CN201533441U - Series output double-lamp electronic ballast circuit - Google Patents

Abstract

The utility model discloses a two lamp electronic ballast circuits of series connection output, including EMC filter circuit, bridge rectifier filter circuit, the high frequency oscillation circuit who connects in order, the high frequency oscillation circuit is including the first drive tube, the second switch tube of being connected with bridge rectifier filter circuit, and first switch tube links to each other and forms high frequency oscillation circuit's central point with the second switch tube, is connected with inductance, transformer in order on this central point, and it has two light sources to establish ties on this transformer. The utility model has the advantages of the circuit working method is stable, the product performance parameter is reliable and stable, longe-lived.

Description

A dual-lamp electronic ballast circuit with serial output

[technical field]

The utility model relates to an electronic ballast, in particular to a double-lamp electronic ballast circuit with serial output.

[Background technique]

The one-to-two electronic ballasts on the existing market basically adopt the parallel connection method in the output mode of the lamp tube, that is, it is divided into two routes from the center point of the high-frequency oscillation circuit, and then connected to the light tube through an inductor and a capacitor. The two light pipes are outside the parallel position. This kind of connection makes the two light pipes have little influence on each other and can work independently. At the same time, the disadvantages are that the current in the high-frequency oscillation circuit doubles, the current flowing through the switch tube doubles, and the working current in the line is large. Therefore, the temperature of the transistor in the electronic ballast rises, and the ballast as a whole The temperature rises, the product performance parameters are unreliable, the life is short, and the difficulty of electronic ballast design is increased.

[utility model content]

The utility model overcomes the shortcomings of the above-mentioned technologies, and provides a dual-lamp electronic ballast circuit with serial output. The circuit works in a stable manner, which is equivalent to the working characteristics of a single-lamp electronic ballast, and has stable and reliable product performance parameters, Features such as long life.

In order to achieve the above object, the utility model adopts the following technical solutions:

A dual-lamp electronic ballast circuit with serial output, including an EMC filter circuit, a bridge rectification filter circuit, and a high-frequency oscillation circuit connected in sequence, and the high-frequency oscillation circuit includes a first connected to the bridge rectification filter circuit A driving tube Q1, a second switching tube Q2, the first switching tube Q1 and the second switching tube Q2 are connected to form a center point of a high-frequency oscillation circuit, and an inductor L4-1, a transformer T1- 3. The other end of the transformer T1-3 is connected to a pin of the filament at the first end of the second light source LAMP2, and a capacitor C21 is connected between the other pin of the filament at this end and a pin at the end of the filament at the end of the second light source LAMP2. The other pin of the filament at the end of the second light source LAMP2 is connected to one pin of the first filament of the first light source LAMP1, and the other pin of the filament at the first end of the first light source LAMP1 is connected to one pin of the filament at the end of the first light source LAMP1 A capacitor C20 is connected between them. The other pin of the filament at the end of the first light source LAMP1 is connected to capacitors C17 and C18. The other end of capacitor C17 is connected to the negative pole of the bridge rectifier filter circuit. The other end of capacitor C18 is connected to the bridge rectifier filter The positive side of the circuit is connected.

The second light source LAMP2 and the second light source LAMP2 connect the two lamp tubes together through an inductor L4-2 and a capacitor C22, one end of the inductor L4-2 is connected to the inductor L4-1, and the inductor L4-2 At the same time, the other end of the inductor L4-2 is connected to the other pin of the tail filament of the second light source LAMP2, and the other end of the inductor L4-2 is connected to a pin of the first end filament of the first light source LAMP1 through the capacitor C22.

The high-frequency oscillating circuit also includes a shunt resonant capacitor C9, one end of the shunt resonant capacitor C9 is connected to the common end between the inductor L4-1 and the transformer T1-3, and the other end of the capacitor C9 is connected to the positive pole of the bridge rectifier filter circuit .

The capacity of the capacitor C22 is 0.1uF-10uF, and the withstand voltage of the capacitor C22 is greater than 50V; the capacities of the capacitors C20 and C21 are both 1nF-100nF, and the withstand voltage of the capacitors C20 and C21 is greater than 250V; the inductor L4- 1. The sum of the inductances of the inductor L4-2 is 0.5mH-10mH, the capacity of the capacitor C9 is 1nF-100nF, and the withstand voltage of the capacitor C9 is greater than 250V.

An abnormality protection circuit is also connected between the second switching tube Q2 of the high frequency oscillation circuit and the filament of the second light source LAMP2.

