CN201349352Y - Electronic ballast - Google Patents

Abstract

The utility model relates to the technical field of ballasts, and in particular to an electronic ballast, which includes a rectifier and filter circuit, a DC/AC circuit, a power factor correction circuit, a DC/DC step-down circuit, and an integrated control circuit. Due to the addition of the power factor correction circuit, the utility model can improve the power factor compared with the existing electronic ballast; moreover, the utility model is also provided with an integrated control circuit, which controls the DC/AC circuit to output a working voltage and current suitable for a lamp tube by detecting feedback information of the output voltage and output current of the DC/DC step-down circuit, thereby preventing overvoltage, overcurrent, etc. from occurring, thereby improving the power saving effect.

Description

an electronic ballast

Technical field:

The utility model relates to the technical field of ballasts, in particular to an electronic ballast.

Background technique:

High-pressure sodium lamps, metal halide lamps and other lamps have the characteristics of high brightness, and are especially suitable for use as street lamps or spotlights. However, when high-pressure sodium lamps, metal halide lamps and other lamps are lit, it is necessary to instantly increase the low-voltage alternating current to high-voltage Therefore, high-pressure sodium lamps, metal halide lamps and other lamps cannot be used alone, and must pass through a ballast to start and maintain the stability and continuity of light. There are usually two types of ballasts: electronic ballasts and magnetic ballasts. Electronic ballasts are more superior in terms of energy saving and consumption reduction, and will certainly replace magnetic ballasts.

At present, electronic ballasts usually include a rectification filter circuit and a DC/AC (direct current to alternating current) circuit. The output terminal of the rectification filter circuit is connected to the input terminal of the DC/AC circuit. Finally, the DC/AC circuit converts the direct current into high-voltage alternating current, so that the output alternating current starts the high-pressure sodium lamp, metal halide lamp and other lamps and maintains the state of lighting after lighting. However, this electronic ballast is mainly composed of discrete components Composition, no power factor correction function, high interference harmonic content, low power factor, high power consumption, poor power saving effect, and easy to cause interference or pollution to the power grid.

Utility model content:

The purpose of the utility model is to provide an electronic ballast with high power factor and good power saving effect aiming at the deficiencies in the prior art.

In order to achieve the above object, the technical solution adopted by the utility model is:

It includes rectification and filtering circuit, DC/AC circuit, power factor correction circuit (also known as PFC circuit), DC/DC step-down circuit (also known as BUCK circuit), integrated control circuit, the output terminal of the rectification and filtering circuit and the power factor The input terminal of the correction circuit is connected, the output terminal of the power factor correction circuit is connected with the input terminal of the DC/DC step-down circuit, the output terminal of the DC/DC step-down circuit is connected with the input terminal of the DC/AC circuit, and the DC/AC circuit The output end is connected to the lamp tube; the output end of the DC/DC step-down circuit is connected to the input end of the integrated control circuit for feeding back the output voltage and output current information of the DC/DC step-down circuit; the integrated control circuit The output ends are respectively connected to the input ends of the DC/DC step-down circuit and the input ends of the DC/AC circuit for controlling the DC/DC step-down circuit and the DC/AC circuit; the input ends of the integrated control circuit are connected to the lamp tube , used to monitor the working status of the lamp tube.

The electronic ballast further includes an EMI (electromagnetic interference, electromagnetic interference) filter circuit, the input end of the EMI filter circuit is connected to an external input AC, and the output end of the EMI filter circuit is connected to the input end of the rectification filter circuit.

The input alternating current connected to the input end of the EMI filter circuit is 100V-270V.

The output end of the power factor correction circuit is connected with a low-voltage stabilizing circuit, which is used to provide working power for each circuit.

An ignition output circuit is provided between the integrated control circuit and the DC/AC circuit, and the input ends of the ignition output circuit are respectively connected to the output ends of the integrated control circuit and the output ends of the DC/AC circuit.

