WO2010118626A1

WO2010118626A1 - Electronic ballast for a fluorescent lamp and an energy-saving lamp

Info

Publication number: WO2010118626A1
Application number: PCT/CN2010/000318
Authority: WO
Inventors: 张玉清
Original assignee: Zhang Yuqing
Priority date: 2009-04-14
Filing date: 2010-03-15
Publication date: 2010-10-21
Also published as: CN101868106A

Abstract

The present invention relates to an electronic ballast for a fluorescent lamp and an energy-saving lamp. A multi-function module MK circuit is added to the electronic ballast which is based on a half-bridge inverter circuit. The multi-function module MK circuit, which is connected between a positive node A and negative node B of a power supply of a rectifier filter circuit and an upper and a lower bridge of two power tubes, has functions of preventing the upper and lower bridge from being on at the same time, stating preheating, over current and short-circuit protection. Although the cost is increased, the electronic ballast can be a new generation half-bridge inverter circuit electronic ballast which has long use life, relatively low cost, sufficient output power and has the functions of electronic preheating, over current and short-circuit protection. The invention helps to promote and popularize split type energy-saving lamps, end the situation that previous fluorescent lamps and energy-saving lamps save energy without saving money, and further helps to reduce the emission of carbon dioxide and the environment pollution caused by mercury.

Description

Electronic ballast for fluorescent lamp and energy saving lamp

Technical field:

The invention belongs to the technical field of electric lighting, and further relates to "an electronic ballast for fluorescent lamps and energy-saving lamps".

Background technique:

In the existing technology: "Fluorescent lamp and energy-saving lamp electronic ballast" currently used in the market and commonly used by consumers

(Note: hereinafter referred to as "electronic ballast"), basically the circuit structure using "magnetic saturation self-excited half-bridge inverter" (Note: hereinafter referred to as "half-bridge inverter") As shown in Figure 1); due to its simple structure, fewer components, and lower price, it is especially popular among consumers; however: This electronic ballast has poor anti-interference ability and no overcurrent and Short-circuit protection function, so there is a damage rate of 10~20% or more every year; and because there is no preheating function, the "sunlight tube and energy-saving lamp tube" (hereinafter referred to as "lamp") The service life is severely shortened, especially when the ambient temperature is below + io°c, the service life of the lamp is shortened more obviously; therefore, the manufacturer has to reduce the output power of the ballast to the rated power of the lamp to be lit. 60~70%, to reduce the impact on the filament of the lamp during startup, to prolong the service life of the lamp. As a result, the brightness of the lamp illuminated by the ballast is obviously insufficient; but it cannot be avoided every year. Big The amount of electronic waste and discarded lamps, especially the heavy metal mercury in a large number of discarded lamps, is environmentally harmful and harmful to future generations; now it has the functions of starting preheating, open circuit, overcurrent and short circuit protection. The electronic ballasts are composed of dedicated integrated circuits and field effect power tubes. Because of the high cost, the price is relatively expensive and is not accepted by consumers.

Summary of the invention:

In order to overcome the above disadvantages: The present invention provides a "multi-function module MK" based on a half-bridge inverter circuit: This module has "preventing an accidental simultaneous and instantaneous power tube of a half-bridge inverter simultaneously Turn on and burn out" (Note: hereinafter referred to as "anti-co-guide"), start preheating, overcurrent and short circuit protection; although adding a little cost, it can make this electronic ballast extremely reliable and cost-relative Lower generation, ample output power and a new generation of electronic ballasts with multiple protection functions; the relative brightness of the lamps illuminated by the electronic ballast is significantly increased, and the service life of the lamps is extended by 3 to 5 times. The above advantages.

