This circuit is the receiver for the previous transmitter modulated by an audio signal. The transducer is a ceramic capsule, in which case the circuit becomes ideal for telegraphic transmissions.
Found in Ferranti's 1968 documentation, this circuit uses a Darlington photo transistor to drive a...
Found in documentation from the 70s, this circuit uses components from that time. Some of these...
This circuit monitors the state of a 12 V battery and can be used directly with one, or even in a...