We found the circuit of this Japanese transistorized commercial receiver in a documentation from the 1960s. It is a radio for the medium wave range with 6 transistors and 9 V power.
This circuit can be used in tone-modulated optical remote controls or as an optical transmitter for...
This circuit sources a Constant current to a load. The current is determined by R2. In the...
This sound relay or Vox was found in 70s RCA documentation. SCRs can be common types today and...