Technical solutions:

The technical solution of the present invention comprises: a triode, a thyristor, a diode, a resistor, a capacitor, an electrolytic capacitor, a transformer and an inductor; and the following features: a rectifying and filtering circuit, an open circuit protection and trigger circuit, and a half bridge inverter circuit The series resonant output circuit and the multi-function module MK circuit are composed; wherein the "multi-function module MK circuit" (Note: hereinafter referred to as "module MK") is connected to the positive power supply node A and the negative power supply node B of the rectifying and filtering circuit. The upper and lower bridges of the two power tubes of the bridge inverter (shown in Figure 2). The specific technical solutions of the present invention are shown in FIG. 2 and FIG. 3:

The rectifying and filtering circuit comprises: a diode D 1 D4 and an electrolytic capacitor C1; the diodes D1 to D4 form a bridge rectifier, wherein a cathode of the diode D1 is connected to a cathode of the diode D2 and is connected to an input terminal X of the alternating current power source. The cathode of the diode D3 is connected to the anode of the diode D4 and is connected to the other input terminal 0 of the alternating current power source; the node A of the anodes of the diodes D1 and D3 and the anode of the electrolytic capacitor C1 are positive. The node B connected to the negative electrode of the diodes D2 and D4 and the negative electrode of the electrolytic capacitor C1 is negatively charged.

The open circuit protection and trigger circuit comprises: a resistor R1 R2, a diode D5, a capacitor C2 and a trigger diode DR: one end of the resistor R1, one end of the resistor R2 and one end of the capacitor C5 and one end of the lamp tube One end of the filament is connected; the other end of the resistor R1 is connected to the cathode of the diode D5, one end of the trigger diode DR, and one end of the capacitor C2; the other end of the resistor R2 and the anode of the diode D5, one end of the resistor R3 The module MK pin 2, the negative terminal of the diode D6, the end of the capacitor C4, the head end of the primary winding a of the magnetic saturation transformer T, and the tail end of the secondary winding b of the magnetic saturation transformer T are connected (Note: In order to distinguish the direction of the primary and secondary windings of the magnetic saturation transformer T, the dotted end is the winding end and the other end is the winding tail according to the convention; the other end of the trigger diode DR and the base of the transistor BG2, the diode D7 The positive electrode is connected to one end of the resistor R6; the other end of the capacitor C2 has one end of the resistor R7, the negative electrode of the electrolytic capacitor C3, and the module MK pin 7 Flow filter circuit node B is connected to negative charge.

The half-bridge inverter circuit comprises: a transistor BG1~BG2, a diode D6~D7, a resistor R3 R6 and a magnetic saturation transformer T; the collector of the transistor BG1 and the other end of the capacitor C4, the lamp DG- The other end of the filament is positively connected to the node A in the rectifying and filtering circuit, the base of the transistor BG1 is connected to the anode of the diode D6, one end of the resistor R4 and the module MK pin 3, and the emission of the transistor BG1 The pole is connected to the other end of the resistor R3; one end of the resistor R3 is connected to the anode of the diode D5, the other end of the resistor R2, the module MK pin 2, the cathode of the diode D6, the end of the capacitor C4, and the magnetic saturation transformer. The first end of the primary winding a of T is connected to the tail end of the secondary winding b of the magnetic saturation transformer T; the other end of the resistor R4 is connected to the leading end of the secondary winding b of the magnetic saturation transformer T; The collector of the transistor BG2 is connected to the MK pin 5 of the module, the base of the transistor BG2 is connected to the anode of the diode D7, the end of the resistor R6 and the other end of the trigger diode DR; the hair of the transistor BG2 The pole is connected to one end of the resistor R5, and the other end of the resistor R5 is opposite to the cathode of the diode D7, the resistor R7, the anode of the electrolytic capacitor C3, the module MK pin 6, and the head end of the secondary winding c of the magnetic saturation transformer T. The other end of the resistor R6 is connected to the tail end of the secondary winding c of the magnetic saturation transformer T.

The series resonant output circuit comprises: an inductor L, capacitors C5 C C6 and a filament at both ends of the external lamp tube DG; one end of the inductor L is connected to the tail end of the primary winding a of the magnetic saturation transformer T, the inductor The other end of L One end of the capacitor C6 is connected, the other end of the capacitor C6 is connected to one end of the filament of the other end of the outer circuit tube DG, and the other end of the filament of the other end of the tube DG is connected to one end of the capacitor C5, the capacitor C5 The other end is connected to the other end of the filament of the lamp DG-end, and the other end of the filament of the lamp DG-end is positively connected to the node A in the rectifying and filtering circuit.