The beneficial effects of the utility model are:

An electronic ballast provided by the utility model includes a rectification filter circuit, a DC/AC circuit, a power factor correction circuit, a DC/DC step-down circuit, and an integrated control circuit. The output end of the rectification filter circuit and the power factor correction circuit The input end of the power factor correction circuit is connected to the input end of the DC/DC step-down circuit, the output end of the DC/DC step-down circuit is connected to the input end of the DC/AC circuit, and the output end of the DC/AC circuit connected to the lamp tube; the output end of the DC/DC step-down circuit is connected to the input end of the integrated control circuit for feeding back the output voltage and output current information of the DC/DC step-down circuit; the output end of the integrated control circuit respectively connected to the input end of the DC/DC step-down circuit and the input end of the DC/AC circuit for controlling the DC/DC step-down circuit and the DC/AC circuit; the input end of the integrated control circuit is connected to the lamp tube for To monitor the working status of the lamp tube. Due to the addition of a power factor correction circuit, compared with the existing electronic ballast, the utility model can improve the power factor; moreover, the utility model is also provided with an integrated control circuit, which detects DC/DC step-down The feedback information of the output voltage and output current of the circuit controls the DC/AC circuit to output the working voltage and current suitable for the lamp to prevent overvoltage, overcurrent and other situations, thereby improving the power saving effect.

Description of drawings:

Fig. 1 is a structural block diagram of the utility model

Detailed ways:

The utility model is further described below in conjunction with the accompanying drawings, please refer to Fig. 1, the utility model includes an EMI filter circuit 1, a rectification filter circuit 2, a DC/AC circuit 5, a power factor correction circuit 3, and a DC/DC step-down circuit 4 , Integrated control circuit 6; the input end of the EMI filter circuit 1 is connected to the external input AC power, more specifically, the input AC power connected to the input end of the EMI filter circuit 1 is 100V-270V, that is, the utility model can It is suitable for commonly used alternating current 110V or 220V, so as to facilitate the use of power grids of different specifications; the output end of the EMI filter circuit 1 is connected to the input end of the rectification filter circuit 2, and the EMI filter circuit 1 can interfere with harmonics such as electromagnetic waves of the input alternating current Signal filtering to avoid interference or pollution to the power grid by electronic ballasts; the output end of the rectification filter circuit 2 is connected to the input end of the power factor correction circuit 3, and the output end of the power factor correction circuit 3 is connected to the DC/DC step-down circuit 4 is connected to the input end, the output end of the DC/DC step-down circuit 4 is connected to the input end of the DC/AC circuit 5, and the output end of the DC/AC circuit 5 is connected to the lamp tube 9. Due to the addition of the power factor correction circuit 3, Compared with the existing electronic ballast, the utility model can improve the power factor and reduce the power consumption, and the power factor of the utility model can reach more than 0.95.

The integrated control circuit 6 of the present embodiment is mainly composed of a single-chip microcomputer and a comparator, and the output end of the DC/DC step-down circuit 4 is connected to the input end of the integrated control circuit 6 for feeding back the output of the DC/DC step-down circuit 4 Voltage and output current information; the output terminal of the integrated control circuit 6 is connected with the input terminal of the DC/DC step-down circuit 4 and the input end of the DC/AC circuit 5 respectively, for controlling the DC/DC step-down circuit 4 and DC /AC circuit 5; the integrated control circuit 6 controls the DC/AC circuit 5 to output the working voltage and current suitable for the lamp tube 9 by detecting the feedback information of the output voltage and the output current of the DC/DC step-down circuit 4, so as to prevent overvoltage and overvoltage flow, etc., thereby improving the power saving effect. The input terminal of the integrated control circuit 6 is connected to the lamp tube 9 for monitoring the working state of the lamp tube 9. When the lamp tube 9 has an open circuit, short circuit, overcurrent, or rectification effect, the integrated control circuit 6 will output a protection signal, Control the DC/DC step-down circuit 4 and the DC/AC circuit 5, so that the DC/AC circuit 5 has no voltage output, thereby protecting the lamp tube 9 and prolonging the service life of the lamp tube 9; when the electronic ballast itself is overheated, the integrated control The circuit 6 will output a control signal to the DC/AC circuit 5 to reduce the output power of the DC/AC circuit 5, which not only ensures that the lamp tube 9 will not go out, but also prevents the electronic ballast from being damaged due to overheating.

