This 1968 Texas Instruments circuit uses diacs of the era. SCRs can be modern equivalents according to the controlled load.
When the sensor connected to points A and B is activated, removing the ground from the base of Q1...
This oscillator was found in the 1994 National Instruments Linear Applications Handbook. The...
With the circuit shown in the figure, the frequency of a 5 MHz oscillator controlled by crystal can...