fyemane / dc-power-supply-project

Designed and built a 30 V DC linear bench power supply

DC-power-supply-project

March 2022 - May 2022

Designed and built a 30V DC linear bench power supply

A power supply is a great tool for all electrical enthusiasts. My BCIT electrical engineering program included a 4-month course ELEX 1112: Engineering Tools, and a 4-week course ELEX 1102: Electronics Fabrication Tools and Techniques, in which I designed and built a DC linear bench power supply.

My bench power supply!

I learned how to use AutoCAD 2022 to design the body chassis, Solidworks PCB to design the PCB electrical schematic, and Altium Designer to manually route and verify the PCB component layout. I also learned how to use hand and power tools to solder SHT and TH components onto a PCB, wire the PCB with the internal circuitry, and assemble the metal chassis together to complete the project.

The 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 +15VDC (variable). The rated current at each output is 1A.

Parts list (Electrical)

Ref Des	Value/PN	Description	Pkg	Qty
C1,C2	3300uF, 20%	25V, Al electrolytic	Radial	2
C3,C5	0.1uF, 20%	50V, Al electrolytic	Radial	2
C4,C6	1uF, 20%	50V, Al electrolytic	Radial	2
C7	2.2uF, 20%	50V, Al electrolytic	Radial	1
D1,D2,D3,D4	1N4005	1A, 600V, General purpose	D0-41	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, 18AWG/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, Fixed, Variable	TO220-3	1
U3	7915	Regulator, 1A, Fixed, 15V	TO220-3	1

Diagrams

Reference designs were provided by BCIT. I also created a 3D CAD model of the power supply chassis.

(1) (2)

(1) PCB artwork (2) PCB component locator

(3) (4)

(3) Schematic diagram (4) Interconnect diagram

(5) (6)

(5) Plan view (6) An X-ray perspective view of 3D chassis using AutoCAD 2022