Originally suitable for photography applications, this circuit from a Popular Electronics from the 90s can also be used to time plate baths. The components are common, and the sensor is remote.
) The integrated circuit used in this control is uncommon today and the maximum current obtained allows...
This sample and hold circuit is from a 1969’s documentation. However, it can be built with modern...
Suitable for general use and alarms, this Hartley oscillator circuit from a 1960's Gernsback...