The multi-function module circuit MK includes: an anti-co-transmission circuit, a start preheating circuit, and an overcurrent and short-circuit protection circuit, and externally set a total of 7 pins from 1 to 7; the module MK has a pin 1 and the The node A in the rectifying and filtering circuit is positive, the collector of the transistor BG1, the other end of the capacitor C4, and the other end of the filament of the lamp DG are connected; the pin 2 of the module MK and the anode of the diode D5, The other end of the resistor R2, the other end of the resistor R3, the cathode of the diode D6, the other end of the capacitor C4, the head end of the primary winding a of the magnetic saturation transformer, and the tail end of the secondary b of the magnetic saturation transformer are connected; The pin 3 of the module MK is connected to the base of the transistor BG1 of the bridge inverter circuit, the anode of the diode D6, and one end of the resistor R4; the pin 4 of the module MK and the bridge inverter circuit The other end of the resistor R4 is connected to the head end of the secondary winding b of the magnetic saturation transformer T; the pin 5 of the module MK is connected to the collector of the transistor BG2 in the half-bridge inverter circuit; Said module MK pin 6 and The positive terminal of the decoupling capacitor C3, the other end of the resistor R7, the other end of the resistor R5, the anode of the diode D7, and the head end of the secondary winding c of the magnetic saturation transformer T are connected; the pin 7 of the module MK and the resistor One end of the device R7, the negative electrode of the electrolytic capacitor C3, and the node B in the rectifying and filtering circuit are negatively connected.

The internal circuit of the multi-function module MK is as shown in FIG. 3: comprising a transistor, a thyristor, a diode, a resistor, a capacitor and an electrolytic capacitor; the specific function of the multi-function module MK is activated by an anti-co-channel Preheating circuit and overcurrent, short circuit protection circuit.

The anti-co-transmission routing transistors BG3 B BG4, diodes D8 D D9, resistors R8 R R11, and capacitor C7 are formed; the emitter of the triode BG3 is connected to one end of the resistor R10 and the MK pin 3 of the module (Note: The transistor BG3 is a PNP type transistor, and the rest are NPN type transistors. The base of the transistor BG3 is connected to the other end of the resistor R10, one end of the resistor R11 and one end of the capacitor C7, and the collector and the resistor of the transistor BG3. One end of the device R8, the negative electrode of the diode D8, the positive electrode of the diode D12, one end of the capacitor C10 and the MK pin 2 of the present module are connected; the collector of the transistor BG4 is connected to the other end of the capacitor C7 and the other end of the resistor R11. The base of the transistor BG4 is connected to the other end of the resistor R8 and the end of the resistor R9; the emitter of the transistor BG4 and the other end of the resistor R9, the anode of the diode D9, the cathode of the diode D11, and the anode of the diode D10. One end of the resistor R12 is connected to the pin 5 of the module; the anode of the diode D8 and the cathode of the diode D9 Connection.

The startup preheating circuit is composed of a transistor BG5, a diode D10, resistors R12 to R14, an electrolytic capacitor C8, capacitors C9 to C10, and resistors R10 to R11, a capacitor C7 and a transistor BG3 in the anti-coherence circuit; The anode of the electrolytic capacitor C8 is connected to the lead 4 of the module, the cathode of the electrolytic capacitor C8 is connected to one end of the resistor R14, the other end of the resistor R14 is connected to the base of the transistor BG5, and the resistor R13. One end is connected to one end of the capacitor C9; the emitter of the transistor BG5 is connected to the negative terminal of the diode D10, the other end of the resistor R12, the other end of the resistor R13, the other end of the capacitor C9, and the other end of the capacitor C10.

The overcurrent and short circuit protection circuit: by thyristor QT, diode Dl l, resistor R15~R16, electrolytic capacitor

C11, the light emitting diode DL and the anti-conduction circuit are jointly formed; one end of the resistor R16 is connected with the pin 6 of the module, the other end of the resistor R16 is opposite to the positive electrode of the electrolytic capacitor C11 and the trigger pole of the thyristor QT Connected, the cathode of the electrolytic capacitor C11 is connected to the cathode of the thyristor QT, the cathode of the diode D12, and the lead 7 of the module; the anode of the thyristor QT and the anode of the diode D11 and the anode of the LED DL Connected, the negative terminal of the LED DL is connected to one end of the resistor R15, and the other end of the R15 of the resistor is connected to the pin 1 of the module. The beneficial effects of the present invention are:

The electronic ballast has anti-co-conversion, start-up preheating, open circuit, overcurrent and short circuit protection functions; although the addition of a small cost does significantly change the inherent disadvantages of the original electronic ballast; the electronic ballast has an electronic pre- Advantages of heat, dry resistance, sufficient drive power and extremely low damage (even if the output is short-circuited, the electronic ballast will not be damaged), and the illuminated lamp can be compared to the original electronic ballast. The brightness of the lamp with the same power is obviously increased, so that the life of the lamp tube is relatively increased to 3~5 times or more; the electronic ballast of the invention has high cost performance and strong market competitiveness, and has better performance. Social and environmental benefits are also conducive to the production and popularization of "separate energy-saving lamps", and are more conducive to reducing carbon dioxide gas emissions and environmental pollution caused by heavy metal mercury.

The present invention is further described below in conjunction with the accompanying drawings and embodiments:

Figure 2 is a schematic diagram of the overall circuit of the present invention;

Figure 3 is a schematic diagram of the circuit of the MK part of the multifunctional module of the present invention;

The structure and working principle of the present invention will be briefly described below with reference to FIG. 2:

As shown in FIG. 2: The invention is "a fluorescent ballast and an energy-saving lamp electronic ballast" mainly composed of a rectifying and filtering circuit, an open circuit protection and trigger circuit, a half bridge inverter circuit, a series resonant output circuit and a multifunctional module. The rectifier circuit, the open circuit protection and trigger circuit, the half bridge inverse transformer circuit and the series resonant output circuit are all prior art, and the working principle thereof is not described herein.

The structure and principle of the multi-function module portion of the "one fluorescent lamp and the energy-saving lamp electronic ballast" of the present invention will be further described in detail below with reference to some of the electronic components of Figs. 3 and 2.

The multi-function module MK: is composed of an anti-co-transmission circuit, a start preheating circuit, and an overcurrent and short circuit protection circuit.

The anti-co-conductive routing transistors BG3 B BG4, diodes D8 D D9, resistors R8 R R11 and capacitor C7 The specification comprises: when the half-bridge inverter circuit works in the positive half cycle output, the transistor BG1 is turned on, and the transistor BG2 is turned off; at this time, no current passes through the module pin 2 through the diodes D8, D9 and the resistors R8, R9 Flow to module pin 5, so the voltage between module pin 2 and module pin 5 is 0 volts; between resistors R8, R9 connected in series with the base of the transistor BG4 and the module pin 5 The voltage is also 0 volts; at this time, the transistor BG4 is turned off, because the base voltage of the transistor BG3 is equal to the voltage of the pin 3 of the module under the action of the resistor R10, and the emitter of the transistor BG3 is also connected with the pin 3 of the module. Connected, so the voltage between the emitter and the base of the transistor BG3 is equal to 0 volts; the transistor BG3 is turned off, so the transistor BG3 has no effect on the working state of the transistor BG1 when the half-bridge inverter circuit operates at the positive half cycle output. When the half-bridge inverter circuit works in the negative half-cycle output, the transistor BG1 is turned off and the transistor BG2 is turned on; at this time, the current flows through the diodes D8 and D9 of the module and the resistors R8 and R9 respectively. Module 5 pin, since diodes D8 and D9 are connected in series in the forward direction, and since diodes D8 and D9 are selected as ordinary silicon rectifier tubes with a forward junction voltage drop of 0.6 volts, the voltage between pin 2 and pin 5 is stabilized. 1.2 volts or so; module pin 2 is relatively positive voltage, module pin 5 is relatively negative voltage; and because resistors R8, R9 are connected in series, properly select the resistance of resistors R8, R9, so that resistors R8, R9 After the series connection, the voltage between the node voltage connected to the base of the transistor BG4 and the voltage between the module pins 5 is slightly higher than 0.6 volts, so that the transistor BG4 is turned on; after the transistor BG4 is turned on, the collector voltage is approximately equal to the module pin. The voltage of 5 is applied to the base of the transistor BG3 through the current limiting resistor R11 and the accelerating capacitor C7. This voltage is a forward voltage with respect to the base of the PNP type transistor BG3, and the transistor BG3 is turned on; thus the emission of the transistor BG3 The voltage between the terminal pin 3 and the collector, that is, the module pin 2 is approximately equal to 0 volts, and since the module pin 2 is connected to the other end of the emitter resistor R3 of the half bridge inverter circuit BG1, Module pin 3 and half bridge The base of the inverter transistor BG1 is connected. If a positive current with interference is applied to the base of the half-bridge inverter BG1, it will be short-circuited by the emitter and collector of the transistor BG3 in the module. Therefore, when the transistor BG2 of the half-bridge inverter is turned on, the half-bridge inverter transistor BG1 is forcibly turned off by the anti-co-transmission circuit; that is, the transistors BG1 and BG2 of the half-bridge inverter are anti-co-guided. Under the action of the circuit, it will not be instantaneously turned on and damaged in any working state.

