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This article describes a spreadsheet program for designing low-voltage power supplies using common IC three-terminal regulators. The spreadsheets are in standard Excel format, and should work in just about any spreadsheet program. Each file has two main pages: one for use with common variable-output regulator chips, the other for fixed-output devices. This article was published in audioXpress, March 2010.

In this amazing project by Gregory L. Charvat, two pre-amplifiers are used with a battery powered high voltage supply. The high voltage supply works by creating a square wave with a 555 timer. The square wave is fed into a small audio power op-amp. The output of this op-amp is back-fed into the secondary of an audio output transformer, generating high voltage AC 170V at 40 kHz. This signal is rectified, filtered, and regulated in a conventional sense. The entire system runs on 8 AA batteries and should operate for approximately 4 hours continuously. This article was originally published in audioXpress, March 2010.