We found this transistorized circuit in a 1985 documentation. The circuit can operate with voltages from 9 to 12 V and the adjustment of the operating point or input sensitivity is done in P1.
This circuit is from the 1983 Intersil Databook. This is a configuration that is still used today...
This shield circuit, from a documentation from the 70s, employs an optocoupler with two SCRs to...
We found this circuit in the 1982 SGS Linear Integrated Circuits manual. The integrated circuit used...