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 simulates an inductor. Or operational amplifier of old type, but a configuration is...
We found this circuit in a 1967 Electronic Design. The circuit uses contemporary transistors that...
To control relays safely with double insulation, we suggest the circuit in the figure. The optical...