This simple injector and signal follower employs a high impedance headset. Transistors can be of general use. The circuit is from old American documentation.
Here we show how two 4017s can be cascaded to count above 10. The circuits are driven by a square...
The circuit in the figure represents a typical application of a phototransistor exciting a relay...
This circuit, in fact, what it does is a reactivation of the batteries through a brief pulsating...