This circuit allows you to simulate an analog telephone line for the repair and testing of devices. The circuit is from 1994 and all the components used are common.
This circuit was obtained from a 1965 Radio Electronics. The semiconductors used admit modern...
In the bridged configuration the TDA2002 amplifier can supply 30 W of power at a load of 4 ohms...
This circuit converts a high voltage into a frequency using an optical coupler. The transistor can be 2N2646...