This is one of the channels of an amplifier suggested by Westinghouse in 1970s documentation. The circuit uses components from the era and no information about the transformer is given.
This circuit emits a sound at regular intervals to prevent you from falling asleep, for example. It...
November 2016 - Texas Instruments' new TLV8802 nano-power operational amplifiers for wireless...
The circuit presented is from 1994 and can be implemented with more modern equivalent components. We...