What is the difference between a preheated ballast and a non-preheated ballast?
The filament life of a preheated ballast is much longer, which means that the tube can last longer, and the average preheating time is the most appropriate.
A preheated ballast or cold start is when the bulb lights up and requires the filament to cool down to a certain temperature It is usually a low price for inductance ballast A non-preheated ballast or heat start-up is the ability to turn off the lights at any time without waiting Electronic ballast is usually more expensive
Non-preheated ballast When the switch is closed circuit of 220 v, 50 hz ac power, the electric current flows through the ballast, lamp filament to the starter filament heating (at the beginning of the starter is broken, due to exert a greater than 190 v ac voltage, the starter has jump of gas inside the bubble inside the arc discharge, the bimetallic strip heating deformation, two electrodes together, form a path to the filament heating), when the starter of the two electrodes together, since there is no arc discharge, bimetallic strip cooling, poles apart, due to the inductance ballasts are perceptual, when the circuit is suddenly interrupted, duration on both ends of the lamp will produce about 1 ms pulse voltage 600 v to 600 v, the exact voltage value depends on the kind of light, in the case of discharge, the ends of the lamp voltage drop, immediately the lamp current limiting effect on the ballast on the one hand, on the other hand make the supply voltage and the working current of the lamp produces 55. - 65. The phase difference of the lamp, which keeps the lamp's secondary start voltage, makes the lamp more stable.
Preheated ballast Electronic ballast is a converter that converts the frequency ac power to high frequency ac power supply. The mains power supply is converted into a dc power source by rf interference (RFI) filter, full wave rectifier and passive (or active) power factor corrector (PPFC or APFC). Through the DC/AC converter, the output of 20 k - 100 KHZ high frequency AC power, added to the LC series resonance circuit, which is connected with lamp heating filament, but make tubes "discharge" "conduction" state, then enter a state of luminescence, high frequency inductive limit the increase of current role at this time, guarantee the normal work of the tubes for the lamp voltage and lamp current, in order to improve the reliability, often add various protection circuit, such as abnormal protection and surge voltage and current protection, temperature protection and so on.
