This long interval timer was found in the September 1976 issue of Radio Electronics magazine. The output can be used to control a relay. The circuit achieves timings of up to 14 hours.
This circuit with only one transistor was found in Japanese documentation from the 1960s. The...
This circuit uses a common multimeter on the voltage scale. The calibration of the scale should be...
This interface shield circuit is from the 1983 Intersil Databook. The components used are uncommon...