In this embodiment, the output end of the power factor correction circuit 3 is connected with a low-voltage stabilizing circuit 7 for providing working power for each circuit. The direct current is converted into a stable direct current of 15V and sent to each circuit to provide stable working power for each circuit.

An ignition output circuit 8 is provided between the integrated control circuit 6 and the DC/AC circuit 5 in this embodiment, and the input terminals of the ignition output circuit 8 are respectively connected with the output terminals of the integrated control circuit 6 and the output terminals of the DC/AC circuit 5, The integrated control circuit 6 will output the ignition signal to the ignition output circuit 8, so that the ignition output circuit 8 generates a pulse voltage of several thousand volts, which is applied to the lamp tube 9, so that the discharge tube of the lamp tube 9 breaks down and the lamp tube 9 is lit. And the DC/AC circuit 5 outputs a suitable alternating current to maintain the brightness of the lamp tube 9 .

The working principle of the utility model is: when the integrated control circuit 6 lights the lamp tube 9 through the ignition output circuit 8, the external input alternating current passes through the EMI filter circuit 1 and then is sent to the rectification filter circuit 2, and the rectification filter circuit 2 will The alternating current is converted into direct current and input into the power factor correction circuit 3 for power factor correction. The power factor correction circuit 3 also boosts the input direct current to 400V, and then sends it to the low-voltage stabilizing circuit 7 and the DC/DC step-down circuit 4, The DC/DC step-down circuit 4 converts the input 400V direct current into a voltage value suitable for the operation of the lamp tube 9, and then sends it to the DC/AC circuit 5, and the DC/AC circuit 5 converts the input direct current into an alternating current, and outputs it to the lamp The tube 9 provides working power for the lamp tube 9 .

Of course, the above-described embodiments are only preferred implementations of the present utility model, and are not used to limit the scope of implementation of the present utility model. The equivalent changes or modifications are all included in the scope of the utility model patent application.

Claims (5)

1. An electronic ballast, which includes a rectification filter circuit and a DC/AC circuit, is characterized in that: it also includes a power factor correction circuit, a DC/DC step-down circuit, and an integrated control circuit, and the output of the rectification filter circuit The terminal is connected to the input terminal of the power factor correction circuit, the output terminal of the power factor correction circuit is connected to the input terminal of the DC/DC step-down circuit, the output terminal of the DC/DC step-down circuit is connected to the input terminal of the DC/AC circuit, and the DC The output end of the /AC circuit is connected to the lamp tube; The output end of the DC/DC step-down circuit is connected to the input end of the integrated control circuit for feeding back the output voltage and output current information of the DC/DC step-down circuit; The output terminal of the integrated control circuit is respectively connected to the input terminal of the DC/DC step-down circuit and the input terminal of the DC/AC circuit for controlling the DC/DC step-down circuit and the DC/AC circuit; The input terminal of the integrated control circuit is connected with the lamp tube for monitoring the working state of the lamp tube. 2. An electronic ballast according to claim 1, characterized in that it further includes an EMI filter circuit, the input end of the EMI filter circuit is connected to the external input AC, the output end of the EMI filter circuit is connected to the rectification filter circuit input connection. 3. An electronic ballast according to claim 2, characterized in that: the input alternating current connected to the input end of the EMI filter circuit is 100V-270V. 4. An electronic ballast according to claim 1, characterized in that: the output end of the power factor correction circuit is connected with a low-voltage stabilizing circuit for providing working power for each circuit. 5. An electronic ballast according to claim 1, characterized in that: an ignition output circuit is provided between the integrated control circuit and the DC/AC circuit, and the input terminals of the ignition output circuit are respectively connected to the integrated control circuit The output end is connected with the output end of the DC/AC circuit.

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