The startup preheating circuit is composed of a triode BG5, resistors R12 to R14, an electrolytic capacitor C8, capacitors C9 to C10, and a triode BG3, a resistor R10 to R11, and a capacitor C7 in the anti-coherence circuit; Before the transformer starts, the voltage between the electrolytic capacitor C8 and the capacitor C10 is equal to 0 volts; when the bridge inverter is started, it first enters the negative half-cycle output state, the transistor BG1 is turned off, the transistor BG2 is turned on, and the current is passed by the rectifying and filtering circuit. The positive electrode of node A is filament "flow direction" at one end of lamp DG (Note: the following is represented by "one") Capacitor C5 - filament at the other end of lamp DG - capacitor C6 → inductor L → magnetic The primary winding a of the saturating transformer enters the multi-function module via module pin 2 and is divided into three ways: one through diode D8-D9 to pin 5, the other through resistor R8-R9 to pin 5, and one via capacitor C10-diode D10 flows to module pin 5, and then rectifies via transistor BG2 - resistor R5 - resistor R7 - In the filter circuit, the node B is negatively charged; in this process, the capacitor C5 and the capacitor C10 are respectively charged; the capacitor C10 is connected to the module pin 2 terminal is positive, and the capacitor C10 is connected to the diode D10 positive terminal is negative; The voltage induced at the head end of the secondary winding b of the magnetic saturation transformer T connected to the pin 4 is a negative voltage, and the voltage induced at the terminal end of the secondary winding b of the magnetic saturation transformer T is positive voltage, relative to the diode D10 And the transistor BG5 emitter junction are reverse voltage, so the current can not be reversed by the module pin 2 → resistor R8 → resistor R9 → diode D10 - transistor BG5 emission junction an electrolytic capacitor C8 and module pin 4 against the electrolytic capacitor C8 Charging or discharging; Because the operating frequency of the bridge inverter is relatively high, the resistance values of the resistors R12 and R13 are relatively large, which has little effect on the reverse charging and discharging process of the capacitor C10, which can be ignored; When the negative half cycle output of the inverter enters the positive half cycle output: the transistor BG2 is turned off, and the transistor BG1 cannot be turned on immediately under the action of the start preheating circuit. The device C5巳 starts to discharge, and its positive current passes through one end of the series resonant capacitor C5, and the other end of the lamp DG is a capacitor C4 (Note: Since the capacity of the capacitor C4 is small, a part of the current flows through the electrolytic capacitor C1 - the module pin 7 →Diode D12—module pin 2→magnetic saturation transformer T primary winding a)—magnetic saturation transformer T primary winding a—series resonant inductor L→capacitor C6—lamp DG end filament one end of series resonant capacitor C5; The tail end of the secondary winding c of the magnetic saturation transformer T is induced to be a negative voltage. This negative voltage is applied to the base of the transistor BG2 via the resistor R6 to keep the transistor BG2 off; the tail of the secondary winding b of the magnetic saturation transformer T The terminal sense is negative, and the first end is induced as a positive voltage; this positive voltage is applied to the base of the transistor BG1 via the resistor R4, and is applied to the BG5 base of the triode through the pin 4 of the multi-function module - the electrolytic capacitor C8 → the resistor R14 Extremely, the transistor BG5 is turned on; at the same time, the electrolytic capacitor C8 is charged. Due to the large capacity selected by the electrolytic capacitor C8 and the current limiting action of the resistor R14, only a small amount of electricity can be charged in each positive half cycle. And because capacitor C10 is charged during the first negative half cycle of the half-bridge inverter; capacitor C10 is connected to the positive terminal of diode D10 to be negatively charged, this voltage of capacitor C10 and the tail of secondary winding b of magnetic saturation transformer T The terminal induction is a negative electric phase superposition; for the base of the PNP type triode BG3, it is a forward current. When the triode BG5 is turned on, this negative voltage is applied to the base of the triode BG3 via the resistor R11 and the capacitor C7, so that the triode BG3 is guided. The transistor BG3 is turned on to make the voltage between the module pin 2 and the module pin 3 close to 0 volts, which is equivalent to the voltage between the base and the emitter of the transistor BG1 is equal to 0 volt, forcing the transistor BG1 in the half bridge inverter When the capacitor C10 is discharged, the base of the PNP transistor BG3 loses the negative voltage and is turned off. At this time, the positive voltage induced at the head end of the secondary winding b of the magnetic saturation transformer T can be normal. The resistor R4 is applied to the base of the transistor BG1 to make the conduction of the transistor BG1 relatively delayed (appropriate selection of the capacity of the capacitor C10, which can change the positive half-cycle of the bridge inverter in the bridge inverter BG1 Since the time during which the transistor BG1 is turned on in the positive half cycle is relatively shortened, the output power of the entire bridge inverter is relatively reduced, and the appropriate selection of the starting power does not have an impact on the filament of the lamp but instead It can play the role of preheating; when the electronic inverter is started, the bridge inverter charges the capacitor C10 every negative half cycle output, and discharges in the appropriate time during each positive half cycle output, electrolysis Capacitor C8 is charged every positive half cycle, and does not discharge during negative half cycle. When the voltage charged by electrolytic capacitor C8 is equal to the positive voltage induced at the head end of secondary winding b of magnetic saturation transformer T, electrolytic capacitor C8 The charging current will not be generated again, so that the triode BG5 and the triode BG3 are no longer turned on. At this time, the electronic ballast starts the preheating process, and the bridge inverter enters the normal output working state; the capacitor C7 accelerates in the circuit. Function, capacitor C9 acts as a high-frequency voltage bypass in the circuit; when the illumination is turned off and the AC power is turned off, the positive voltage charged by the positive electrode of the electrolytic capacitor C8 passes through the secondary winding b of the magnetic saturation transformer T—module pin 2 →Resistors R8, R9→Resistors R12→Resistors R13→Resistors R14 are discharged to the negative pole of electrolytic capacitor C8. The entire discharge time is about ten seconds. During this time, if the lamp is re-lighted, although it starts up The preheating circuit cannot fully exert its function of starting the preheating process, but since the temperature of the lamp tube and the filament is not completely cooled, the service life of the lamp tube is Big impact.

