CN202103928U - A HID electronic ballast circuit, electronic ballast and high-pressure gas discharge lamp - Google Patents

Abstract

The utility model is suitable for an electron technical field provides a HID ballast circuit, electronic ballast and high-pressure gas discharge lamp, HID ballast circuit includes trigger circuit, still includes: the power half-bridge self-oscillation circuit is used for realizing self-oscillation by utilizing the energization of the Miller capacitor Cdg of the internal power field effect transistor to the diagonal capacitor Cgs and outputting a self-oscillation signal when the original single pulse output by the trigger circuit is excited; and the filtering loop is used for carrying out impedance matching on the self-excited oscillation signal and realizing the conversion from a low-impedance voltage source to a high-impedance constant current source. The embodiment of the utility model provides an utilize the inside intrinsic phase relation of power field effect transistor, produce oscillating signal through power half-bridge self-excited oscillation circuit, carry out impedance match, trigger the HID lamp to this oscillating signal through filter circuit, avoid the stroboscopic harm that leads to the fact people's eye and can pass through the electromagnetic compatibility test.

Description

A HID electronic ballast circuit, electronic ballast and high-pressure gas discharge lamp

technical field

The utility model belongs to the field of electronic technology, in particular to an HID electronic ballast circuit, an electronic ballast and a high-pressure gas discharge lamp.

Background technique

With the increasing demand for environmentally friendly lighting in society, high-pressure gas discharge (High Intensity Discharge, HID) lamps, as a new generation of high-efficiency light sources widely used in the world, have largely replaced halogen lamps and high-pressure mercury lamps with their advantages of energy saving and high brightness. As the most important part of the HID lamp, the ballast determines the quality of the HID lamp.

HID ballasts are divided into HID electronic ballasts and HID inductive ballasts. Among them, HID electronic ballasts have largely replaced HID inductors due to their advantages of constant power, low grid pollution, high power utilization and high electro-optical conversion efficiency. type ballast.

FIG. 1 shows an example circuit of an existing three-stage conversion HID electronic ballast, which includes a rectification and filtering circuit 11 , a boost circuit 12 , a step-down circuit 13 , and a full-bridge drive circuit 14 .

The input terminal of the rectification filter circuit 11 is connected with the AC power supply voltage, the output terminal of the rectification filter circuit 11 is connected with the input terminal of the boost circuit 12, the control terminal of the boost circuit 12 is connected with the chip 16, and the output terminal of the boost circuit 12 is connected with the chip 16. The input end of step-down circuit 13 is connected, and the control end of step-down circuit 13 is connected with the output control end P1 of single-chip microcomputer and auxiliary circuit 17, and the output end of step-down circuit 13 is connected with the input end of full-bridge drive circuit 14, and full-bridge drive The first control terminal of the circuit 14 is connected with the output control terminal P2 of the single-chip microcomputer and the auxiliary circuit 17, the second control terminal of the full-bridge drive circuit 14 is connected with the output control terminal P3 of the single-chip microcomputer and the auxiliary circuit 17, and the first control terminal of the full-bridge drive circuit 14 The three control terminals are connected with the output control terminal P4 of the single-chip microcomputer and the auxiliary circuit 17, the fourth control terminal of the full-bridge drive circuit 14 is connected with the output control terminal P5 of the single-chip microcomputer and the auxiliary circuit 17, and the output terminal of the full-bridge drive circuit 14 of the control terminal is connected with the output control terminal P5 of the single-chip microcomputer and the auxiliary circuit 17. Load HID light connection.

The rectifying and filtering circuit 11 includes: a rectifying bridge 111 and a capacitor C1, the input of the rectifying bridge 111 is the input of the rectifying and filtering circuit 11, the output of the rectifying bridge 111 is grounded through the capacitor C1, and the output of the rectifying bridge 111 and the capacitor C1 It is the output end of the rectification filter circuit 11.

The boost circuit 12 includes: an inductor L1, a diode D1 and a switch tube Q1. One end of the inductor L1 is the input end of the boost circuit 12, the other end of the inductor L1 is connected to the anode of the diode D1, and the cathode of the diode D2 is the boost circuit 12. The drain of the switching tube Q1 is connected to the anode of the diode, the source of the switching tube Q1 is grounded, and the gate of the switching tube Q1 is the control terminal of the boost circuit 12 .

Step-down circuit 13 includes: capacitor C2, switch tube Q2 and diode D2, the anode of capacitor C2 is the input terminal of step-down circuit 13, the negative pole of capacitor C2 is grounded, the drain of switch tube Q2 is connected to the positive pole of capacitor C2, and the switch tube The source of Q2 is connected to the cathode of diode D2, and the anode of diode D2 is grounded.

The full-bridge drive circuit 14 includes: an inductor L2, an inductor L3, a capacitor C3, a capacitor C4, a switch tube Q3, a switch tube Q4, a switch tube Q5, and a switch tube Q6. One end of the inductor L2 is the input end of the full-bridge drive circuit 14, and the inductor The other end of L2 is grounded through the capacitor C3, the connection end of the inductor L2 and the capacitor C3 is connected to the drain of the switch tube Q3, the gate of the switch tube Q3 is the first control terminal of the full-bridge drive circuit 14, and the source of the switch tube Q3 is connected to the drain of the switch tube Q3. The drain of the switching tube Q4 is connected, the gate of the switching tube Q4 is the second control terminal of the full bridge drive circuit 14, the source of the switching tube Q4 is grounded, the drain of the switching tube Q5 is connected to the drain of the switching tube Q3, and the switching tube The gate of Q5 is the third control terminal of the full-bridge drive circuit 14, the source of the switch tube Q5 is connected to the drain of the switch tube Q6, the grid of the switch tube Q6 is the fourth control terminal of the full-bridge drive circuit 14, and the switch tube Q6 The source of the switch tube Q3 and the switch tube Q4 are connected to one end of the inductor L3, the other end of the inductor L3 is the output end of the full-bridge drive circuit 14, and the connection end of the switch tube Q5 and the switch tube Q6 passes through the capacitor C4 grounded.

