This circuit was published in an article in Radio Electronics magazine in October 1988. It uses components that are still common today, except for the sensor, which is a special type from that time.
We find this circuit in 1975 documentation. The circuit can be used with other operational...
This circuit is from Popular Electronics from the 90s. The integrated circuit is not very common...
We have other circuits like this on the website. This is from a 1967 Electronics World. The Triac...