Found in a 1965’s Electronic Design, this circuit operates with a voltage of 1.5 V. The relay can be of a reed relay or other type.
We found this simple alarm circuit in a 1986 documentation. The circuit uses sensors of the NA...
This sound relay or Vox was found in 70s RCA documentation. SCRs can be common types today and...
Placed near a common receiver, this oscillator is intended to generate a beating signal to receive...