HID halogen headlmp controler
HID lamps are completely different from halogen lights- they use a ballast with a a state machine to control the startup current profile after discharge is achieved. They operate around 100V so your 3-12V makes no sense. Here is what start-up looks like (from this site): 

  



As to halogens- there is no evidence that ramping voltage at start-up will substantially extend the life of halogen bulbs (the fact they tend to fail at startup is not evidence), so I would say the appropriate name for such a controller would be 'scam'.