This circuit was found in an Electronics World of 1966. It has a range of 5 to 25 000 Hz at 1 dB and the diagram includes the power supply.
This is the receiver circuit for the previous transmitter (CB19628E). The receiver is an infrared...
This circuit was found in old American documentation. Transistor is general purpose and coil rated...
Found in English documentation, this touch sensitive switch must be powered by an isolation...