The indicator shows when the mains is present at its output by a continuous glow of a neon bulb, La1, and when the fuse is blown by flashing of the neon bulb. When the fuse is intact, capacitor C2 ...
Looking for a mains switch inthe dark is easier if the switchcontains a built-in neon or filamentminiature lamp. Adding a small indicatorto any mains switch is helpful. It iseven better if the ...