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 power supply was originally created for the CB16760E (Loudness System) but can be used in any...
Found in 1980s Electronic Engineering, this circuit uses common phototransistors as sensors. The...
This simple, unregulated power supply with an approximate 6 V output voltage can supply currents up to...