We found this circuit in the 1983 Radio Electronics Special projects magazine. The components are common, and the circuit drives a relay. The power supply must be isolated.
We found this test circuit in a March 1967 Radio Electronics. The circuit uses a zener-regulated supply and...
We found this circuit in a 1995 publication. It applies to transceivers in the citizen's range (11...
The figure shows how to associate flip-flops in a shift register to obtain a lower frequency...