This circuit, found in a 1977 documentation, indicates when the grid voltage goes through zero. Under these conditions, it produces an output pulse whose duration depends on the capacitor.
The circuit we show is part of an article that taught its complete assembly. The article is from...
Found in American documentation from the 90s, this circuit has a timing system for activating the...
This circuit was obtained in a 90s Popular Electronics. It generates a 10 Hz sinusoidal signal...