This 80's documentation circuit includes an amplifier of the era. Used integrated circuits are uncommon today but can be used equivalents.
A touch in this circuit turns-on the lamp or the relay. Power supply is according the lamp or...
June 2017 - The new ROHM Low Dropout Voltage Regulators (LDOs) for 3.3 V or 5.0 V high accuracy...
The purpose of this circuit, which we find in a 1975 radio amateur publication, is to measure the...