C11 and LED DL; When the bridge inverter works in normal state, a DC voltage will be generated across the resistor R7. This DC voltage is filtered by the electrolytic capacitor C3 and then passed through the second leg of the module MK. R16 and electrolytic capacitor C10 are filtered and applied to the control electrode of the thyristor; the resistance value of the resistor R7 is appropriately selected so that the voltage value generated is appropriately lower than the trigger voltage of the thyristor QT control electrode, so that the thyristor In the off state; since one end of the resistor R15 is positively connected to the node A in the rectifying and filtering circuit via the module pin 1, the other end of the resistor R15 is connected to the negative electrode of the LED DL, the positive electrode of the LED and the thyristor The anode is connected to the anode of the diode D11 such that the voltage of the anode of the diode D11 is approximately equal to the positive voltage of the node A in the rectifier filter circuit; since the cathode of the diode D11 is always less than or equal to the positive voltage of the node A, the diode D11 is also Keeping the off state all the time; since the thyristor QT and the diode D11 are both in the off state, the light emitting diode DL has no current to pass without emitting light; When the load power of the output circuit increases significantly or short circuit, the DC voltage drop of the resistor R7 will increase at the same time. When the voltage across the resistor R7 is higher than the trigger voltage of the thyristor QT control electrode, the thyristor QT will be made via the resistor R16. When the thyristor QT is turned on, its anode voltage is equal to 0 volts relative to the module pin 7 and the junction B voltage in the rectifying and filtering circuit, so that the diode D11 is forward-conducting, so that the voltage of the pin 5 and the lead The voltage of the foot 7 is also close to 0 volts; by the action of the anti-communication circuit described above, the transistor BG1 of the bridge inverter is immediately cut off, so that the entire bridge inverter works completely to stop the protection; After the converter stops outputting, there is no current passing across the resistor R3 and the voltage drop is equal to 0 volts. Since the current flowing through the resistors R1 and R2 through the diode D11 and the thyristor QT is very small, it is possible to cause the thyristor QT to exit. Inductive state; In order to prevent the thyristor QT from exiting the conduction state and causing the bridge inverter to start again and be damaged, the positive voltage of the node A of the rectifying and filtering circuit is connected to the light-emitting diode DL to provide the thyristor QT. One maintains electricity The flow causes the thyristor QT to maintain a stable conduction state, and the light-emitting diode DL emits light, prompting the consumer to enter the protection state of the electronic ballast ;; if the power supply is disconnected under the protection state, the electrolytic capacitor in the rectification and filtering circuit While the amount of electricity stored in C1 is gradually decreasing, the maintenance of thyristor QT The current of the specification is also gradually reduced. When the holding current of the thyristor QT is less than a certain value, it will exit the conduction state and be cut off, so that the overcurrent and short circuit protection circuits of the module are restored to the normal working state of the electronic ballast; The process can effectively protect the electronic ballast from being damaged when there is overcurrent or short circuit at the output.

