This signal injector and tracer (follower) was found in an old American documentation. The transistors can be general use and power is made with one or two common cells.
This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the...
This circuit produces low frequency sinusoidal signals. The circuit is a phase shift oscillator...
This variation of the previous circuit produces a pulsating sound when the sensor is activated. The...