Advantages of electronic ballast
A. Electronic ballast is adopted, the power factor of the line is above 0.99, the nominal current of the line is small, and the active power loss of the line and distribution transformer is reduced.So as to achieve the purpose of energy saving.
B. The power loss of the electronic ballast is far less than that of the inductive ballast.For example, a 250W electronic ballast has a loss of 6 ~ 11W, while an inductive ballast has a loss of 38W.
C. When the high-intensity discharge lamp is matched with the electronic ballast, its light-efficiency ratio is 1.10, while when it is matched with the inductive ballast, its light-efficiency ratio is between 0.95 and 0.98. Therefore, the luminous efficiency of the high-intensity discharge lamp can be increased by more than 10% after the electronic ballast is adopted.
Constant power output greatly improves the performance of the lamp
A. Keep the color properties of the lamp, such as color temperature and color rendering, consistent throughout the life of the lamp by keeping the tube temperature constant.
B. Greatly extend the service life of the lamp.With the electronic ballast, the high-intensity discharge lamp operates in constant power mode, making its actual service life more than 1.5 times of its nominal life.
C. The high operating frequency of the circuit eliminates the strobe phenomenon inherent in the use of high intensity discharge lamps in conjunction with inductive ballasts.
Disadvantages of electronic ballast:
The job is not stable, easy to go wrong, the overall life is short
In the first half of 2003, the company tested the electronic ballasts of different powers from several manufacturers in China, including platon, jilida, baode and other manufacturers.Laboratory test results show that the electronic ballast is unstable and prone to failure.The maximum life promised by the manufacturer is only three years.
Although electronic ballast has great disadvantages at the present stage, from the perspective of comprehensive cost, the use of electronic ballast has a very obvious advantage, it represents the future development direction of ballast, will have a far-reaching impact on the future development of electric light source industry.
Electronic triggers and capacitors
Most high intensity discharge lamps, such as high pressure sodium lamps, metal halide lamps, etc., require a higher voltage than the power supply voltage to start.Generally different types of HID lamps are required to add 0.6 ~ 5.0kV pulse high voltage.An electronic trigger is a device that produces a pulse of high pressure to start a light bulb.When the bulb ignites, the pulse voltage disappears and the electronic trigger stops working.
The pulse generated by the trigger is a high-frequency pulse, and the distributed capacitance of the circuit has a great influence on it. A large distributed capacitance will cause the pulse amplitude attenuation and the bulb cannot be started.Generally, the distributed capacitance per meter of the circuit is up to 70 ~ 100PF. The user should determine the length of the circuit according to the nominal allowable load capacitance value of the trigger.If the nominal value is 20 ~ 1000PF, the line length must be controlled within 10 meters (the distance from the trigger to the bulb).
The main function of capacitance in the schematic diagram of European standard inductance ballast is power compensation to improve the input power factor of the circuit.Inductive ballast is the inductive load, the power factor is very low, only 0.4-0.5, in parallel capacitor, the power factor can reach about 0.9.
The capacitor in the schematic diagram of American standard inductance ballast is the working capacitor, which together with the inductance in the ballast constitutes the LC leading peak ballast.
Power factor refers to the ratio of active power to apparent power. Input power factor is an important index. Improving this index can not only reduce the line loss, save electric energy, eliminate fire hazard, but also reduce the harmonic pollution to the power supply, improve the power supply quality, and obtain greater economic and social benefits. The optimal input power factor is 1.