Found in a 90s Popular Electronics, this sensor operates by infrared reflection. The components are modern, and the phototransistor can be of almost any type.
Found in a 80’s Popular Electronics, this circuit detects the positive peak of a signal providing a...
This circuit found in Radio Electronics can be used in games to produce a random pulse train. The...
IDT ZSSC3230 Capacitive Sensor Signal Conditioner Available from Mouser Electronics stock, this IDT...