This circuit was obtained from the Encyclopedia of Electronic Circuits volume 5 of 1995. The circuit uses the 4001 CMOS to obtain hysteresis in the sensor feedback.
This circuit was found in a recent English publication, making use of a power transistor that...
We find this oscillator in a 1980s documentation. The frequency depends on the crystal and the...
With this circuit it is possible to receive and send audio signals simultaneously over the same...