Hi,
I want to control the intensity of a 1000 W halogen light (120 V AC) using the output of an analog output card from my PC (0 - 10 V, 0 - 5 V etc.). I have come across some voltage controlled dimming circuits, but I wanted to see if any one had any suggestions.

Thanks
Don

 

You can buy these ready-made. Expensive, but probably easier than building.
0-10V input available. Phase-angle control.

See:-

http://www.crydom.com/en/Products/Catalog/m_cpc.pdf

 

Hi,
Thank you for this link, it is very interesting. In the data sheet, it says resistive loads only, do you know if halogen lamps will cause any problems? I am operating the halogen off the main line (120 V AC) so I don't think there should be a large amount of inductance.

 

The "halogen cycle" in the lamps depend on having a very hot glass envelope. If you lower the average voltage to the lamp, the glass does not get to the proper temperature. This results in a darkening of the inside of the glass due to the tungsten deposit that should have evaporated and returned to the filament. This will also result in thinning of the filament and a shorter lamp life.

Ken

 

A halogen lamp is a resistive load.