The ballast adopts low-frequency pulse excitation method to light the lamp, and the third-order transformation of the ballast circuit includes:

Step-up conversion, after the AC power is rectified by the rectifier bridge 111 and filtered by the capacitor C1, the chip 15 performs APFC power factor compensation on it to reduce reactive power. The rectification and filtering of D1 and capacitor C2 raises the voltage to a stable 400V DC voltage. At this time, the boost circuit 12 completes the boost conversion;

BUCK step-down conversion, the 400V DC voltage is discharged through the capacitor C2, and the voltage is reduced to the full-bridge operating voltage of about 80-120V through the switch tube Q2 controlled by the single-chip microcomputer and the auxiliary circuit 17, so as to realize constant power operation, and the diode D2 is used for clamping , at this moment, the step-down circuit 13 completes the voltage conversion;

DC-AC conversion, under the control of the single-chip microcomputer and the auxiliary circuit 17, a full-bridge drive circuit 14 composed of inductor L2, capacitor C3, switch tube Q3, switch tube Q4, switch tube Q5, switch tube Q6, inductor L3 and capacitor C4 Convert the full-bridge working voltage of about 80-120V DC into a low-frequency square wave pulse below 400Hz, usually the working frequency is between 120-180Hz.

According to the experimental statistics, the probability of "acoustic resonance" between 10KHz and 150KHz is very high, and the probability of "acoustic resonance" will become smaller and smaller when the frequency is higher than 250KHz. The three-stage conversion HID electronic ballast It can effectively solve the problem of acoustic resonance and constant power operation, but because it needs to go through three-order conversion, each conversion will reduce the efficiency once, and its working frequency is the same order of magnitude as the power frequency, and the stroboscopic problem still exists. It will also generate a large number of high-order harmonics, making it difficult to pass the EMC (Electro Magnetic Compatibility, electromagnetic compatibility) test.

Utility model content

The purpose of the utility model is to provide a HID electronic ballast circuit, aiming at improving the light efficiency and solving the problems of stroboscopic and difficult to pass the electromagnetic compatibility test of the existing electronic ballast circuit.

The utility model is achieved in that a HID electronic ballast circuit includes a trigger circuit, and the ballast circuit also includes:

When the original single pulse output by the trigger circuit is excited, the Miller capacitance C _dg diagonal capacitance C _gs of the internal power FET is used to enable self-excited oscillation, and the power half-bridge self-oscillation output self-excited oscillation signal An excitation oscillation circuit, the input end of the power half-bridge self-excitation oscillation circuit is connected to the output end of the trigger circuit;

A filter circuit for performing impedance matching on the self-excited oscillation signal to realize conversion from a low-impedance voltage source to a high-impedance constant current source, the input end of the filter circuit is connected to the output of the power half-bridge self-excited oscillation circuit The output end of the filter circuit is connected to the load HID tube.

Further, the power half-bridge self-excited oscillation circuit includes:

Transformer T1, upper arm MOS tube Q7 and lower arm MOS tube Q8;

The terminal with the same name of the primary winding N1 of the transformer T1 is connected to the trigger circuit with the input terminal of the power half-bridge self-excited oscillation circuit, the terminal with the same name of the primary winding N1 of the transformer T1 is grounded, and the first time of the transformer T1 The end with the same name of the primary winding N2 is connected to the control end of the upper arm MOS transistor Q7, the input end of the upper arm MOS transistor Q7 is connected to the power supply voltage, and the output end of the upper arm MOS transistor Q7 is the power half-bridge self-excited oscillation circuit The output end of the transformer T1 is connected to the opposite end of the first secondary winding N2 of the transformer T1, and the opposite end of the second secondary winding N3 of the transformer T1 is connected to the control end of the lower arm MOS transistor Q8. The input end of the arm MOS transistor Q8 is connected to the output end of the upper arm MOS transistor Q7, and the output end of the lower arm MOS transistor Q8 is grounded simultaneously with the same-named end of the second secondary winding N3 of the transformer T1.

Further, the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8 are N-type MOS transistors.

Further, the power half-bridge self-excited oscillation circuit also includes:

Capacitor C8, capacitor C9, Zener diode Z1, Zener diode Z2, Zener diode Z3 and Zener diode Z4;

The first secondary winding N2 of the transformer T1 is connected in parallel with the capacitor C8, the cathode of the Zener diode Z1 and the Zener diode Z2 are connected in parallel with the capacitor C8, and the anode of the Zener diode Z1 It is connected to the terminal with the same name of the first secondary winding N2 of the transformer T1, and the anode of the Zener diode Z2 is connected to the terminal with the same name of the first secondary winding N2 of the transformer T1;

The second secondary winding N3 of the transformer T1 is connected in parallel with the capacitor C9, the cathode of the Zener diode Z3 and the Zener diode Z4 are connected in parallel with the capacitor C9 after being connected in series, and the anode of the Zener diode Z3 It is connected with the opposite terminal of the second secondary winding N3 of the transformer T1, and the anode of the Zener diode Z4 is grounded.

Further, the filtering loop includes:

Capacitor C5, capacitor C6, inductor L4, inductor L5;

One end of the capacitor C5 is the input end of the filter circuit, the other end of the capacitor C5 is connected to one end of the inductor L4, the other end of the inductor L4 is connected to one end of the capacitor C6, and the capacitor The other end of C6 is grounded, the common end of the inductor L4 and the capacitor C6 is connected to one end of the inductor L5, and the other end of the inductor L5 is the output end of the filter loop.

Further, the filtering loop includes:

Transformer T3, capacitor C10, capacitor C11, capacitor C12, capacitor C13, capacitor C14 and inductor L6;

One end of the capacitor C14 is connected to the input end of the filter circuit and the output end of the power half-bridge self-excited oscillation circuit, and the other end of the capacitor C14 is connected to one end of the primary winding N7 of the transformer T3. The other end of the primary winding N7 of the transformer T3 is connected to one end of the inductance L6 and one end of the capacitor C12 at the same time, the other end of the inductance L6 is the output end of the filter circuit, and the other end of the capacitor C12 passes through the The capacitor C13 is grounded, the connecting end of the capacitor C12 and the capacitor C13 is connected to one end of the capacitor C10, the other end of the capacitor C10 is connected to the output end of the trigger circuit through the capacitor C11, and the transformer T3 One end of the secondary winding N8 is the induction power end of the filter circuit, and the other end of the secondary winding N8 of the transformer T3 is grounded.

