This 555 IC circuit was found in June 1984 Radio Electronics magazine. This circuit detects a change in the signal and can power a relay or other warning system.
This configuration makes use of currently uncommon components. In fact, we found it in...
This 1 kHz oscillator was found in the February 1970 issue of Radio Electronics magazine. It uses...
This circuit was found in Motorola documentation from 1968. Transistors can be modern equivalents, just...