EVLB001 Datasheet, PDF (9/35 Pages) ATMEL Corporation – Automatic microcontroller dimmable ballast

Section 4
Ballast Demonstrator Operation
4.1 General
Requirements
• Constant power as determined by DALI or Switch Control
400 volt DC bus as provided by a power factor correcting boost regulator (PFC)
100% to 2% dimming setting
• One or two lamps, type T8 of 18W
Ballast to compensate automatically
Hardware is capable of up to 40W per lamp
• Line voltage of 90 to 265 VAC, 50 or 60 Hz
• Control method
DALI power control – auto recognition of control means
One touch “Switch” dimming100% ON after ignition then dim to the last or current
programmed value, if any.
4.2
Startup features Software based features that are not fully implemented.
End users are invited to develop features based on the following characteristics.
•Auto re-strike
-Missing lamp detection allows a default power of 100% on the remaining lamp with
no dimming.
-Open filament detection for one or two lamps as determined by combination of
400VDC current plus lamp voltage prior to ignition.
-On board physical jumper to set for one or two lamp normal operation.
•Shorted filament
-Detection by voltage sense across lamp during preheat. 400VDC current monitor
detects over current limit upon startup. The microcontroller will sense the expected
DC current to the half bridge and resonant circuit relative to the drive frequency.
ATAVRFBKIT / EVLB001 User Guide
4-7
7597B–AVR–10/07