Found on a 1965 Radio Electronics, this circuit fires a signal xenon lamp applied to the SCR from an external trigger. The pulse transformer generates high voltage for flash triggering.
This sonic switch, sound relay or simply vox uses a medium impedance speaker as a microphone. The...
This circuit is an impedance adapter. The circuit is from a Radio Electronics from April 1966. The...
This circuit using components that are still common in our market was found in a 1987...