We found this circuit for vocal effects in the September 1990 issue of Radio Electronics magazine. The circuit works with signals from two inputs of a stereo system.
This circuit is from a documentation from the 60s. The circuit can be built with transistors like...
Found in a 1966 General Electric documentation, this dimmer should only be used with incandescent...
To control relays safely with double insulation, we suggest the circuit in the figure. The optical...