A bench power supply is an essential tool for all electronics hobbyists. Building one is the right of passage for every electrical engineer. My BCIT program included a 4-week course ELEX 1102: Electronics Fabrication Tools and Techniques, in which we built a very basic bench power supply.
We learned soldering skills in this course. We also learned how to use Altium Designer to design our own PCBs. In another course I learned how to use AutoCAD and designed the body for this power supply (reference design provided by BCIT).
The DC Power Supply provides three DC voltage outputs when powered by a 120VAC 60Hz source. The rated DC output voltages are +5VDC (fixed), -15VDC (fixed), and +20VDC (variable). The rated current at each output is 1A.
BOM (Electrical)
| Ref Des | Value/PN | Description | Pkg | Qty |
|---|---|---|---|---|
| C1,C2 | 3300uF, 20% | 25V, AI electrolytic | Radial | 2 |
| C3, C5 | 0.1uF, 20% | 50V, AI electrolytic | Radial | 2 |
| C4,C6 | 1uF, 20% | 50V, AI electrolytic | Radial | 2 |
| C7 | 2.2uF, 20% | 50V, AI electrolytic | Radial | 1 |
| D1,D2,D3,D4 | 1N4005 | 1A, 600V, General Purpose | DO-41 | 4 |
| D5 | Pilot light, LED, Red | 1 | ||
| F1 | 375mA, 250V | Cartridge, Glass, Time delay | 1 | |
| J1 | Banana jack, Red, Nut | 1 | ||
| J2 | Banana jack, White, Nut | 1 | ||
| J3 | Banana jack, Violet, Nut | 1 | ||
| J4 | Banana jack, Black, Nut | 1 | ||
| P1 | 125V, 10A | 1.8m, 18 AWG/3C Grey | 1 | |
| R1 | 10R, 5% | 10W | Axial | 1 |
| R2,R4 | 390R, 5% | 1/4W | Axial | 2 |
| R3 | 5K, 10% | 1/2W, Linear | 1 | |
| S1 | 120V, 5A | SPST, Round rocker, Dot | 1 | |
| T1 | 33VCT/1A | 33V, Center tapped, 1A | 1 | |
| U1 | 7805 | Regulator, 1A, Fixed, 5V | TO220-3 | 1 |
| U2 | 317 | Regulator, 1.5A, Variable | TO220-3 | 1 |
| U3 | 7915 | Regulator, 1A, Fixed, 15V | TO-220-3 | 1 |
Schematic diagram, interconnect diagram, and body CAD...
