Found in a 73 magazine for radio amateurs of the 90s, this circuit provides a 2 kV voltage with 7.5 mA of current for HeNe laser.
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...