Suggested by Raytheon in 1967 documentation this circuit uses a lightbulb and LDR optical coupler of the time. The transistor determines the maximum current.
The circuit shown in the figure is sensitive to light. Its frequency is determined by the light...
For a maximum current of 50 mA the capacitor must be from 470 nF to 250 V if the grid is 110 V and...
In its first version this article was written in Portuguese for a Brazilian magazine and...