The selected circuit was found in GE's 1977 semiconductor manual. 3N84 is a controlled silicon switch and SCRs support equivalents. The transistor can be a BC558, depending on the supply voltage.
Using junction FETs, a configurable configuration is achieved for very low frequencies. FETs can...
This is a conventional circuit with triac but no diac which would be nice in place of R2. In the...
This simple teaching circuit uses 5 transistors in a monophonic organ version whose notes are...