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 makes use of a transconductance operational amplifier. It generates signals with TTL...
This circuit uses na Unijunction Transistor (UJT) to produce a modulation tone for several...
This circuit was found in General Electric documentation from the 1980s. The circuit uses couplers...