Further, the ballast circuit also includes an abnormality protection circuit for forcibly cutting off the work of the power half-bridge self-excited oscillation circuit when an abnormality occurs in the ballast circuit, so that the ballast circuit enters a protection state, so The input terminal of the abnormality protection circuit is connected with the induction power supply terminal of the filter circuit, and the control terminal of the abnormality protection circuit is connected with the abnormality control terminal of the power half-bridge self-excited oscillation circuit.

Further, the abnormal protection circuit includes:

Capacitor C15, capacitor C16, resistor R3, resistor R4, resistor R5, diode D4, diode D5, clamp diode D6, switch tube Q11 and bidirectional trigger diode VD2;

The anode of the diode D4 is the control terminal of the abnormal protection circuit, the cathode of the diode D4 is connected to the input terminal of the switching tube Q11, the output terminal of the switching tube Q11 is grounded, and the control terminal of the switching tube Q11 terminal is grounded through the capacitor C15, the resistor R3 is connected in parallel with the capacitor C15, one end of the bidirectional trigger diode VD2 is connected to the control terminal of the switching tube Q11, and the other end of the bidirectional trigger diode VD2 is connected through the capacitor C16 Grounded, the resistor R4 is connected in parallel with the capacitor C16, the other end of the bidirectional trigger diode VD2 is also connected to one end of the resistor R5, the other end of the resistor R5 is connected to the cathode of the diode D5, the The anode of the diode D5 is the input end of the abnormal protection circuit, the clamping diode D6 is connected in parallel with the resistor R4, and the cathode of the clamping diode D6 is connected to the connection between the bidirectional trigger diode VD2 and the resistor R5 terminal, and the anode of the clamping diode D6 is grounded.

Another object of the present invention is to provide an electronic ballast using the above-mentioned HID electronic ballast circuit.

Another object of the present utility model is to provide a high-pressure gas discharge lamp comprising the above-mentioned HID electronic ballast.

In the embodiment of the utility model, the self-feedback of the inherent phase relationship inside the power field effect tube is used to generate an oscillating signal far away from the "acoustic resonance" frequency range of the HID lamp, which effectively avoids the stroboscopic phenomenon and improves the light efficiency. On the basis of power, the power field effect tube is guaranteed to work at low temperature and stably, and the impedance matching of the oscillating signal is carried out through the filter circuit, which can broaden the frequency band and reduce the Q value while achieving constant power supply, making it easier to pass the EMC test and improving The stability and reliability of the power output circuit are improved, and the filter circuit can also replace the drive circuit to trigger the HID lamp, which simplifies the circuit structure and reduces the production cost.

Description of drawings

Fig. 1 is an example circuit diagram of an existing three-stage conversion HID electronic ballast;

Fig. 2 is the structural diagram of the HID electronic ballast circuit provided by an embodiment of the utility model;

Fig. 3 is an example circuit diagram of the HID electronic ballast circuit provided by an embodiment of the present invention;

Fig. 4 is the power FET and its equivalent circuit diagram provided by an embodiment of the utility model;

Fig. 5 is the topology circuit of the HID electronic ballast circuit provided by an embodiment of the utility model;

FIG. 6 is a schematic diagram of frequency spreading and Q reduction of the HID electronic ballast circuit provided by an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

The embodiment of the utility model utilizes the inherent phase relationship inside the power field effect tube to generate an oscillating signal through the power half-bridge self-excited oscillating circuit, and performs impedance matching on the oscillating signal through the filter circuit to trigger the HID lamp, avoiding stroboscopic damage to the human eye. damage and can pass the electromagnetic compatibility test.

Fig. 2 shows the structure of the HID electronic ballast circuit provided by an embodiment of the present invention. For the convenience of description, only the parts related to the present invention are shown.

The HID electronic ballast circuit can be applied to various HID electronic ballasts and high-pressure gas discharge lamps.

The HID electronic ballast circuit provided as an embodiment of the present invention includes a trigger circuit 21, and the HID electronic ballast circuit also includes:

A power half-bridge self-excited oscillation circuit 22, the input end of the power half-bridge self-excited oscillation circuit 22 is connected to the output end of the trigger circuit 21, and is used to utilize the internal power field effect when the original single pulse output by the trigger circuit 21 is excited. The Miller capacitance C _dg of the tube and the diagonal capacitance C _gs are empowered to realize self-excited oscillation and output self-excited oscillation signal;

A filter circuit 23, the input end of the filter circuit 23 is connected to the output end of the power half-bridge self-excited oscillation circuit 22, the output end of the filter circuit 23 is connected to the load HID tube 24, and is used for impedance of the self-excited oscillation signal Matching to realize the transformation from a low impedance voltage source to a high impedance constant current source.

The realization of the utility model will be described in detail below in conjunction with specific embodiments.

Fig. 3 shows an example circuit of the HID electronic ballast circuit provided by an embodiment of the present invention. For the convenience of description, only the parts related to the present invention are shown.

The HID electronic ballast circuit provided as an embodiment of the utility model includes a trigger circuit 31 , a power half-bridge self-excited oscillation circuit 32 and a filter circuit 33 .

The power half-bridge self-excited oscillation circuit 32 includes:

Transformer T1, upper arm MOS tube Q7 and lower arm MOS tube Q8;

The terminal with the same name of the primary winding N1 of the transformer T1 is connected to the input terminal of the power half-bridge self-excited oscillation circuit 32 and the trigger circuit 31, the terminal with the same name of the primary winding N1 of the transformer T1 is grounded, and the terminal with the same name of the first secondary winding N2 of the transformer T1 is connected to the upper arm The control terminal of the MOS tube Q7 is connected, the input terminal of the upper arm MOS tube Q7 is connected to the power supply voltage, and the output terminal of the upper arm MOS tube Q7 is the output terminal of the power half-bridge self-excited oscillation circuit 32 and the first secondary winding N2 of the transformer T1. terminal connection, the opposite end of the second secondary winding N3 of the transformer T1 is connected to the control terminal of the lower arm MOS transistor Q8, the input end of the lower arm MOS transistor Q8 is connected to the output end of the upper arm MOS transistor Q7, and the lower arm MOS transistor Q8 The output end is grounded simultaneously with the same-named end of the second secondary winding N3 of the transformer T1.

