This photoelectric sensor that triggers a relay was found in an English book from 1989. The transistor is a general-purpose type, and the integrated circuit consists of an operational amplifier.
Found on Popular Electronics this circuit has variations found throughout this site and section....
This effect for guitar was found in an English magazine from 1978. The transistors can be the most...
This circuit was found in a 90s Popular Electronics. It is possible to analyze the voltages of an...