Suggested by Philips in 1966 documentation, this limiter can be found elsewhere on this website. The circuit is for 7 V, but can be changed to other voltages, depending on the zener diodes.
This light sensor shield, with operational and TTL compatible output or microcontroller was found...
This circuit is from a 1980s Motorola documentation. The circuit can be made with modern...
The number of pulses produced by this circuit depends on the switch pressed. The circuit is from...