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 device can be used as a proximity arm, touch sensor or electronic bell. When connected to a...
This circuit is from the component's own manual, but it applies to others in the same family. The...
This circuit was found in a 90s Popular Electronics. The circuit uses several relays in order to...