Specific embodiment:

2 and FIG. 3 are also actual circuit schematic diagrams of the embodiment; the electronic component connection relationship according to the circuit schematic diagram of FIG. 2 and FIG. 3 and the appropriate selection of the electrical performance parameters of each electronic component can be produced. Different power fluorescent lamps and energy-saving lamp electronic ballasts.

The multi-function module MK (Fig. 3) can be formed on a circuit board by using the discrete components and the components shown in Fig. 2, or the multi-function module MK can be made into a thick film circuit and an integrated circuit, and then the drawing. The components shown in Fig. 2 are fabricated on a circuit board, which significantly reduces the volume of the electronic ballast of the present invention and provides more reliable performance.

The power output tubes BG1 and BG2 of the bridge inverter can be replaced by bipolar transistors or field effect transistors (MOSFETs) and insulated gate bipolar transistors (IGBTs).

The multi-function module MK can be widely applied to electronic products having a bridge inverter output circuit.

Claims

Claim

1 . An electronic ballast for fluorescent lamps and energy-saving lamps: an electronic ballast based on a circuit structure of a magnetic saturation self-excited bridge inverter, comprising a triode, a thyristor, a diode, a resistor, a capacitor, and an electrolysis The capacitor, the transformer and the inductor are composed of: a multi-function module circuit MK consisting of an anti-co-transmission circuit, a start preheating circuit, an overcurrent and a short circuit protection circuit, and a positive power supply node A and a negative connected to the rectifying and filtering circuit The power node B and the upper and lower bridges of the two power tubes of the magnetic saturation bridge inverter.

The multi-function module circuit MK includes an anti-co-transmission circuit, a start preheating circuit, and an overcurrent and short-circuit protection circuit. According to the circuit connection relationship module MK, 1, 2, 3, 4, 5, 6, and 7 are temporarily set. Pins.

The pin 1 of the multi-function module circuit MK is connected to the node A of the rectifier filter circuit, the collector of the transistor BG1, the other end of the capacitor C4, and the other end of the filament of one end of the lamp DG; The pin 2 of the multi-function module circuit MK is opposite to the anode of the diode D5, the other end of the resistor R2, the other end of the resistor R3, the cathode of the diode D6, the other end of the capacitor C4, and the primary winding a of the magnetic saturation transformer. The head end is connected to the tail end of the secondary b of the magnetic saturation transformer; the pin 3 of the multi-function module circuit MK and the base of the transistor BG1 of the bridge inverter circuit, the anode of the diode D6, and the resistor R4 One end is connected; the pin 4 of the multi-function module circuit MK is connected to the other end of the resistor R4 in the bridge inverter circuit and the head end of the secondary winding b of the magnetic saturation transformer T; The pin 5 of the module circuit MK is connected to the collector of the transistor BG2 in the half bridge inverter circuit. The pin 6 of the multi-function module circuit MK is opposite to the anode of the electrolytic capacitor C3, the other end of the resistor R7, the other end of the resistor R5, the anode of the diode D7, and the tail end of the secondary winding c of the magnetic saturation transformer T. The pin 7 of the multi-function module circuit MK is connected to one end of the resistor R7, the negative electrode of the electrolytic capacitor C3, and the node B in the rectifying and filtering circuit.

