Power Supply Module

This is a small power supply module for the hobbyist to use when powering small projects.

I have used a power supply on a half size breadboard for years, but contacts on the breadboard wear out, parts come loose, etc., so I came up with this. This is half the size of a half size breadboard.

The module is powered by a 15 volt DC wall wart power supply, then one can swap out the 78xx voltage regulator on the module for an output of 5, 6, 9, or 12 volts. Male header pins are used for output power. Negative voltages and 3.3 volts is NOT supported with this module.

This project would be great if you need a multiple voltages for various projects you are working on, and would be a great school project for a electronics class.

You should have basic soldering skills and be able to read schematics.

Parts:

Power supply module PCB, the gerber can be found on my Proton drive here, and the PCB can be ordered from PCBWay here.

male header pins, 2.54 1x2 black, OR 1x1 red and 1x1 black

10K 1/4 watt resistor 5%, x1

SR260 Schottky diode, x1

100nf (104) monolithic capacitor, x2

SPDT mini slide switch with 3 pins, x1

6 pin DIP, x1

power jack 5.5x2.1mm, x1

10uF 25v electrolytic capacitor, x2

nylon standoffs 3x6mm, x4, plus 3mm screws, x4

15 VDC power adapter (wall wart), + on center pin

L78xx voltage regulators, 5, 6, 9, or 12 volts, with heatsinks, as needed

Tools:

Schematic

Electrical tape

Soldering iron & solder, plus liquid flux and solder wick if mistakes are made

Flush cutters

Small breadboard, or pin header soldering tool, used for installing the header pins

Multimeter with hook probes

Since there is a low number of parts for this project, assembly is straightforward. You will solder parts in from lowest profile to tallest, and the parts are listed in that order under Supplies as well.

When inserting a part, use a piece of electrical tape to hold the part in place, solder, remove tape, trim leads as needed.

The standoffs keep the module off your work surface.

Functions:

J1, used to supply 15 VDC to the module, center pin is for +.

SW1, turns module on or off.

D2, prevents reverse polarity, a Schottky diode is used for low voltage drop.

C1 and C3, are electrolytic filter capacitors, C1 on input, C3 on output.

C2 and C4, are disc (I use monolithic) filter capacitors, C2 on input, C4 on output.

U1, is a DIP-6 socket, the 78xx regulator will be inserted into pins 1, 2, and 3 (they are marked), which correspond to the lead pinout on the regulator itself.

R1, is a current limiting resistor for D1.

D1, is a 3 mm green LED that is illuminated when power is on.

H1, is the output pins, they are marked + and - if red and black was not used.

For this step you need a multimeter, set to measure DC, mine is set at 20 volts, and you need hook probes.

Insert a 78xx regulator (5, 6, 9, or 12 volts only), with or without heatsink is fine for this test, into U1 in the pins marked 1, 2, and 3. The front of the regulator should be facing the 1, 2, and 3, and the tab should be facing the edge of the module.

Connect the hook probes to the + and - pins of H1.

Turn on SW1, D1 should illuminate, and voltage on the meter should correspond to the regulator you inserted in U1.

This little module is kept on my workbench and is used often. Enjoy.

I may make a revision to include being able to use a 3.3 volt regulator, and adding more output pins, but keeping the same size PCB.