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Section 1
Introduction
Efficient fluorescent lamps and magnetic ballasts have been the standard lighting fixture
in commercial and industrial lighting for many years. Several lamp types, rapid start,
high output, and others are available for cost effective and special applications. This
user guide covers operation and development details of the non-dimmable version of
our fluorescent ballast for operating a variety of lamps that are available today. This
guide also covers power electronic circuits that find wide utilization in other applications
beyond lighting alone, which include Power Factor Correction, Half-Bridge Inverter
Drives, and Charge Pump Regulators all employing a variety of IXYS / Atmel parts.
Typical rapid start fluorescent lamps have two pins at each end with a filament across
the pins. The lamp has argon gas under low pressure and a small amount of mercury in
the phosphor coated glass tube. As an AC voltage is applied at each end and the fila-
ments are heated, electrons are driven off the filaments that collide with mercury atoms
in the gas mixture. A mercury electron reaches a higher energy level then falls back to a
normal state releasing a photon of ultraviolet (UV) wavelength. This photon collides with
both argon assisting ionization and the phosphor coated glass tube. High voltage and
UV photons ionize the argon, increasing gas conduction and releasing more UV pho-
tons. UV photons collide with the phosphor atoms increasing their electron energy state
and releasing heat. Phosphor electron state decreases and releases a visible light pho-
ton. Different phosphor and gas materials can modify some of the lamp characteristics.
Figure 1-1. Fluorescent Tube Composition
Ballast Demonstrator User Guide
-1
7629A–AVR–04/06
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