We found this circuit in a publication by General Electric in the 1980s. The transistors and the PUT are from that time. The control is done by a tachometer based on an optical coupler.
This is the factory setting (National Semiconductor) of the TDA2006 as an audio amplifier. The...
This circuit can be used as an input shield for microcontrollers or other TTL circuits. The power...
This circuit can be used to couple signal sources or low intensity transducers to microcontrollers (Shield)....