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LDRs or Light Dependent Resistors
are very useful especially in light/dark sensor circuits. Normally
the resistance
of an LDR is very high, sometimes
as high as 1000 000 ohms,
but when they are illuminated with
light resistance drops dramatically.
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LDRs or Light Dependent Resistors are very useful especially in
light/dark sensor circuits. Normally the resistance of an LDR is
very high, sometimes as high as 1000 000 ohms, but when they are
illuminated with light resistance drops dramatically.
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The animation opposite shows
that when the torch is turned on, the resistance of the LDR falls,
allowing current to pass through it.
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Circuit Wizard software has
been used to display, the range of values of a ORP12, LDR
.
When a light level of 1000 lux (bright light) is directed towards
it, the resistance is 400R (ohms).
When a light level of 10 lux (very low light level) is directed
towards it, the resistance has risen dramatically
to 10.43M (10430000
ohms).
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