As an embodiment of the present invention, the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8 may be N-type MOS transistors.

Filter loop 33 includes:

Capacitor C5, capacitor C6, inductor L4, inductor L5;

One end of the capacitor C5 is the input end of the filter circuit 33, the other end of the capacitor C5 is connected to one end of the inductor L4, the other end of the inductor L4 is connected to one end of the capacitor C6, the other end of the capacitor C6 is grounded, and the common connection between the inductor L4 and the capacitor C6 terminal is connected to one terminal of the inductor L5, and the other terminal of the inductor L5 is connected to the HID as the output terminal of the filter circuit 33.

In the embodiment of the present invention, when the trigger circuit 31 outputs the original single pulse signal, the transformer T1 is excited, and the primary winding N1 of the transformer T1 discharges quickly, so the first secondary winding N2 and the second secondary winding N2 of the transformer T1 Two sine wave induced voltages with the same amplitude and completely opposite phases are induced on the winding N3 respectively, so that the upper arm MOS transistor Q7 in the same phase as the primary winding N1 is saturated and turned on, and the lower arm MOS transistor Q8 is cut off. Therefore, the upper arm MOS transistor Q7 The voltage increment dv/dt between the drain and the source drops rapidly, while the current increment di/dt increases rapidly, and the rapidly changing current flows through the inductor L4 and the capacitor C6 to the ground, completing a "pull" action.

After half a cycle, the upper arm MOS transistor Q7 enters the cut-off state, the phase is negative, the lower arm MOS transistor Q8 is turned on, and the rapidly changing current flows through the inductor L4 and capacitor C6, and quickly discharges to the ground loop through the turned-on lower arm MOS transistor Q8. Complete a "filling" action.

In the embodiment of the present invention, when the upper arm MOS transistor Q7 is turned on, the lower arm MOS transistor Q8 is turned off; when the lower arm MOS transistor Q8 is turned on, the upper arm MOS transistor Q7 is turned off.

Repeat the above cycle, output a square wave signal from the output end of the power half-bridge self-excited oscillation circuit 32 at the middle point of the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8, the amplitude of which is Vcc-2I*Ron, where Vcc is the power supply voltage, I is the rapidly changing current, and Ron is the on-resistance. After the capacitor C5, the inductor L4 and the capacitor C6 frequency selection circuit filter and Q-fold boost, a high-voltage sine wave signal is formed. C5 is a DC blocking capacitor, inductance L4 and capacitor C6 form a series resonance; later, when the HID tube is ignited, the impedance of the HID is greatly reduced, and the inductance L5 and capacitor C6 form a parallel resonant circuit with load consumption. In terms of power supply, it is equivalent to changing from a low-impedance voltage source to a high-impedance current source, thereby realizing current limiting and constant power supply.

The filter circuit 33 can also be used as a starting unit to quickly start the HID lamp. Since the HID lamp is a capacitive load, the static capacitance between the two electrodes is only about a few picofarads. Therefore, when the lamp tube is not ignited, its impedance is very large. When the strong power signal reaches both ends of the load and the lamp has not started, due to the principle of self-induction, a high self-induction voltage will be generated at both ends of the electrodes of the HID lamp. This high voltage is enough to ignite the lamp, and there is no need to design a special trigger Start the circuit. Once the HID lamp is ignited, the impedance immediately drops to a very low level. After entering the normal working state, the voltage at both ends drops to the working voltage, which is about 90-180V.

FIG. 4 shows a power field effect transistor and its equivalent circuit provided by an embodiment of the present invention. For the convenience of description, only the parts related to the present invention are shown.

In the embodiment of the present invention, the "Miller" capacitor is used as the subsequent energization after the power field effect transistor is triggered to be turned on by the original pulse, so that the oscillation frequency can be formed and maintained.

Among them, Rg is the grid equivalent resistance of the power field effect transistor, and its resistance value can be as high as 10 ¹³ Ω in static state, which can be regarded as infinite. The resistance is reduced to a very small value, Ron is the on-resistance, and Rch is the channel resistance. It can be regarded as zero when it is turned on, and it can be regarded as infinite when it is turned off. It can be regarded as a gate switch. Cgs is the angular capacitance between the field effect transistor gate G and the source S, Cdg is the angular capacitance between the drain D and the gate G (ie "Miller capacitance"), and Cds is the drain D and the source S The angular capacitance between them is called the output capacitance, Cs is the decoupling capacitance at both ends of the power supply, which provides a path for AC, Vd is the body diode of the power FET itself, and the connection relationship of the power FET is no longer a common knowledge here. repeat.

In the embodiment of the present invention, referring to Fig. 3, when the upper arm MOS transistor Q7 or the lower arm MOS transistor Q8 in the power half-bridge self-excited oscillation circuit 32 is turned on by a single pulse original impulse, the drain D The voltage V immediately drops at the speed of dv/dt, and at the same time, the current i increases rapidly at the speed of di/dt. The relationship between the rapidly changing current and the voltage gradient is: i=Cdv/dt. di/dt is the increment of the avalanche current to time between the drain and source of the MOS tube. This incremental current charges the gate corner capacitance Cgs through the "Miller" capacitance Cdg of the power FET itself, which is different from the original single The secondary pulse has a definite same phase, so as to energize the gate-source angular capacitance Cgs, maintain the oscillation of the secondary circuit of the excitation coil and the intrinsic frequency of the gate-source angular capacitance Cgs, and make the drain D of the MOSFET tube and the source S further conduction. Since the phases of the input circuits of the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8 in the power half-bridge self-excited oscillation circuit 32 are completely opposite, in the first half cycle, the phase of the gate G of the lower arm MOS transistor Q8 is negative, and the lower arm MOS transistor Q8 is cut off. state, in the second half cycle, the phase of the gate G of the upper arm MOS transistor Q7 is negative, the upper arm MOS transistor Q7 is cut off, and the phase of the lower arm MOS transistor Q8 changes from negative to positive, so the D pole and S pole of the lower arm MOS transistor Q8 conduct Pass, complete a 'pull', 'fill' process to form a power output, and maintain it over and over again.