Compared with the prior art, the beneficial effects of the utility model are: 1. In the utility model, the two light sources are connected in series to the high-frequency oscillation circuit, the working current in the circuit is small, and the transistor in the electronic ballast The temperature is not high, it has the advantages of stable and reliable product performance parameters, long life, saving raw material costs, and high cost performance;

2. If one light source or two light sources are not connected in the utility model, the high-frequency oscillation circuit will be disconnected, no resonance will be generated, no work will be performed, and the one-to-two electronic ballast will not be damaged;

3. There are inductance and capacitance connected in series between the filaments of the two light sources. When starting high-frequency oscillation, the filament is heated to maintain the thermal electron emission capability of the filament and ensure the luminous efficiency and life of the light source. Due to the inductance and capacitance function, making the two act like a light source;

4. The high-frequency oscillation circuit also includes a shunt resonant capacitor, which has a shunt resonance effect, improves the working state of the high-frequency oscillation circuit, and makes the high-frequency oscillation circuit work more reliably and stably;

5. An abnormality protection circuit is also connected between the second switching tube of the high-frequency oscillation circuit and the filament of the second light source. This abnormality protection circuit can make the entire high-frequency oscillation circuit in a state of The vibration stop state reaches the protection function.

[Description of drawings]

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

Fig. 2 is the schematic circuit diagram of the utility model.

[Detailed ways]

Below in conjunction with accompanying drawing and embodiment of the present utility model, further describe in detail:

As shown in Figure 1, the utility model is a dual-lamp electronic ballast circuit with serial output, including an EMC filter circuit 1, a bridge rectifier filter circuit 2, and a high-frequency oscillation circuit 3 connected in sequence.

As shown in FIG. 2, the high-frequency oscillation circuit 3 includes a first switch tube Q1 and a second switch tube Q2 connected to the bridge rectifier filter circuit 2, and the first switch tube Q1 is connected to the second switch tube Q2 to form a The central point of the high-frequency oscillation circuit 3 is connected with an inductance L4-1 and a transformer T1-3 in sequence, and the other end of the transformer T1-3 is connected with a pin of the filament at the head end of the second light source LAMP2. A capacitor C21 is connected between the other pin of the end filament and one pin of the tail filament of the second light source LAMP2, and the other pin of the tail filament of the second light source LAMP2 is connected to one pin of the head filament of the first light source LAMP1 A capacitor C20 is connected between the other pin of the first end filament of the first light source LAMP1 and one pin of the end filament of the first light source LAMP1, and the other pin of the end filament of the first light source LAMP1 is connected to capacitors C17, C18 The other end of the capacitor C17 is connected to the negative pole of the bridge rectifier filter circuit 2, and the other end of the capacitor C18 is connected to the positive pole of the bridge rectifier filter circuit 2. In the utility model, the two light sources LAMP2 and LAMP1 are connected in series in the high-frequency oscillation circuit 3. If one light source or two light sources are not connected, the high-frequency oscillation circuit 3 is disconnected, no resonance is generated, no work is performed, and no one is caused. The electronic ballast of dragging two is damaged, which is different from the parallel output of one dragging two electronic ballasts commonly used in the market.

The second light source LAMP2 and the second light source LAMP2 connect the two lamp tubes together through an inductor L4-2 and a capacitor C22, one end of the inductor L4-2 is connected to the inductor L4-1, and the inductor L4-2 At the same time, the other end of the inductor L4-2 is connected to the other pin of the tail filament of the second light source LAMP2, and the other end of the inductor L4-2 is connected to a pin of the first end filament of the first light source LAMP1 through the capacitor C22.

The high-frequency oscillation circuit 3 also includes a shunt resonant capacitor C9, one end of the shunt resonant capacitor C9 is connected to the common end between the inductor L4-1 and the transformer T1-3, and the other end of the capacitor C9 is connected to the positive pole of the bridge rectifier filter circuit connect. Due to the shunt resonance effect of the shunt resonant capacitor C9, the working state of the high frequency oscillation circuit 3 is improved, making the high frequency oscillation circuit 3 work more reliably and stably.

The capacity of the capacitor C22 is 0.1uF-10uF, and the withstand voltage of the capacitor C22 is greater than 50V; the capacities of the capacitors C20 and C21 are both 1nF-100nF, and the withstand voltage of the capacitors C20 and C21 is greater than 250V; the inductor L4- 1. The sum of the inductances of the inductor L4-2 is 0.5mH-10mH, the capacity of the capacitor C9 is 1nF-100nF, and the withstand voltage of the capacitor C9 is greater than 250V.

According to different light sources, the power, tube voltage and current of the light source have an impact on the performance parameters of the electronic ballast, and only need to adjust this component to meet the requirements, so that the electronic ballast works stably and reliably.

