R. A. Penfold

How to Use Oscilloscopes and Other Test Equipment

By R. A. Penfold, Penfold, R. A.

High Power Audio Amplifier Construction (BP S.)

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50 Complementary Metal-oxide Semiconductor IC Projects

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Using Flash MX: BP527

By R. A. Penfold

Audio Amplifier Construction

By R. A. Penfold

Practical Alarm Projects

By R. A. Penfold