Found in a 90s Linear Technology documentation, this circuit is intended for powering cold cathode fluorescent lamps. The circuit has an input voltage from 4.5 to 20 V.
This circuit has the intensity of the signals controlled by the light that falls on the sensor....
The purpose of the diode in this oscillator circuit is to limit the amplitude of the output...
We found this ladder-shaped signal generator circuit in Radio Electronics magazine from August 1966....