In this utility model embodiment, the operating frequency of the HID ballast circuit is mainly determined by the first secondary winding N2 of the transformer T1, the input junction capacitance Ciss of the upper arm MOS transistor Q7, the external compensation capacitor Cs or the second secondary winding of the transformer T1 N3, the input junction capacitance Ciss of the lower arm MOS transistor Q8, and the external compensation capacitor Cs are determined.

Since the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8 are positive triggers of T/2 time, and the distributed capacitance C* is very small, the operating frequency can be approximated as:

Assuming that the secondary winding LN2/LN3 of the transformer T1 is 40μH, and adopts FQPF10N30C tube, find out its input junction capacitance Ciss=2200Pf from the device manual, take the frequency fine-tuning capacitor (that is, the compensation capacitor) Cs=220Pf, and substitute it into the above formula, we can get : f=268KHz, which is very similar to the measured result: f=261KHz.

In addition, the secondary winding LN2/LN3 of the transformer T1 is set to be 12μH, FQPF10N30C tube is still used, Ciss+Cs=2400Pf is substituted into the above formula, and f=469KHz can be obtained, which is very close to the actual measurement result: f=452KHz.

而在本实用新型实施例中，N型MOS管为正触发，在一个周期内上、下臂MOS管各有一次导通，叠加之后即为两次，因此，振荡频率为：即当工作频率相同时，若L不变，电容C的数值要比传统电路小4倍，这就使MOSFET管导通时的交换损耗大大降低。Since the resonant frequency of the series or parallel resonant circuit composed of LC is

However, in the embodiment of the present invention, the N-type MOS tube is a positive trigger, and the upper and lower arm MOS tubes are turned on once in one cycle, which is twice after superimposition. Therefore, the oscillation frequency is: That is to say, when the operating frequency is the same, if L remains unchanged, the value of the capacitor C is 4 times smaller than that of the traditional circuit, which greatly reduces the switching loss when the MOSFET tube is turned on.

且利用普通的功率场效应管，将工作频率提高到650KHz-750KHz之间，该频段处于“声共振”概率窗口之外，使得“声共振”和频闪问题同时解决，其电功率可高至250W以上，管子的结温仍然很低，提高了电路的可靠性。The embodiment of the utility model derives the formula based on the principle of subsequent energization of the "Miller" capacitor to generate the oscillation frequency

And use ordinary power field effect tubes to increase the working frequency to 650KHz-750KHz, this frequency band is outside the probability window of "acoustic resonance", so that "acoustic resonance" and stroboscopic problems can be solved at the same time, and its electric power can be as high as 250W Above, the junction temperature of the tube is still very low, which improves the reliability of the circuit.

Fig. 5 shows the topological circuit of the HID electronic ballast circuit provided by an embodiment of the present invention. For the convenience of description, only the parts related to the present invention are shown.

As an HID electronic ballast circuit provided by an embodiment of the present invention, the trigger circuit 51 includes: a resistor R1, a resistor R2, a capacitor C7, a diode D3 and a bidirectional trigger diode VD1;

One end of the resistor R1 is connected to the power supply voltage Vcc, the other end of the resistor R1 is connected to the anode of the diode D3, the cathode of the diode D3 is connected to the input end of the filter circuit 53, one end of the resistor R2 is connected to the anode of the diode D3, and the other end of the resistor R2 passes through The capacitor C7 is grounded, the connection end of the resistor R2 and the capacitor C7 is connected to one end of the bidirectional trigger diode VD1 , and the other end of the bidirectional trigger diode VD1 is the output end of the trigger circuit 51 .

The power half-bridge self-excited oscillation circuit 52 includes:

Transformer T1, capacitor C8, capacitor C9, Zener diode Z1, Zener diode Z2, Zener diode Z3, Zener diode Z4, upper arm MOS transistor Q7 and lower arm MOS transistor Q8;

The terminal with the same name of the primary winding N1 of the transformer T1 is connected to the input terminal of the power half-bridge self-excited oscillation circuit 52 and the trigger circuit 51, the terminal with the same name of the primary winding N1 of the transformer T1 is grounded, and the first secondary winding N2 of the transformer T1 is connected in parallel with the capacitor C8 , Zener diode Z1 and the cathode of Zener diode Z2 are relatively connected in series and connected in parallel with capacitor C8, and the anode of Zener diode Z1 is connected with the terminal of the same name of the first secondary winding N2 of transformer T1 and the control terminal of upper arm MOS transistor Q7 at the same time. The anode of the voltage diode Z2 is connected to the opposite end of the first secondary winding N2 of the transformer T1 and the output end of the upper arm MOS transistor Q7 at the same time, the input end of the upper arm MOS transistor Q7 is connected to the power supply voltage, and the output end of the upper arm MOS transistor Q7 is the power At the output end of the half-bridge self-excited oscillation circuit 52, the second secondary winding N3 of the transformer T1 is connected in parallel with the capacitor C9, the cathode of the Zener diode Z3 and the Zener diode Z4 are connected in parallel with the capacitor C9 after the cathode of the Zener diode Z3 is connected in parallel, and the anode of the Zener diode Z3 is simultaneously The opposite end of the second secondary winding N3 of the transformer T1 is connected to the control end of the lower arm MOS transistor Q8, and the anode of the Zener diode Z4 is simultaneously connected to the same end of the second secondary winding N3 of the transformer T1 and the lower arm MOS transistor The output end of Q8 is grounded, the input end of the lower arm MOS transistor Q8 is connected to the output end of the upper arm MOS transistor Q7, and the opposite end of the second secondary winding N3 of the transformer T1 is the abnormal control end of the power half-bridge self-excited oscillation circuit 52 .

