gotta love WIKI
Digital HID (DHID) ballasts
A
digital HID (DHID) lamp ballast is an electronic ballast that uses a
microprocessor to control and regulate a High-Intensity Discharge (HID) lamp. The
firmware can provide control algorithms to supply varying lamp currents during start-up and during lamp operation. The
firmware controls the initial voltage strike to the bulb to start it and then controls current in the bulb for the most efficient burning of the lamp.[
citation needed]
The main benfits of the Digital HID ballast are: saving of electrical energy and maintenance costs over magnetic ballast HID lamps; automatic loss-of-lumen compensation as the lamp ages; produces up to 40% more lumens per watt than magnetic ballasts; increased life expectancy of the lamp compared to magnetic ballast; DHID ballast generates less heat, reducing air conditioning energy cost; 50% dimming of incoming power produces additional cost savings, with automatically controlled lamp dimming in unoccupied areas.[
citation needed]
DHID ballasts can be used to upgrade existing lamp installations. In a retrofit, the DHID ballast can replace the existing magnetic ballast. The rest of the fixture is reused, and the magnetic ballast can be recycled
ebay guide
The days of the old humming, magnetic core&coil-type HID Ballasts have come to an end. The Digital (electronic) Ballast is the latest in HID Ballast innovation. The Digital Ballasts are more efficient, quieter, cooler and softer/easier on the HID bulb all the while allowing for a much smaller and neater package.
The Digital Ballasts do not have any of the usual transformers or capacitors; instead these ballasts have electronic circuitry doing the same job, only much more efficiently using significantly less current. The Digital Ballast have the capability of self diagnostic and reset, including specific protection circuits to detect various lamp-and ballast-fault conditions allowing to safely shutdown or reset the ballast. When the ballast fires the HID bulb it sends full power to the cold HID bulb. Over time, this shortens the HID bulb life and reduces the output and life span of the increases the power over the next few seconds until the HID bulb has reached full brightness. This is also known as soft starting, which minimizes the damage to the HID bulb and increases its life. After one year of use the usable light coming from HID bulb being used in the coil type ballast would have lost over 10% more usable light over the same period of time.
Anyone try V-HIDs?
Linear Mode
