The
L.E.D. Close-Up.
When
a small current flows through an L.E.D. (normally
about 20-30 milliamps) it will light up. Unlike an ordinary bulb,
its two connections ( + and -) must be connected correctly to
the power source for it to work.
The
two different connections to the L.E.D. are :
1, The Anode (+)
2,
The Cathode (-).
These
can be identified by looking for either the long (+) or
short (-) legs. The flattened edge of the led is always nearest
to the Cathode (-). Please look carefully at the image above
to see this.
Getting
it working
L.E.D.s are semiconductors and most of them cannot work
safely in a circuit on their own. This is because they allow too
much current to flow - unlike the light bulb that takes only the
current it needs to work.
To
protect the L.E.D., it is necessary to use an electronic
component called a resistor. This is connected in series
with it.
Please go on to the next link
to find out about this.
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