This circuit was obtained from a 1970s RCA. The circuit uses LDRs as sensors. The resistors depend on the A / D converter used. The circuit can be used as a shield.
This circuit increases the sensitivity of a multimeter in the measure of small alternating...
This circuit triggers a buzzer or other warning device when the light falling on the sensor is cut...
This circuit open and close the relay in intervals adjusted by the potentiometers. The capacitors...