Help with 12v halogen lamp control!


Im currently working on an installation that requires a 12v halogen lamp to be controlled by a potentiometer, as a dimming switch type device.

The basic idea is that the lamp will be installed in an 8mm film projector allowing the intensity of the lamp to be controlled by an external potentiometer.

Any help would be greatly appreciated as I am new to arduino and physical computing.



Here is a ciruit:

You can replace IC1 with an Arduino and potentiometer. Get input from potentiometer and output with Arduino PWM set to the right frequency

However, I don't even think you need to go this far. I think a simple NPN transistor circuit for switching high voltage loads should work. You will need a protection diode however.

Infact, you migth be able to go simpler and eliminate the Arduino altogether and just use a pot as a voltage divider. I'm not sure about this, you'll have to look into it.

Here is an article that talks about dimming halogen lights:

thank you!

hopefully I will have this up and running soon

Beware that halogen bulbs will not work very well if/when dimmed. A halogen bulb must be run at full brightness so that the "Tungsten-Halogen Cycle" works inside the bulb to prevent the filament vaporising. If you dim it, the life of the bulb will be reduced, and you may see the inside of the bulb getting coated with a thin film of Tunsgten.

Of course, this may not matter in your application!

What is the watts rating of the lamp?