Low, High Voltage and Electronics
Country: United States
Date: Spring 2010
For any home appliance or electronics, let us say a
television or refrigerator, what would be the effect if we provide
under-voltage? What would be the effect if we provide over-voltage?
That is a good question. This is what I found experimentally for
undervoltage (125V ---> 100V):
A compact fluorescent lamp will draw the same current, but be dimmer.
An ordinary AC motor driving a pump will draw more current and rotate slower.
A normal fluorescent lamp will draw less current, less power, and be dimmer.
A sophisticated motorized polishing machine will operate the same,
but consume less power.
An LCD computer monitor will work the same, draw the same power,
with current increasing proportionally.
There is one rule that always works: simple restive loads (like
incandescent lamps or toasters) will be dimmer and draw less current and power.
For devices, circuits, and machinery that are not simple, the effect
of undervoltage depends on the details of the circuit and
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Update: June 2012