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Q & A: Zapping with too many volts

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Most recent answer: 10/22/2007
Q:
I was wondering what would happen to a device that takes a 1.5 voltage battery if i used an AC adapter that puts out 3 volts. Thanks.
- Chris (age 17)
Heritage School, IL
A:
Hi Chris,

That depends a lot on what kind of device it is! If it's a flashlight, it may put out four times the energy in heat and light (or perhaps somewhat less, as the resistance of a light bulb goes up a bit when it gets hot). (Of course, the bulb may quickly burn out.) If it's a DC motors with brushes, maybe it will just spin faster. If it is a delicate electronic instrument, you could permanently damage it by applying 3 Volts when only 1.5 Volts are expected. Many commercial electronic devices are protected against small mistakes like this (but maybe not against big ones like plugging it directly into the wall socket, which could cause a fire or make something pop out of its socket fast enough to injure you).

Tom

(published on 10/22/2007)

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