This circuit with the CA3059 was found in the July 1995 Elexctronics Now magazine. The signal must be DC, and the circuit is not isolated from the mains.
Originally designed to analyze the shape of light pulses from a flash for photographic...
This RCA circuit has current limitation. The circuit is from an ancient American documentation making...
This useful power supply was found in an 1985 Italian publication, but can still be assembled...