This power supply module provides an unregulated +/-20VDC as well as a regulated +/-16VDC supply.
It was designed to allow the unregulated dual rail to power a small power amplifier and teh regulated dual rail for the preamp and other analogue circuitry, and used in the mono balance monitor project.
The transformer input to this module is 15-0-15 (ie 30V CT). A toroid is recommended and needs to be sized according to the unregulated rail requirements.
I used a 50VA toroid that I had on hand, but anything that fits from 50VA upwards should do.
The module regulates the 20VAC rail using LM317/LM337 pair, fixed to a +/-16V output with appropriate resistors. The regulators will need insulation from the heatsink using the appropriate mounting and insulation kits.
|PSU-14 Circuit (pdf)||PSU-14 BOM (pdf)||LM317 Data Sheet|
|PSU-14 PCB (pdf)||LM337 Data Sheet|
PSU-14 Power Supply Module