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 serves as the basis for applications such as timers and alarms, being its base two of...
This transmitter operates in the 80-meter range, around 3.5 MHz, with an exact frequency value...
With the circuit shown in the figure, it is possible to connect or disconnect a load controlled by the...