Found in Signalite documentation from the 1960s, this circuit generates ladder pulses. The circuit generates 3 steps and below 40 V of power, it works as a frequency divider.
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....