We found this circuit in a 1976 documentation. The FET can be BF245 or MPF102 and the power supply need not be symmetrical. The FET in the feedback acts as an automatic gain control.
We found this circuit in an English publication from 1980. It provides a logical output signal when...
This circuit was found in a 1980 documentation. The triac used is of the TIC226D type which in the...
The integrated circuit used is a dual 555 CMOS. The circuit is from an English documentation and...