This kit allows you to build a very simple breadboard power supply that takes power from a DC wall wart and outputs a selectable 5V or 3.3V regulated voltage. The 0.1" headers can be mounted on the bottom of the PCB for simple insertion into a breadboard. Pins labeled VCC and GND plug directly into the power lines. Another pair of pins has no electrical connection but they help support the PCB in a breadboard.
There are two pins available within the barrel jack footprint. Any stripped +/- DC supply can be connected instead of the barrel connector. The board has both an On/Off switch and a Voltage Select switch (3.3V/5V).
This comes as a bag of parts and is easily assembled if you can follow the silkscreen indicators and have beginning experience with a soldering iron. The parts list below indicates the color bands for each resistor type.
The picture below shows an example of the kit fully assembled with a power supply lead connected and the board plugged into a typical breadboard incorrectly. The orientation actually should be 180 degrees opposite of what's shown in the picture, so that VCC is on the red side and GND is on the blue side.
Also note that in order to mount the board as shown, you'll need a breadboard that has its power lines aligned with the prototyping area — many do not. The breadboard offered in the options below has the alignment.
Voltage Regulator Board Kit Contents
- DC Barrel Connector (2.1mm center positive)
- TO-220 Voltage Regulator (LM317 1.5A max current)
- 1N4004 Reverse Protection Diode
- 100uF 25V Capacitor
- 10uF 25V Capacitor
- 0.1uF 50V Capacitor
- Red Power LED — High Brightness (don't look right at it when you apply power!)
- Two SPDT Slide Switches
- Four 0.1" Header Pins
- Two 330Ω Resistors, 1/6W (Orange, Orange, Brown)
- 390Ω Resistor, 1/6W (Orange, White, Brown)
- 240Ω Resistor, 1/6W (Red, Yellow, Brown)
- Bare PCB with Silkscreen Indicators, 1.25 × 1.25 inches
- PTC resettable fuse
Power Input Consideration Make sure to supply enough input voltage for the LM317 regulator. For example, a 4.5V or 5V input will not be enough to produce a 3.3V output. A 9V power supply will be fine for both 3.3V and 5V modes. You should be able to use a 7.5V input for 3.3V mode, but that may only barely be enough for 5V mode (possible instability). A 6V input likewise might only just be enough for 3.3V mode but may not be completely reliable.
Voltage Regulator Board Kit Resources
Optional Recommended Products for this Item