CN2422788Y - Electronic ballast - Google Patents

Abstract

The utility model belongs to the illuminating electric appliance class. In a general electronic ballast, resonance current flowing through the lamp filaments of a fluorescent lamp increases the energy loss of the electronic ballast and decreases the energy-saving rate of the electronic ballast. The utility model using the closed contact of a relay to bypass the resonance current of the lamp filament of the fluorescent lamp can eliminate generated energy loss. The electronic ballast can save electricity more than 10 percents on the basis of the original electronic ballast, and can simultaneously solve the puzzle of the preheated starting of the electronic ballast.

Description

A kind of electric ballast

The utility model belongs to the electric lighting class.

Series of advantages such as electric ballast has that conversion efficiency height, absence of audio noise, flicker free, startup are fast, line power factor height and system's light efficiency height, with 40 the most frequently used tile type fluorescent lamps is example, after using electric ballast, because of the cancellation inductance type ballast can economize on electricity 8 watts; If the output operating frequency of electric ballast is 25 KHz, then its luminous efficiency can improve at least 12%; If itself consumes energy by 1.5 watts, then its fractional energy savings can reach 30.2%.But the product fractional energy savings that actual production is come out only can reach about 20%, where is remaining electric energy that saves? as can be seen from Figure 1, the illuminator that generally comprises electric ballast is made up of conventional electrical ballast and fluorescent lamp tube, conventional electric ballast comprises rectifier power source, switching circuit, current-limiting inductance L and resonance capacitor C x etc., the high-frequency current that generates after the alternating current process rectification circuit of input and the switching circuit conversion is by current-limiting inductance L current limliting and be divided into two-way, wherein one the tunnel is the lamp current Id that flows through fluorescent tube, and another road is the resonance current Ic of Filament of fluorescent lamp and resonance capacitor C x of flowing through.And when using common inductance type ballast, be not have above-mentioned resonance current, this resonance current makes electric ballast increase extra energy loss just.When operate as normal, the Id of 40 watts of fluorescent tubes is about 0.43 ampere; Ic then with resonant tank in the relating to parameters of element, for 40 watts electric ballast, when Cx was 153, Ic was about 0.4 ampere; When Cx was 103, Ic was about 0.28 ampere.Because this electric current flows through filament, and filament to belong to be resistance element, so the heat release loss must take place.According to reality test, when Cx was 153, the effective value of the voltage drop of single-ended filament can reach more than 10 volts, so the total power consumption of two ends filament can reach more than 8 watts, and this has equaled the power consumption of inductance type ballast.If Cx is 103 o'clock, the effective value of the voltage drop of single-ended filament also will be more than 6.5 volts, and this moment, the total power consumption of two ends filament can reach 3.6 watts.If reduce the capacity of Cx again, resonance current Ic can also corresponding reducing, but can make electric ballast job insecurity when voltage fluctuation cause the fluorescent tube flicker.Therefore, take into account the influence of each side, the value of Cx is not less than 103.Nonetheless, the power consumption on the filament still accounts for about 10% of system power dissipation, and this can't but be a very big energy waste.

The purpose of this utility model be exactly to reduce above-mentioned on Filament of fluorescent lamp by power consumption that resonance current produced.

The technical solution of the utility model is by shown in the electrical schematic diagram of the electric ballast of Fig. 2, compared to Figure 1, the small-sized DC relay J that has increased current-limiting resistance R1, a thermistor Rt and an amphinucleus point that is characterised in that of the present utility model, its connected mode in circuit is: the output of receiving rectifier power source in the conventional electrical ballast after the coil series connection of R1, Rt and J again; The a pair of normal opened contact K1 of relay J is in parallel with resonant capacitance Cx; The a pair of normally closed contact K2 of relay J is in parallel with one group of filament of fluorescent lamp, its another to normally closed contact K3 then with fluorescent lamp another the group filament in parallel, when the fluorescent lamp operate as normal, described relay normally open contact K2 and K3 are in closure state.Operation principle of the present utility model is as follows: after electric ballast inserts electrical network, because the resistance of thermistor is less under the cold conditions, therefore through the electric current that current-limiting resistance and thermistor offer relay coil relay is moved by rectifier power source rapidly, its normal opened contact K1 closure makes lamp tube ends be in short-circuit condition, so fluorescent tube can not lighted; And the electric current that normally closed contact K2 and K3 disconnection provide switching circuit can heat to filament.Through after one of short duration period (about about 2 seconds, can reach by adjusting R1), filament is fully heated, increase along with the thermistor resistance, the electric current that flows through relay coil reduces gradually, when keeping electric current less than it, relay resets, the normal opened contact K1 of on turn-offs again, lamp tube ends (being resonant capacitance Cx two ends) is set up voltage immediately and is risen rapidly, when reaching lamp lighting-up voltage, fluorescent tube is lighted,, the sputtering phenomenon of lamp cathode and emission coating thereof just can not take place at once owing in this process, there is not high pressure to produce; Meanwhile, normally closed contact K2 and K3 are also closed again, resonance current are gone over the short circuit of lamp tube ends filament from the filament bypass respectively, have so just eliminated the power consumption of resonance current on filament fully.The pipeline start up by preheating part only consumes very little power during circuit operate as normal shown in Figure 2, promptly approximates the power consumption of thermistor.

The utility model compared with prior art not only can be further energy-conservation, and solved the difficult problem of the pipeline start up by preheating of electric ballast simultaneously.During with 40 watts of fluorescent tube test pipeline start up by preheating states, actual measurement filament pre-heating electric current does not surpass 650 milliamperes of starting current values of correlation standard less than 600 milliamperes.The startup comparative test result of using the fluorescent tube of same brand to carry out shows, do not have the electric ballast of preheating device to start 1000 left and right sides fluorescent tubes and just begins blackout; Adopt the electric ballast of soft starting mode, start 3000 left and right sides fluorescent tubes and just begin blackout; And adopt the relay preheating method, starts 30000 times after, the not change substantially of the color of lamp tube ends, promptly its number of starts exceeds an order of magnitude than the former.Thus comparative test result as can be known the performance of relay preheating method be quite superior.

Description of drawings:

Among Fig. 1: L is a current-limiting inductance; Cx is a resonant capacitance.

Among Fig. 2: R1 is a current-limiting resistance; Rt is a thermistor; J is the amphinucleus point relay; L is a current-limiting inductance; K1 is the normal opened contact of relay J; K2, K3 are the normally closed contact of relay J; Cx is a resonant capacitance.

Scheme shown in Figure 2 is a most preferred embodiment of the present utility model.

Claims (2)

1. general electric ballast comprises rectifier power source, switching circuit, current-limiting inductance L and resonance capacitor C x, the small-sized DC relay J that has increased current-limiting resistance R1, a thermistor Rt and an amphinucleus point that is characterised in that of the present utility model, a pair of normal opened contact K1 of relay J is in parallel with resonant capacitance Cx; The a pair of normally closed contact K2 of relay J is in parallel with one group of filament of fluorescent lamp, its another to normally closed contact K3 then with fluorescent lamp another the group filament in parallel.

2. according to the described electric ballast of claim 1, it is characterized in that described relay J, its connected mode in circuit is: the output of receiving rectifier power source in the conventional electrical ballast after the coil series connection of R1, Rt and J again.