This detector with ultra-low deviation was found in an American documentation from the 90s. Operational amplifiers are from that time. The power supply must be symmetrical.
This circuit was found in the September 1974 issue of Radio Electronics magazine. The circuit uses...
This circuit was found in the December 1983 issue of Radio Electronics magazine. The sensor is an...
We found this circuit in a 1975 publication. The circuit can be made with more modern equivalent...