CN2305827Y

CN2305827Y - Electronic ballast

Info

Publication number: CN2305827Y
Application number: CN 96251096
Authority: CN
Inventors: 周京生
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-12-30
Filing date: 1996-12-30
Publication date: 1999-01-27
Anticipated expiration: 2006-12-30

Abstract

The utility model relates to an electronic ballast, which belongs to the technical field of electronic technology. The utility model comprises a filtering rectification circuit and an oscillator. The utility model is characterized in that the utility model is also comprises a load fault protection circuit and a pulse amputator. The load fault protection circuit is formed by that a coupling winding (L5) wound in series around an output transformer (T1) and a choke coil (L3), a negative peak rectifying straight diode (D 6), negative peak threshold voltage detection time-delay circuits (D11, R14, C10), three stage DC amplifying circuits (BG9, BG8, BG6), and an electronic switch (BG4) are orderly connected. The pulse amputator is composed of a transistor (BG5), a limiting resistor (R11) connected in series on a base pole of the transistor, a blocking capacitor (C6), and a discharge diode (D10) bridged and connected with the base pole and an emitter of the transistor (BG5).

Description

A kind of novel electron ballast

The utility model relates to electronic technology field, and a kind of electronic ballast device is used for starting and lights gaseous discharge lamp bulb or fluorescent tubes such as high-pressure mercury lamp, sodium vapor lamp, fluorescent lamp.

In the prior art, the large-power lamp that is used for the public place is still in the majority with sense formula ballast, has only the civilian fluorescent lamp of part (also claiming fluorescent lamp) to use electric ballast.Existing sense formula ballast is not only heavy, and will expend a large amount of silicon steel and copper material; Existing electric ballast base is two-tube LC series resonant circuit on not, needs to use two high-power switch tubes, and employed protective circuit is the special chip of external import; circuit complexity not only; the cost height, and the impulse current of being exported when starting is big, influences the useful life of fluorescent tube.

In view of there are above-mentioned many deficiencies in prior art, the purpose of this utility model is to provide a kind of novel electron ballast, and this ballast all uses discrete component, and circuit is simple, and it is little to start impulse current, the fluorescent tube long service life.

The utility model realizes that the technical solution of above-mentioned purpose comprises filter rectifier, transformer coupled feedback bikini oscillator, current-limiting circuit, it is characterized in that also comprising load fault protection circuit and pulse ablates device, described load fault protection circuit is by the coupling coil of string on output transformer and the choke, negative peak straightening diode, the negative peak threshold voltage detects delay circuit, three grades of dc amplification circuits and electronic switch be connected successively form, described negative peak threshold voltage detects delay circuit by the voltage stabilizing didoe on the first order amplifying triode base stage that is serially connected in dc amplification circuit, the integrating circuit of this transistor base of resistance and cross-over connection and emitter constitutes, described electronic switch is made of triode, the collector and emitter of this triode is connected across on the base stage and emitter of the oscillating tube in the described bikini oscillator, the feedback signal shorted to earth during with load faulty; Described pulse ablates device by triode and be serially connected in current-limiting resistance, the capacitance on this transistor base and be connected across transistor base and emitter on discharge diode form, the base stage of described triode links to each other with the input of described bikini oscillator with current-limiting resistance through capacitance, the base stage of the oscillating tube in collector electrode and the bikini oscillator links to each other, grounded emitter is with spike forward position excision in the feedback signal.

Above-mentioned technical solution of the present utility model has following outstanding advantage and effect than prior art:

1. be provided with the load fault protection circuit, both reduced no-load loss, make ballast self obtain protection again;

2. be provided with the pulse ablates device, the thermal losses of oscillating tube greatly, impulse current is little during startup, has prolonged the useful life of fluorescent tube or bulb;

3. all use common discrete electronic component, help domestic manufacturers' development and use;

4. circuit structure is simple, and is with low cost.

