This circuit was obtained from an American 1980s documentation. The frequency depends on the crystal and the circuit may be a PNP that reaches the generated frequency.
This circuit controls a relay in a bistable way by touching the sensors type NF (CH3) and NO...
This circuit produces modulated tones in a loudspeaker. The effects can be adjusted by the...
This is a simulation of a Relaxation Oscillator using a programmable unijunction transistor (PUT). The...