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

One day, at home the fluorescent light fixture is bad, my wife urged. I went to the market to buy a daylight lamp, changed,but still not bright, change to the shade under test, found that electronic ballast is broken, the ballast spent two years.

I open the ballast to analyze circuit,and found that I learn electronic knowledge is too low, for electronic ballast circuit this simple but do not quite understand, visible everyone know knowledge is too narrow, really is need never too old to learn, modest, continuous learning can not be left behind in the era of science and technology, so I decided to to study, and write them down and share with everyone.

The common progress of fluorescent starter in the circuit is equivalent to a switch capacitor in order to eliminate the power of the electromagnetic interference and the formation of oscillation circuit, increase startup when the pulse voltage, the day light access circuit, a glow starting device two electrode voltage discharge to generate glow, the bimetallic strip is heated and curved and the static contact, and power source, ballast, lamp filament and glow starting device to form a loop, and the current of the filament glows when conducting 2, 3 seconds, double metal cooling fins and a static contact, disconnected, the circuit current suddenly disappeared.

So the ballast to produce a high voltage pulse, it with the power supply voltage is superimposed, added to the two ends of the lamp tube, the gas in the lamp tube under the action of high temperature and high pressure ionization and conduction, gas conduction, issued ultraviolet irradiation of the fluorescence powder, soft light. magnetic coil ballast current changes and coil in the magnetic flux changes, the induced electromotive force, the direction and the current in the opposite direction, so the principle of inductance ballast and stable working current of electronic ballast is in connection with the circuit moments, on both ends of the lamp tube produces a high voltage pulse, the lamp in the inert gas ionization caused by arc discharge.

1) Electronic ballast in the cost, volume, weight, performance, energy saving is better than the inductive ballast, but life is not as inductive ballast;
2) 40W ballasts can not start 20W fluorescent lamp, and 20W ballast can start 40W fluorescent lamp, but not for a long time to use fluorescent lamp starter mounted inside the small capacitor and jump bulb and a branch.

The capacitor is connected in parallel, and the capacitance is between 0.005 f ~ 0.01 f. One of its function is to eliminate the interference of nearby radio equipment; the second is due to the oscillating circuit formed by the capacitor magnetic ballast and delay the cathode preheating time and pulse potential, have for the lamp to start. There are two electrodes in the bubble, the electrode of a U shaped double metal electrode is movable, and the other electrode is static contact. Using their automatic switching function and the working characteristics of the inductive ballast, the lamp cathode is ignited after the discharge is ignited. Quality requirements, environmental temperature at 20 DEG C of four seconds internal take-off, using life of not less than 5000 electronic ballast without starter, in the energy-saving lamps, the current price than fluorescent ballast cheap note: if the two ends of the filament of the lamp light and fluorescent lamps could not be lit, for inductive ballast fluorescent lamp, main reason is starter is a parallel capacitor short-circuit, can be removed after the try may also double sheet metal ineffective; for electronic ballast of fluorescent lamp. The reason is that series in the filament loop resonant capacitor short circuit. If both ends of the filament is bright and the frequency of the device moves frequently, the lamp can not be ignited, then it may be the lamp aging, you can see the filament is bright red, the tube ends burn to black.