As an embodiment of the present invention, the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8 can be N-type MOS transistors, and the power supply voltage can be 400V DC voltage.

Filter loop 53 includes:

Transformer T3, capacitor C10, capacitor C11, capacitor C12, capacitor C13, capacitor C14, inductor L6;

One end of the capacitor C14 is connected to the input end of the filter circuit 53 and the output end of the power half-bridge self-excited oscillation circuit 52, the other end of the capacitor C14 is connected to one end of the primary winding N7 of the transformer T3, and the other end of the primary winding N7 of the transformer T3 is simultaneously connected to the One end of the inductor L6 is connected to one end of the capacitor C12, the other end of the inductor L6 is connected to one end of the inductor L7, and the other end of the inductor L7 is the output end of the filter circuit 53, which is connected to the load HID lamp 54, and the other end of the capacitor C12 passes through the capacitor C13 is grounded, the connection end of capacitor C12 and capacitor C13 is connected to one end of capacitor C10, the other end of capacitor C10 is connected to the output end of trigger circuit 51 through capacitor C11, and one end of transformer T3 secondary winding N8 is the induction power supply of filter circuit 53 end, the other end of the transformer T3 secondary winding N8 is grounded.

As an embodiment of the present invention, the HID electronic ballast circuit also includes an abnormality protection circuit 55, the input end of the abnormality protection circuit 55 is connected to the induction power supply end of the filter circuit 53, the control end of the abnormality protection circuit is connected to the power half-bridge automatic The abnormality control terminal of the excitation oscillation circuit 52 is connected, and is used for forcibly cutting off the power half-bridge self-excitation oscillation circuit 52 when an abnormality occurs in the HID ballast circuit, so that the HID ballast circuit enters a protection state.

The abnormal protection circuit 55 includes: a capacitor C15, a capacitor C16, a resistor R3, a resistor R4, a resistor R5, a diode D4, a diode D5, a clamping diode D6, a switch Q11 and a bidirectional trigger diode VD2;

The anode of the diode D4 is the control terminal of the abnormal protection circuit 55, the cathode of the diode D4 is connected to the input terminal of the switch tube Q11, the output terminal of the switch tube Q11 is grounded, the control terminal of the switch tube Q11 is grounded through the capacitor C15, and the resistor R3 and the capacitor C15 In parallel, one end of the bidirectional trigger diode VD2 is connected to the control terminal of the switch tube Q11, the other end of the bidirectional trigger diode VD2 is grounded through the capacitor C16, the resistor R4 is connected in parallel with the capacitor C16, and the other end of the bidirectional trigger diode VD2 is also connected to one end of the resistor R5 , the other end of the resistor R5 is connected to the cathode of the diode D5, the anode of the diode D5 is the input end of the abnormal protection circuit 55, the clamping diode D6 is connected in parallel with the resistor R4, and the cathode of the clamping diode D6 is connected to the bidirectional trigger diode VD2 and the resistor R5 The connection end of the clamping diode D6 is grounded.

In the embodiment of the utility model, the 220V AC power becomes a constant voltage 400V DC power supply voltage after rectification, filtering and active power factor compensation, which supplies power to the main circuit and passes through the first resistor R1 and the second resistor R1 in the trigger circuit 51. The resistor R2 charges the capacitor C7. When the voltage on the capacitor C7 rises to the threshold voltage of the bidirectional trigger diode VD1, the block of the bidirectional trigger diode VD1 avalanches, and the original impulse current passes through the transformer T1 in a pulsed manner. The primary winding of the transformer T1 N1 discharges quickly, so two sine wave induced voltages with the same amplitude and completely opposite phases are induced on the first secondary winding N2 and the second secondary winding N3 of the transformer T1 respectively, so that they are in the same phase as the primary winding N1 of the transformer T1 The upper arm MOS transistor Q7 is saturated and turned on, and the lower arm MOS transistor Q8 is cut off. Therefore, the voltage increment dv/dt between the drain and source of the upper arm MOS transistor Q7 drops rapidly, while the current increment di/dt increases rapidly. , the rapidly changing current flows through the DC blocking capacitor C14, the primary winding N7 of the transformer T3 and the capacitors C12 and C13 connected in series to the ground, completing a "pull" action.

After half a cycle, the upper arm MOS transistor Q7 enters the cut-off state, the phase is negative, the lower arm MOS transistor Q8 is turned on, and the rapidly changing current flows through the DC blocking capacitor C14, the primary winding N7 of the transformer T3, and the capacitors C12 and C13 connected in series The ground loop is quickly discharged through the turned-on lower arm MOS transistor Q8 to complete a "filling" action.

In the embodiment of the present invention, when the upper arm MOS transistor Q7 is turned on, the lower arm MOS transistor Q8 is turned off; when the lower arm MOS transistor Q8 is turned on, the upper arm MOS transistor Q7 is turned off.

In the embodiment of the utility model, when the angular capacitance Cgs of the MONSEFT tube is large, increasing the capacitor C10 and the capacitor C11 can speed up the charging speed of the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8, and the values of the capacitor C10 and the capacitor C11 very small.

In the embodiment of the present invention, when the upper arm MOS transistor Q7 is turned on or the lower arm MOS transistor Q8 is turned on, since the voltage on the capacitor C7 in the trigger circuit 51 is discharged to the ground through the second resistor R2 and the diode D3, the capacitor The voltage at both ends of C7 is maintained at about 200V, which is lower than the trigger voltage of 240V of the bidirectional trigger diode VD1, and will not cause retriggering.

Repeat the above cycle, and output a square wave signal from the midpoint of the upper arm MOS transistor Q7 and the lower arm MOS transistor Q8, the amplitude of which is Vcc-2I*Ron, where Vcc is the power supply voltage, I is the rapidly changing current, and Ron is the on-resistance. After the primary winding N7 of the transformer T3 and the capacitor C12 and capacitor C13 in series with it are filtered and Q-fold boosted, a high-voltage sine wave signal is formed, and the primary winding N7 of the transformer T3 forms a series resonance with the capacitor C12 and capacitor C13; Finally, when the HID tube is ignited, the impedance of the HID is greatly reduced, and the inductance L6 and the capacitors C12 and C13 form a parallel resonant circuit with load consumption. For the HID lamp, it is equivalent to changing from a low-impedance voltage source to A high-impedance current source, which enables current limiting and constant power supply, and improves conversion efficiency.

