We found this circuit in a 1996 publication. The circuit uses components that are still common. The timing depends on C1, which can be changed, and the triac can be of any type.
We obtained this circuit from an old Argentine magazine. The circuit originally uses germanium...
We found this circuit in an old English publication. The sensor is a common LDR. and the...
This circuit is from an 80's component manual. The components are from the time, but the circuit...