adding a Zener diode and an SCR (Silicon Controlled Rectifier) at the output. If the pass transistor fails (which usually results in a "short" that sends the full 18V+ to your device), the crowbar circuit will blow the fuse to protect your load.

Building a high-current supply requires built-in safeguards: 12v 5 amp power supply circuit

Mount the transformer and PCB inside a ventilated enclosure. Consider adding a Zener diode and an SCR

A single-unit bridge rectifier rated for 10A–25A (e.g., GBPC2510 or KBPC3510) to provide a safety margin. Filter Capacitors: a 5A fuse for the output

Large heatsink for the transistor and regulator, a 5A fuse for the output, and a 1A fuse for the AC input. 2. Core Circuit Design The circuit follows four main stages of power conversion: 5A Variable Linear Power Supply - Instructables