The filter circuit 53 can also be used as a starting unit to quickly start the HID lamp. Since the HID lamp is a capacitive load, the static capacitance between the two electrodes is only about a few picofarads. Therefore, when the lamp tube is not ignited, its impedance is very large. When the strong power signal reaches both ends of the load and the lamp has not started, due to the principle of self-induction, a high self-induction voltage will be generated at both ends of the electrodes of the HID lamp. This high voltage is enough to ignite the lamp, and there is no need to design a special trigger Start the circuit. Once the HID lamp is ignited, the impedance immediately drops to a very low level. After entering the normal working state, the voltage at both ends drops to the working voltage, which is about 90-180V. The inductor L6 can limit the current. Adding capacitor C10 and capacitor C11 connected in series can add a small voltage positive feedback to the outside under the condition of large current and slow switching speed of ordinary field effect tubes to increase the switching speed, and can make the abnormality protection circuit 55 reach microseconds Level or even nanosecond response speed, so that when the start time of the HID lamp is delayed, the protection circuit can be quickly started to protect the upper arm MOS tube Q7 and the lower arm MOS tube Q8 from being damaged.

其中f为工作频率，L为电感量，r为铜阻，该Q值若太高，对电路的稳定性和可靠性不利，因此将频带展宽，降低了谐振回路的高Q频响，相对地降低了电路潜在的风险，提高了功率输出电路的稳定性和可靠性，半桥功率场效应管的结温也大大降低，并且通过将串联谐振滤波回路的低阻抗电压源，转变成并联谐振滤波回路的高阻抗电流源，达到恒功率供电。As an embodiment of the present invention, referring to Fig. 5 and Fig. 6, the primary winding N7 of the transformer T3, the capacitor C12 and the capacitor C13 can form a series resonance, and its resonance frequency is slightly lower than the eigenfrequency of the HID electronic ballast circuit. When the HID is ignited, its impedance is greatly reduced, and the inductance L6 and the capacitor C12 and capacitor C13 form a parallel resonance with power consumption, and its resonance frequency is slightly higher than the intrinsic frequency of the circuit. Slightly staggering the natural frequencies of the two is to widen the frequency band, make it easier to pass the EMC test, and reduce the Q value at the same time. The Q value of the resonant tank is:

Where f is the operating frequency, L is the inductance, and r is the copper resistance. If the Q value is too high, it will be detrimental to the stability and reliability of the circuit. Therefore, the frequency band will be widened and the high Q frequency response of the resonant circuit will be reduced. The potential risk of the circuit is reduced, the stability and reliability of the power output circuit are improved, the junction temperature of the half-bridge power FET is also greatly reduced, and the low-impedance voltage source of the series resonant filter circuit is transformed into a parallel resonant filter The high-impedance current source of the loop achieves constant power supply.

When the abnormality protection circuit 55 is not started or the start-up is delayed, a very high high-frequency voltage will be induced at the two ends of the secondary winding N8 of the transformer T3, through the rectification of the diode D5 and the filtering of the capacitor C16, the A DC voltage is formed, and the clamping diode D6 is used to clamp the voltage. When the DC voltage is higher than the avalanche threshold of the bidirectional trigger diode VD2, the bidirectional trigger diode VD2 is turned on, the switch tube Q11 is turned on, and the lower arm MOS tube Q8 The control end of the diode D4 and the switch tube Q11 have conduction current to the ground, and the lower arm MOS tube Q8 is forcibly cut off, so that the upper arm MOS tube Q7 and the lower arm MOS tube Q8 are not damaged. The response speed of the abnormality protection circuit 55 is very fast, and when the circuit abnormality is canceled, it can be maintained for an appropriate time, so as to ensure that the circuit resumes working after returning to a normal state.

Using the same HID lamp to test the luminous flux, it is measured that the luminous efficiency of the HID electronic ballast circuit provided by the embodiment of the utility model can reach 99.9lm/w, which is 6.2lm/w higher than that of the traditional HID electronic ballast circuit.

In the embodiment of the utility model, the self-feedback of the inherent phase relationship inside the power field effect tube is used to generate an oscillating signal far away from the "acoustic resonance" frequency range of the HID lamp, which effectively avoids the stroboscopic phenomenon and improves the light efficiency. On the basis of power, the power field effect tube is guaranteed to work at low temperature and stably, and the impedance matching of the oscillating signal is carried out through the filter circuit, which can broaden the frequency band and reduce the Q value while achieving constant power supply, making it easier to pass the EMC test and improving The stability and reliability of the power output circuit are improved, and the filter circuit can also replace the drive circuit to trigger the HID lamp, which simplifies the circuit structure and reduces the production cost.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (10)

1. a HID electronic ballast circuit comprises circuits for triggering, it is characterized in that, said ballasting circuit also comprises:

Be used for when the original single pulse of said circuits for triggering output excites, utilizing the miller capacitance C of internal power FET _DgThe diagonal angle capacitor C _GsThe realization self-oscillation of energizing, the power half-bridge self-maintained circuit of output self-oscillation signal, the input of said power half-bridge self-maintained circuit is connected with the output of said circuits for triggering;

Be used for said self-oscillation signal is carried out impedance matching; The filter circuit of the conversion of realization from the low-impedance voltage source to the high impedance constant-current source; The input of said filter circuit is connected with the output of said power half-bridge self-maintained circuit, and the output of said filter circuit is connected with load HID pipe.