Below in conjunction with drawings and Examples the utility model is explained in further detail,, grasps better and implement technological means of the present utility model so that the public fully understands technical solution described in the utility model;

5. the required voltage-current characteristic of the output characteristic of circuit and gaseous discharge lamp adapts substantially;

6. change circuit main element ginseng and can obtain different inverter powers.

Description of drawings:

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

Fig. 2 separates the electrical schematic diagram of the designed 150W sodium lamp ballast of scheme for using technology described in the utility model.

Embodiment:

Referring to Fig. 2, bridge rectifier and filter capacitor C2 that described filter rectifier comprises in the common inverter that is made of coil L1, L2 on same magnetic core and capacitor C 1 filter circuit commonly used, is made up of rectifier diode D1-D4.Described transformer coupled feedback bikini oscillator is a core with switch triode BG3, the primary coil of the output transformer T1 that on its collector electrode, be provided with choking-winding L3, connects with choking-winding L3 and with the resonant capacitance C4 of the parallel connection of primary windings of choking-winding L3 and output transformer T1; On its base stage, be serially connected with current-limiting resistance R10 successively and every straight coupling capacitance C7; Cross-over connection has discharge diode D7 on its base stage and emitter; Feedback coil L4 is connected across the emitter of triode BG3 and on the positive pole of straight coupling capacitance C7.Described feedback coil L4 is divided into two sections strings on the magnetic core of output transformer T1 and choking-winding L3, its objective is in order to improve the stability of fluorescent tube or bulb starter front and back feedback signal.The high-frequency signal of described feedback coil L4 output provides DC power supply for triode BG8, BG9 in the direct current amplifier through diode D9 rectification after capacitor C 9 filtering.

Referring to Fig. 2, described load fault protection circuit detects delay circuit D11, R14, C10, three grades of dc amplification circuit BG9, BG8, BG6 and electronic switch BG4 by string around coupling coil L5, negative peak straightening diode D6, negative peak threshold voltage on output transformer T1 and the choke L3 and is connected institute successively and forms; Wherein negative peak threshold voltage detection delay circuit is made of the integrating capacitor C10 on voltage stabilizing didoe D11 resistance R 14 and this transistor base of cross-over connection and the emitter on the first order amplifying triode BG9 base stage that is serially connected in dc amplification circuit, described electronic switch is made of triode BG4, the collector and emitter of this triode is connected across on the base stage and emitter of the oscillating tube in the described bikini oscillator, and shorted to earth is believed in the feedback of sending out during with load faulty.In order to prolong the shutoff action time of triode BG4, to capacitor C 4 chargings, establish delay circuit on the triode BG4 base stage in the described load fault protection circuit during with the triode conducting, this circuit is made up of resistance R 7 and capacitor C 5.Described coupling coil L5 goes here and there on the magnetic core of output transformer T1 and choking-winding L3 around forming.When load open circuit, the amplitude of the signal of coupling coil L5 output increases by 50% approximately, detects its inverse peak voltage by diode D6 voltage-stabiliser tube D11 is punctured, after described integrating circuit time-delay, direct current amplifier amplify, make electronic switch BG4 conducting, oscillating tube BG3 failure of oscillation; Simultaneously, the signal that coupling coil L5 is exported detects posivtive spike voltage through diode D12, D13, is respectively triode BG6, BG7 after capacitor C 11 and C8 filtering negative supply is provided.

Referring to Fig. 2, described pulse ablates device is by triode BG5 and be serially connected in electric capacity C6 resistance R 11 on its base stage, and the discharge diode D10 that is connected across on triode BG5 base stage and the emitter forms, the collector electrode of triode BG5 connects the base stage of oscillating tube BG3, grounded emitter, connect the negative pole of capacitor C 7 after base stage serial connection capacitor C 6 resistance R 11, the spike forward position in the excision feedback signal.

