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 high sensitivity receiver of 30 nW was found in documentation from the 1980s. Integrated...
This circuit is an alternative to using Darlington power transistors in the previous amplifier. The...
The trigger element of this circuit is a neon lamp. The SCR admits an equivalent. We found it in...