This circuit operates at a voltage of 1.3 V from a single mercury cell. We found in an old documentation and for the components used the frequency is 500 kHz.
We find this circuit in a 1973 technical documentation. Common transistors may be BC548 and FET or...
An interesting type of sensor for specific applications is the sensor formed by piezoelectric...
This circuit assumes that a pulse produced by S1 has a constant duration determined by R1 and C1....