The anti-co-transmission routing transistors BG3, BG4, diodes D8, D9, resistors R8, R9, R10, Rl l, and capacitor C7 are formed.

The emitter of the transistor BG3 is connected to one end of the resistor R10 and the pin 3 of the multi-function module circuit MK (Note: the transistor BG3 is a PNP type transistor, and the rest are NPN type transistors), and the base of the transistor BG3 Connected to the other end of the resistor R10, one end of the resistor R11, and one end of the capacitor C7, the collector of the transistor BG3 and one end of the resistor R8, the cathode of the diode D8, the anode of the diode D12, the end of the capacitor C10, and the end of the capacitor C10 The function module circuit MK pin 2 is connected.

The collector of the transistor BG4 is connected to the other end of the capacitor C7 and the other end of the resistor R11, the base of the transistor BG4 is connected to the other end of the resistor R8 and the end of the resistor R9, and the emitter of the transistor BG4 is The other end of the resistor R9, the anode of the diode D9, the cathode of the diode D11, the anode of the diode D10, and one end of the resistor R12 are connected to the multi-function module circuit MK pin 5. The anode of the diode D8 is connected to the cathode of the diode D9.

The start preheating circuit: a transistor BG5, a diode D10, resistors R12, R13, R, 14, an electrolytic capacitor C8, capacitors C9, C10, and resistors R10, R11, a capacitor C7 and a triode in the anti-coherence circuit BG3 composition.

The anode of the electrolytic capacitor C8 is connected to the pin 4 of the multi-function module circuit MK, and the negative of the electrolytic capacitor C8 Claim

The pole is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the base of the transistor BG5, one end of the resistor R13, and one end of the capacitor C9.

The emitter of the transistor BG5 is connected to the cathode of the diode D10, the other end of the resistor R12, the other end of the resistor R13, the other end of the capacitor C9, and the other end of the capacitor C10.

The overcurrent and short circuit protection circuit: by thyristor QT, diode Dl l, resistor R15, R16, electrolytic capacitor

C11, the light emitting diode DL and the anti-common circuit are combined.

One end of the resistor R16 is connected to the pin 6 of the multi-function module circuit MK, and the other end of the resistor R16 is connected to the anode of the electrolytic capacitor C11 and the trigger pole of the thyristor QT, and the cathode of the electrolytic capacitor C11 is The cathode of the silicon controlled QT, the cathode of the diode D12 and the MK pin 7 of the multifunction module circuit are connected.

The anode of the thyristor QT is connected to the anode of the diode D11 and the anode of the LED DL, the cathode of the LED DL is connected to one end of the resistor R15, and the other end of the resistor R15 is connected to the multifunction module circuit MK. Pin 1 is connected.

2. A fluorescent lamp and an energy-saving lamp electronic ballast according to claim 1, wherein: said bridge inverter is a self-excited, excited half-bridge or full-bridge reverse transformer.

3. A fluorescent lamp and an energy-saving lamp electronic ballast according to claim 1, wherein: said power tube is a bipolar transistor, a field effect transistor (MOSFET), and an insulated gate bipolar transistor (IGBT).

4. The electronic ballast for a fluorescent lamp and an energy-saving lamp according to claim 1, wherein: the anti-co-transmission circuit of the multi-function module circuit MK, the start preheating circuit, and the overcurrent and short circuit protection circuit.

5. A fluorescent lamp and an energy-saving lamp electronic ballast according to claim 1, wherein: said multi-function module circuit MK circuit can be a discrete component circuit, a thick film circuit or an integrated circuit.