CN2243161Y - Electronic ballast for fluorescent lamp - Google Patents

Abstract

The utility model relates to an electronic ballast which is formed by the connection of a rectification filtering circuit, a sampling arithmetic circuit, a conversion circuit, an abnormal control circuit and a fluorescent lamp, wherein the cathode of the rectification filter circuit, a sampling resistor R and the abnormal protection control circuit are connected through a point E and a point F, and the abnormal protection control circuit is connected with the conversion circuit through a point A. A pulse transformer B, secondary windings B1, B2, switch tubes K1, K2 and an inductor L are connected with the fluorescent lamp. The utility model with abnormal protection control function is used for starting of fluorescent lamps and has the advantages of simple structure, low cost, small volume, electricity saving, good starting effect and long service life of lamp tubes.

Description

The electronic ballast for fluorescent lamps

The utility model relates to a kind of fluorescent lamp ballast.

Existing fluorescent lamp ballast mainly is an Inductive ballast, the necessary supporting starter of the fluorescent lighting fixture that Inductive ballast is formed, in order to improve the also electric allocating power factor of power factor building-out capacitor, its structure is comparatively complicated, weight is heavier, power consumption is corresponding also bigger, and starter is comparatively difficult when low temperature or low pressure.

The purpose of this utility model be to provide a kind of simple in structure, weight is lighter, can under abnormality, protect and the starter fluorescent lamp without starter and power factor compensation capacitance.

In order to achieve the above object, the utility model has adopted a kind of electronic ballast for fluorescent lamps, it is by rectifying and wave-filtering, sampling computing, conversion, control and fluorescent lamp link to each other unusually, its current rectifying and wave filtering circuit negative pole joins by the circuits for triggering of the controllable silicon D in sample resistance R and the control circuit, the anode of controllable silicon D and the point of the A in the sample circuit join, the negative electrode of controllable silicon D links to each other with the negative pole of rectification circuit, diode D ₁, D ₂, capacitor C ₂And the secondary winding B of pulse transformer B ₃By the secondary ac short circuit loop of controllable silicon D formation pulse transformer B, by controllable silicon D, resistance R ₂, R ₃, capacitor C ₁, C ₂, diode D ₁, D ₂And the secondary winding B of pulse transformer B ₃Form the abnormal protection control circuit, and link to each other by 2 two ends with electric ballast negative pole sample resistance R of E, F, two ends E, the F point of sample resistance R and triggering loop A point link to each other pulse transformer B and secondary winding B with the abnormal protection control circuit ₁, B ₂, switching tube K ₁, K ₂Reaching inductance L and fluorescent lamp joins.

The advantage of the utility model electronic ballast for fluorescent lamps is: (1) is simple in structure, installs and changes conveniently, and integrated cost is lower; (2) save electric energy, the starter effect is better; (3) under abnormality, can protect and starter ballast device operate as normal, prolong the useful life of fluorescent tube.

Description of drawings:

Fig. 1 is the block diagram of the utility model electronic ballast for fluorescent lamps;

Fig. 2 is the utility model circuit theory diagrams.

Embodiment to the utility model electronic ballast for fluorescent lamps describes in further detail below in conjunction with accompanying drawing.

By Fig. 1～Fig. 2 as can be known, the utility model electronic ballast for fluorescent lamps, it is by rectifying and wave-filtering, sampling computing, conversion, control and fluorescent lamp link to each other unusually, its current rectifying and wave filtering circuit negative pole joins by the circuits for triggering of the controllable silicon D in sample resistance R and the control circuit, the anode of controllable silicon D and the point of the A in the sample circuit join, the negative electrode of controllable silicon D links to each other with the negative pole of rectification circuit, diode D ₁, D ₂, capacitor C ₂And the secondary winding B of pulse transformer B ₃By the secondary ac short circuit loop of controllable silicon D formation pulse transformer B, by controllable silicon D, resistance R ₂, R ₃, capacitor C ₁, C ₂, diode D ₁, D ₂And the secondary winding B of pulse transformer B ₃Form the abnormal protection control circuit, and link to each other by 2 two ends with electric ballast negative pole sample resistance R of E, F, two ends E, the F point of sample resistance R and triggering loop A point link to each other pulse transformer B and secondary winding B with the abnormal protection control circuit ₁, B ₂, switching tube K ₁, K ₂Reaching inductance L and fluorescent lamp joins.

Operation principle:

A, as shown in Figure 2, sample resistance R and divider resistance R ₂, R ₃Constitute the circuits for triggering of controllable silicon D;

B, when the ballast operate as normal, according to the rated operational current of ballast, select divider resistance R ₂, R ₃Resistance, constitute certain voltage ratio, make controllable silicon be in closed condition, and leave certain triggering surplus.This will decide according to the rated power of ballast.At this moment the abnormal protection circuit to the operate as normal of ballast without any influence.

C, when ballast occurs when unusual, the electric current that flows through sample resistance R will rise, the pressure drop at R two ends is also risen thereupon, when rising to the value that we need control, through R ₂, R ₃The triggering loop of the controllable silicon D that forms makes controllable silicon D conducting.At this moment by D, D ₁, D ₂, C ₂The circuit of forming makes the secondary winding B of pulse transformer B ₃Ac short circuit, thus make two other secondary B of pulse transformer B ₁, B ₂No longer include pulse output.Switching tube K ₁, K ₂Also just lose base drive signal, thereby closed the main work loop of ballast.Because the conducting of controllable silicon D makes A point current potential approach zero potential, current potential this moment and A point current potential that B is ordered are also more approaching, and trigger tube DB can not be triggered simultaneously.Make ballast be in closed condition very reliably.

Claims (1)

1, a kind of electronic ballast for fluorescent lamps, form by fluorescent lamp, rectification circuit, it is characterized in that: by rectifying and wave-filtering, sampling computing, conversion, control and fluorescent lamp link to each other unusually, its current rectifying and wave filtering circuit negative pole joins by the circuits for triggering of the controllable silicon D in sample resistance R and the control circuit, the anode of controllable silicon D and the point of the A in the sample circuit join, the negative electrode of controllable silicon D links to each other with the negative pole of rectification circuit, diode D ₁, D ₂, capacitor C ₂And the secondary winding B of pulse transformer B ₃By the secondary ac short circuit loop of controllable silicon D formation pulse transformer B, by controllable silicon D, resistance R ₂, R ₃, capacitor C ₁, C ₂, diode D ₁, D ₂And the secondary winding B of pulse transformer B ₃Form the abnormal protection control circuit, and link to each other by 2 two ends with electric ballast negative pole sample resistance R of E, F, two ends E, the F point of sample resistance R and triggering loop A point link to each other pulse transformer B and secondary winding B with the abnormal protection control circuit ₁, B ₂, switching tube K ₁, K ₂Reaching inductance L and fluorescent lamp joins.

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