This circuit activates a recorder from the signal obtained from a telephone line in the service. It is used to make automatic call recordings.
The circuit that gave rise to this configuration is from 1978. In the original publication are...
Found ina 1970 American documentation this fast-reading circuit uses a photodiode. Transistors...
Found in an 1868 Mullard documentation this circuit has a dynamic range of 10 Hz to 25,000 Hz....