Found in the August 1993 Electronics Now magazine, this circuit employs two symmetrical source 741 op-amps. The output is fed to a true RMS measurement circuit.
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...