Found in American documentation from the 90s, this circuit can be applied to other operational ones. We found it in an EDN of the time. Next to the diagram is the response curve.
This circuit triggers a remote doorbell when the phone rings. The circuit is for the 110 V mains...
This circuit uses the 741 Operational Amplifier to drive two LEDs. The LEDs indicate the signal of...
This dimmer was found in a 1980 publication. The Triac can be any of the TIC series and the...