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DiscoverCircuits.com -- Hobby Corner
Last Updated on:
Tuesday, April 01, 2014 04:33 AM
Hobby Circuits' Category
List
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More
Lamp Controls
Switches |
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12v Light/Dark Switch |
Often, for certain low voltage lighting systems; you would like to turn off the lights
during the bright light of the day. Most commercial day/night switches are
designed for AC lighting. This hobby circuit below was designed for a 12v DC
system. But, it could be modified for other voltage as well. It uses an
inexpensive phototransistor as the light detector. An n-channel FET is used to
switch power to the lights. A transistor circuit is included to provide some
hysteresis. This keeps the circuit from fluttering the light during the
transition from day to night and night to day. It is recommended that a plastic
tube be placed over the transistor to prevent it from being illuminated by the lights
it is controlling. By selecting the appropriate power FET, the circuit could
control over 100 watts worth of 12v lighting. (July 22, 2008) |
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Click
on Drawing Below to view PDF version of Schematic |
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