2. HID electronic ballast circuit as claimed in claim 1 is characterized in that, said power half-bridge self-maintained circuit comprises:

Transformer T1, upper arm metal-oxide-semiconductor Q7 and underarm metal-oxide-semiconductor Q8;

The end of the same name of the elementary winding N1 of said transformer T1 is that the input of said power half-bridge self-maintained circuit is connected with said circuits for triggering; The different name end ground connection of the elementary winding N1 of said transformer T1; The end of the same name of the said transformer T1 first secondary winding N2 is connected with the control end of said upper arm metal-oxide-semiconductor Q7; The input of said upper arm metal-oxide-semiconductor Q7 connects supply voltage; The output of said upper arm metal-oxide-semiconductor Q7 is that the output of said power half-bridge self-maintained circuit is connected with the different name end of the said transformer T1 first secondary winding N2; The different name end of said transformer T1 second subprime winding N3 is connected with the control end of said underarm metal-oxide-semiconductor Q8; The input of said underarm metal-oxide-semiconductor Q8 is connected with the output of said upper arm metal-oxide-semiconductor Q7, and the end of the same name of the output of said underarm metal-oxide-semiconductor Q8 and said transformer T1 second subprime winding N3 is ground connection simultaneously.

3. HID electronic ballast circuit as claimed in claim 2 is characterized in that, said upper arm metal-oxide-semiconductor Q7 and said underarm metal-oxide-semiconductor Q8 are N type metal-oxide-semiconductor.

4. HID electronic ballast circuit as claimed in claim 2 is characterized in that, said power half-bridge self-maintained circuit also comprises:

Capacitor C 8, capacitor C 9, voltage stabilizing didoe Z1, voltage stabilizing didoe Z2, voltage stabilizing didoe Z3 and voltage stabilizing didoe Z4;

The first secondary winding N2 of said transformer T1 is parallelly connected with said capacitor C 8; Connect relatively back and said capacitor C 8 of said voltage stabilizing didoe Z1 and said voltage stabilizing didoe Z2 negative electrode is parallelly connected; The anode of said voltage stabilizing didoe Z1 is connected with the end of the same name of the first secondary winding N2 of said transformer T1, and the anode of said voltage stabilizing didoe Z2 is connected with the different name end of the first secondary winding N2 of said transformer T1;

The second subprime winding N3 of said transformer T1 is parallelly connected with said capacitor C 9; Connect relatively back and said capacitor C 9 of said voltage stabilizing didoe Z3 and said voltage stabilizing didoe Z4 negative electrode is parallelly connected; The anode of said voltage stabilizing didoe Z3 is connected the plus earth of said voltage stabilizing didoe Z4 with the different name end of the second subprime winding N3 of said transformer T1.

5. HID electronic ballast circuit as claimed in claim 1 is characterized in that, said filter circuit comprises:

Capacitor C 5, capacitor C 6 and inductance L 4, inductance L 5;

One end of said capacitor C 5 is the input of said filter circuit; The other end of said capacitor C 5 is connected with an end of said inductance L 4; The other end of said inductance L 4 is connected with an end of said capacitor C 6; The other end ground connection of said capacitor C 6, said inductance L 4 is connected with an end of said inductance L 5 with the common port of said capacitor C 6, and the other end of said inductance L 5 is the output of said filter circuit.

6. HID electronic ballast circuit as claimed in claim 1 is characterized in that, said filter circuit comprises:

Transformer T3, capacitor C 10, capacitor C 11, capacitor C 12, capacitor C 13, capacitor C 14 and inductance L 6;

One end of said capacitor C 14 is that the input of said filter circuit is connected with the output of said power half-bridge self-maintained circuit; The other end of said capacitor C 14 is connected with the end of the elementary winding N7 of said transformer T3; The other end of the elementary winding N7 of said transformer T3 is connected with an end of said inductance L 6, an end of said capacitor C 12 simultaneously; The other end of said inductance L 6 is the output of said filter circuit; The other end of said capacitor C 12 is through said capacitor C 13 ground connection, and said capacitor C 12 is connected with an end of said capacitor C 10 with the link of said capacitor C 13, and the other end of said capacitor C 10 is connected with the output of circuits for triggering through said capacitor C 11; The end of said transformer T3 secondary winding N8 is the induction power supply end of said filter circuit, the other end ground connection of said transformer T3 secondary winding N8.

7. HID electronic ballast circuit as claimed in claim 1; It is characterized in that; Said ballasting circuit also comprises and is used for taking place when unusual at said ballasting circuit, and the work of the said power half-bridge of force disconnect self-maintained circuit makes said ballasting circuit get into the abnormity protection circuit of guard mode; The input of said abnormity protection circuit is connected with the induction power supply end of said filter circuit, and the control end of said abnormity protection circuit is connected with the unusual control end of said power half-bridge self-maintained circuit.

8. HID electronic ballast circuit as claimed in claim 7 is characterized in that, said abnormity protection circuit comprises:

Capacitor C 15, capacitor C 16, resistance R 3, resistance R 4, resistance R 5, diode D4, diode D5, clamp diode D6, switching tube Q11 and bidirectional trigger diode VD2;

The anode of said diode D4 is the control end of said abnormity protection circuit; The negative electrode of said diode D4 is connected with the input of said switching tube Q11, the output head grounding of said switching tube Q11, and the control end of said switching tube Q11 is through said capacitor C 15 ground connection; Said resistance R 3 is parallelly connected with said capacitor C 15; The end of said bidirectional trigger diode VD2 is connected with the control end of said switching tube Q11, and the other end of said bidirectional trigger diode VD2 is through capacitor C 16 ground connection, and said resistance R 4 is parallelly connected with said capacitor C 16; The other end of said bidirectional trigger diode VD2 also is connected with an end of said resistance R 5; The other end of said resistance R 5 is connected with the negative electrode of said diode D5, and the anode of said diode D5 is the input of said abnormity protection circuit, and said clamp diode D6 is parallelly connected with said resistance R 4; The negative electrode of said clamp diode D6 is connected in the link of said bidirectional trigger diode VD2 and said resistance R 5, the plus earth of said clamp diode D6.

9. an electric ballast is characterized in that, said ballast adopts each described HID electronic ballast circuit of claim 1 to 8.

10. a high-voltage gas discharging light is characterized in that, said high-voltage gas discharging light comprises the described ballast of claim 9.

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