This circuit is from a 90s documentation. It has a hysteresis and uses a light sensing bridge. The circuit generates a 1000 Hz modulated 10 Hz signal. The signal must be applied to an amplifier.
The purpose of this 1967 Philips circuit is to produce a rectangular signal from a sharp pulse....
This very low current circuit with the ICM7860 was found in the April 1995 Electronics Now...
We found this circuit in an old American documentation. The operational amplifier is not common...