We found this circuit in a 1968 General Electric publication. The circuit uses an SCR of the time, but any modern equivalent can be used. The relay must have contacts that support the horn current.
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This countdown electromagnetic ring launcher was found in an Electronic Hobbyst Handbook from...
This TTL circuit was found in an American documentation from the 80s. The components are common in the...