logajan@ns.UUCP (John Logajan) (03/17/89)
Harold Wong writes: > I have a line tester consisting of a screwdriver (the probe) connected to a > neon bulb connected to a metal cap on the end which I'm suppose to touch. > How does this work? You are a capacitor. Current (very tiny amount need to light neon bulb) flows from the line through a resistor, thru the gas in the bulb, into you. The current then reverses and flows the other way. It does this 60(50 euro) times a second. If it was DC you would quickly charge to line potential and the current would drop to leakage amounts. This might or might not be enough to keep the bulb glowing -- I don't know. Leakage can be through several mechanisms. Most significantly, water in clothing in contact with other objects, and evaporated water to "broadcast" your charge into the surrounding air. -- - John M. Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 - - ...rutgers!umn-cs!ns!logajan / logajan@ns.network.com / john@logajan.mn.org -