China manufacturer of magnetic ballasts for metal halide flood lights & hps flood lights

Fluorescent lamp ballasts are manufactured for three primary types of fluorescent lamps: preheat, rapid start, and instant start. 

Preheat Operation Lamp electrodes are heated prior to initiating the discharge. A 'starter switch' closes, permitting a current to flow through each electrode. The starter switch rapidly cools down, opening the switch, and triggering the supply voltage across the arc tube, initiating the discharge. No auxiliary power is applied across the electrodes during operation.

Rapid Start Operation Lamp electrodes are heated prior to and during operation. The ballast transformers has two special secondary windings to provide the proper low voltage to the electrodes.

Instant Start Operation Lamp electrodes are not heated prior to operation. Ballasts for instant start lamps are designed to provide a relatively high starting voltage (with respect to preheat and rapid start lamps) to initiate the discharge across the unheated electrodes.

Rapid start is the most popular mode of operation for 4-foot 40 watt lamps and high output 8-foot lamps. The advantages of rapid start operation include smooth starting, long life, and dimming capabilities. Lamps of less than 30 watts are generally operated in the preheat mode. Lamps operated in this mode are more efficient than the rapid start mode as separate power is not required to continuously heat the electrodes. However, these lamps tend to flicker during starting and have a shorter lamp life. Eight-foot 'slimline' lamps are operated in instant start mode. Instant start operation is more efficient than rapid start, but as in preheat operation, lamp life is shorter. The 4-foot 32 watt F32T8 lamp is a rapid start lamp commonly operated in instant start mode with electronic high-frequency ballasts. In this mode of operation lamp efficacy is improved with some penalty in lamp life.

 

In a gas discharge, such as a fluorescent lamp, current causes resistance to decrease. This is because as more electrons and ions flow through a particular area, they bump into more atoms, which frees up electrons, creating more charged particles. In this way, current will climb on its own in a gas discharge, as long as there is adequate voltage (and household AC current has a lot of voltage). If the current in a fluorescent light isn't controlled, it can blow out the various electrical components.

A fluorescent lamp's ballast works to control this. The simplest sort of ballast, generally referred to as a magnetic ballast, works something like an inductor. A basic inductor consists of a coil of wire in a circuit, which may be wound around a piece of metal. If you've read How Electromagnets Work, you know that when you send electrical current through a wire, it generates a magnetic field. Positioning the wire in concentric loops amplifies this field.

This sort of field affects not only objects around the loop, but also the loop itself. Increasing the current in the loop increases the magnetic field, which applies a voltage opposite the flow of current in the wire. In short, a coiled length of wire in a circuit (an inductor) opposes change in the current flowing through it (see How Inductors Work for details). The transformer elements in a magnetic ballast use this principle to regulate the current in a fluorescent lamp.

A ballast can only slow down changes in current -- it can't stop them. But the alternating current powering a fluorescent light is constantly reversing itself, so the ballast only has to inhibit increasing current in a particular direction for a short amount of time. Check out this site for more information on this process.

Magnetic ballasts modulate electrical current at a relatively low cycle rate, which can cause a noticeable flicker. Magnetic ballasts may also vibrate at a low frequency. This is the source of the audible humming sound people associate with fluorescent lamps.

Fluorescent lamps come in all shapes and sizes, but they all work on the same basic principle: An electric current stimulates mercury atoms, which causes them to release ultraviolet photons. These photons in turn stimulate a phosphor, which emits visible light photons. At the most basic level, that's all there is to it!

 

Nobody appreciates better the value of electricity and maintenance cost savings to a property better than the owner.James works with commercial property owners like you to improve lighting quality and save electricity & maintenance costs by making smart lighting upgrade decisions.Remember, lighting retrofits offer commercial property owners the quickest return on investment in terms of electrical cost savings.