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California
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Hello all,

I need a simple way to dim some 12vdc lights manually. I tried a few AC dimmer switches (the ones that are usually used for house lighting), but I couldn't get any 12vdc to flow through them.

This is probably a really simple/stupid question...but are there special DC dimmer switches?  smiley-red

TIA
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Ft. Worth, Texas
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High-power Potentiometer or Rheostat, that can handle the load (amps)?
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Quote
are there special DC dimmer switches?
Yes they are used for dimming LEDs. You can get DC SSRs and feed them with a PWM signal from the arduino.

The normal mains dimmers will not work on DC as they require the fact that AC goes to zero volts twice a cycle to turn them off. This is because they use a Triac.
http://en.wikipedia.org/wiki/TRIAC
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Topsham, Vermont USA
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hi,

You need power transistors and Arduino PWM to dim 12 volt lights..

Here's an example: http://arduino-info.wikispaces.com/ArduinoPower (near the bottom)

Here's a photo:

There is example arduino dimming code at bottom of that page...
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Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
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Thank you all for your replies, they are much appreciated!

I just need a simple solution this time, so I went with an adjustable 100w power resistor capable of handling the 80 watts of lighting. Rheostats at that power rating are far too expensive for me.

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