December 4, 2013 Leave a comment
What is it?
These are small single-voltage regulators based on LM317-type regulators suitable for many supporting applications. The output voltage set via two resistors but not variable afterwards.
How big are the boards?
The smaller board measures 1.975×1.425″ (app. 50x36mm) while the bigger board measures 1.975″ (app. 50mm) square.
What is the status of the boards?
The boards are in version 1.1. I have built both version 1.0 and version 1.1 of both and they work fine.
Does it use any special/expensive/hard-to-find parts?
Not really. You can go overboard with low-noise/low-drop regulators and audiophile caps if you feel like it, but there’s no need for that.
Anything else I need to know?
- The protection diodes (which are not required but still recommended) are MELF-style 1N400x mounted on the bottom of the board. The resistor for the LED is an SMD-type as well.
- The heat sinks are Fischer SK104 (or equivalent) for the small board and Fischer SK129 (or equivalent) for the larger board.
- Note that although you can get regulators rated at several amps, the DIP-packaged rectifier bridges are difficult to find in more than 1A ratings (although 2A exist).
Download design files here
For a small spreadsheet that can be used to calculate resistor values, output voltages etc. for the regulators, see the “download” page (or google to find an online calculator)
Always check the manufacturer’s datasheet for the regulators of your choice to confirm all bypass recommendations, parameters and load conditions. This is especially important if you decide to use low-dropout (LDO) or low-noise types.
Note: Always read the “intro post” for additional important information about my designs.