This sound relay or Vox was found in 70s RCA documentation. SCRs can be common types today and transistor a BC558. The circuit is for the 110V power grid.
This circuit is another practical idea for places where they still receive signals from analog TV. The...
This setting appears elsewhere in this site from other sources or projects. Instead of the lamp...
This strobe light circuit with xenon lamp was found in a 1995 documentation. The circuit is...