Quote:
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Originally Posted by Vaporware
... I was wondering how you use the potentiometer to vary the brightness?
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Brightness on an LED is a function of current, not voltage -- it requires a specified voltage to work at all.
As obelix explained, you just wire up the center post (the wiper) and one of the side posts and the result varies the resistance, which for a constant voltage, varies the current (
Ohm's Law, and all that
).
The only things I'd add are:
You can, if you want to,
also connect the wiper post to the
other side post (in
addition to the center one, wire them together I mean) -- it doesn't really make any difference electrically, but it looks a bit neater to some folks.
I'd suggest you connect your power to the post clockwise from the wiper post, that way as you turn the potentiometer clockwise the resistance will decrease, increasing the current and the LED brightness, and counter-clockwise will turn the LED 'down' -- that's the way most folks expect controls to work (clockwise 'up' and counter-clockwise 'down'), so it's usually more intuitive.
If your potentiometer isn't obvious about which post is which, you can always test it before you soldier the connections.