This contact or reed switch actuation was found in a 1964 Electronic Design. The circuit can be used with sensors and the triac is load dependent.
We found this 555 integrated-circuit tester in an old Electronics Hobbyst from 1977. The circuit is...
This TTL circuit with the 7493 makes the binary count of the pulses sent by a flip-flop with the...
This tone recognizer circuit that relies on R5 and C1 was found in the December 1994 issue of...