Found in a 90s Popular Electronics, this circuit excites a 40 kHz ultrasonic transducer. The transistor can be a BD135 or other medium power.
When the sensor X1 is opened, the relay is energized. When waiting, the current drained is very...
This circuit can also use other series operational amplifiers such as MC33172, MC33174, MC35171,...
This circuit was originally designed to power the CB18698's MSX interface, but it is suitable for...