The time of this timer depends on C1. The circuit was found in the July 1994 Electronics Now magazine. The supply voltage depends on the relay and can go up to 12 V.
This circuit from a National Semiconductor manual from the 1980s shows how to use the LM388, a...
This is a circuit with a new (at the time) component released by Raytheon in 1965. The circuit uses a...
Suggested by General Electric in a 1970 documentation, this circuit makes use of some components of...