Needed a bench PSU for motor and amp testing but commercial ones are way too expensive for my budget right now, so decided to hack one together from scraps.

Base is an old Frontech 45A ATX unit I had lying around. For the enclosure I literally used thick cardboard reinforced with insulated tape on the borders and cut pieces of PVC pipe for corner protection and structure (actually holds up surprisingly solid lol).

Features/Rails:

4 independent channels

Buck converter channel for stepping down

Boost converter stepping up to 36V max

5V / 3.3V selectable rail via a 6-pin switch

Dedicated -12V rail (specifically pulled this out for dual supply audio op-amp testing)

Dual display volt/amp meter on front

10k pots for fine voltage tuning

4 pairs of female banana jacks

Tested it under load with 12V and 24V high-torque motors, long LED strips, and some basic circuits. Voltage stays stable across the rails though I haven't pushed max amps on the boost module for long sessions yet to check thermals.

Documented the wiring, pinouts, and quick load test here if anyone wants to build something similar on zero budget

Any suggestions on improving cooling inside a cardboard housing without compromising structural rigidity?

Built a 4-channel bench power supply out of junk and an old PC PSU for under $10