As shown in Figure 2, after the mains electricity passes through the EMC filter circuit 1 and the bridge rectifier filter circuit 2, it is directly sent to the first switching tube Q1, the second switching tube Q2, the transformer T1, the inductor L4, and the resistors R7, R8, and R5. , R6, capacitor C9 and other components of the high-frequency oscillation circuit 3, so that the electronic ballast to start working. Among them, inductor L4-1, capacitor C9, transformer T1-3, second light source LAMP2, capacitor C21, inductor L4-2, capacitor C22, first light source LAMP1, capacitor C20, capacitor C17, and capacitor C18 form a double-lamp series oscillation circuit . Since the inductance L4-2 and the capacitor C22 are connected in series between the filaments of the second light source LAMP2 and the first light source LAMP1, when the high-frequency oscillation is started, the filament is heated to maintain the thermal electron emission capability of the filament and ensure the light source The luminous efficiency and lifespan are due to the effect of inductor L4-2 and capacitor C22, making the second light source LAMP2 and the first light source LAMP1 like a light source, with stable and reliable product performance parameters, long life, saving raw material costs, and high cost performance. advantage.

In the utility model, an abnormality protection circuit 4 is also connected between the second switch tube Q2 of the high-frequency oscillation circuit 3 and the filament of the second light source LAMP2. The abnormality protection circuit 4 includes an electrolytic capacitor C10, a voltage stabilizing diode DZ1, a switch tube Q3 and Q4, when the two light sources are abnormal or have a rectification effect, when the voltage sampled by the electrolytic capacitor C10 is higher than the turn-on voltage of the Zener diode DZ1, the Zener diode DZ1 is turned on, and the switch tubes Q3 and Q4 are turned on, thus turning on The base potential of the second switching tube Q2 is pulled down, and the entire high-frequency oscillation circuit 3 is in a vibration-stop state, achieving a protection function.

Claims (5)

1. a double-lamp electronic ballast circuit of series output, comprising an EMC filter circuit (1), a bridge rectifier filter circuit (2), and a high-frequency oscillation circuit (3) connected in sequence, is characterized in that: the The high-frequency oscillating circuit (3) includes a first drive tube (Q1) and a second switch tube (Q2) connected to the bridge rectifier filter circuit (2), and the first switch tube (Q1) and the second switch tube (Q2) ) and form the central point of the high-frequency oscillation circuit (3), on which the inductor (L4-1) and the transformer (T1-3) are connected in sequence, and the other end of the transformer (T1-3) is connected to the second One pin of the filament at the first end of the light source (LAMP2) is connected, and a capacitor (C21) is connected between the other pin of the filament at this end and a pin at the end of the filament at the second light source (LAMP2). The second light source (LAMP2) The other pin of the tail filament is connected to one pin of the first light source (LAMP1) head filament, and the other pin of the first light source (LAMP1) head filament is connected to one of the first light source (LAMP1) tail filament A capacitor (C20) is connected between the pins, the other pin of the filament at the end of the first light source (LAMP1) is connected to the capacitors (C17, C18), and the other end of the capacitor (C17) is connected to the bridge rectifier filter circuit (2) The negative poles are connected, and the other end of the capacitor (C18) is connected with the positive pole of the bridge rectifier filter circuit (2). 2. A dual-lamp electronic ballast circuit with serial output according to claim 1, characterized in that the second light source (LAMP2) is connected to the second light source (LAMP2) through an inductor (L4-2) and The capacitor (C22) connects the two light tubes together, one end of the inductor (L4-2) is connected to the inductor (L4-1), and this end of the inductor (L4-2) is simultaneously connected to the tail end of the second light source (LAMP2) The other pin of the filament is connected, and the other end of the inductor (L4-2) is connected to one pin of the first end filament of the first light source (LAMP1) through a capacitor (C22). 3. A dual-lamp electronic ballast circuit with serial output according to claim 2, characterized in that said high-frequency oscillation circuit (3) also includes a shunt resonant capacitor (C9), and the shunt resonant capacitor (C9 ) is connected to the common terminal between the inductor (L4-1) and the transformer (T1-3), and the other end of the capacitor (C9) is connected to the positive pole of the bridge rectifier filter circuit. 4. A dual-lamp electronic ballast circuit with serial output according to claim 3, characterized in that: the capacity of the capacitor (C22) is 0.1uF-10uF, and the withstand voltage of the capacitor (C22) is greater than 50V; The capacities of the capacitors (C20, C21) are all 1nF-100nF, and the withstand voltage of the capacitors (C20, C21) is greater than 250V; the sum of the inductances of the inductors (L4-1) and the inductors (L4-2) is 0.5mH-10mH, the capacity of the capacitor (C9) is 1nF-100nF, and the withstand voltage of the capacitor (C9) is greater than 250V. 5. A dual-lamp electronic ballast circuit with serial output according to claim 1, characterized in that: between the second switching tube (Q2) of the high-frequency oscillation circuit (3) and the second light source (LAMP2) An abnormality protection circuit (4) is also connected between the filaments.

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