Referring to Fig. 2, first important additional technical feature of the present utility model is also to comprise start-up circuit, series circuit and the triode BG1 that this start-up circuit is made up of resistance R 1, voltage-stabiliser tube D5, resistance R 4, biasing resistor R2, the R3 and the storage capacitor C2 that are located on the triode BG1 base stage are formed, described series circuit is connected across the base stage of the positive pole and the oscillating tube BG3 of capacitor C 1 in the current rectifying and wave filtering circuit, the collector electrode connecting resistance R1 of triode BG1 and the tie point of voltage-stabiliser tube D5, grounded emitter, base stage connects the negative pole that negative peak detects diode D6 through upper offset resistance R 3.The effect of described start-up circuit has two; the one, when exporting first negative pulse, in time enabling signal is excised output transformer T1; the 2nd, guarantee when load open circuit, the load fault protection circuit with the feedback signal short circuit after, bikini oscillator can not start immediately.

Referring to Fig. 2, second additional technical feature of the present utility model is also to comprise current-limiting circuit, this circuit by be serially connected on the oscillating tube BG3 emitter sample resistance R6 and by triode BG2, the amplifying circuit that BG7 forms constitutes, the base stage of triode BG2 is through current-limiting resistance R6 ground connection, collector electrode is connected through the base stage of resistance R 8 with triode BG7, the collector electrode of triode BG7 is connected with the base stage of triode BG4 in the electronic switch through resistance R 9, the over-current signal that sample resistance R5 is exported amplifies the back through described amplifying circuit and controls triode BG4 in the electronic switch, the feedback signal short circuit that coupling coil L4 is exported.

Claims

1. novel electron ballast, comprise filter rectifier, transformer coupled feedback bikini oscillator, it is characterized in that also comprising load fault protection circuit and pulse ablates device, described load fault protection circuit is by the coupling coil (L5) of string on output transformer (T1) and the choke (L3), negative peak straightening diode (D6), the negative peak threshold voltage detects delay circuit (D11, R14, C10), three grades of dc amplification circuit (BG9, BG8, BG6) with electronic switch (BG4) be connected successively form, described negative peak threshold voltage detects delay circuit and is made of voltage stabilizing didoe (D11) resistance (R14) on first order amplifying triode (BG9) base stage that is serially connected in dc amplification circuit and the integrating capacitor (C10) on this transistor base of cross-over connection and the emitter, described electronic switch is made of triode (BG4), the collector and emitter of this triode is connected across on the base stage and emitter of the oscillating tube (BG3) in the described bikini oscillator, the feedback signal shorted to earth during with load faulty; Described pulse ablates device is by triode (BG5) and be serially connected in current-limiting resistance (R11) capacitance (C6) on this transistor base and the discharge diode (D10) that is connected across on triode (BG5) base stage and the emitter is formed, the base stage of described triode (BG5) links to each other with the input of described bikini oscillator with current-limiting resistance (R11) through capacitance (C6), the base stage of the oscillating tube (BG3) in collector electrode and the bikini oscillator links to each other, grounded emitter is with spike forward position excision in the feedback signal.

2. a kind of novel electron ballast according to claim 1, it is characterized in that also comprising start-up circuit, this circuit is by resistance (R1), voltage-stabiliser tube (D5), series circuit and triode (BG1) that resistance (R4) is formed, be located at the biasing resistor (R2 on triode (BG1) base stage, R3) and storage capacitor (C2) form, described series circuit is connected across the base stage of the positive pole and the oscillating tube (BG3) of electric capacity in the current rectifying and wave filtering circuit (O1), the collector electrode connecting resistance (R1) of triode (BG1) and the tie point of voltage-stabiliser tube (D5), grounded emitter, base stage connects the negative pole that negative peak detects diode (D6) through upper offset resistance (R3).

3. a kind of novel electron ballast according to claim 1 and 2, it is characterized in that also comprising current-limiting circuit, this circuit is by the amplifying circuit formation that is serially connected in the sample resistance (R5) on oscillating tube (BG3) emitter and is made up of triode (BG2), (BG7), the base stage of triode (BG2) is through biasing (R6) ground connection, collector electrode is connected through the base stage of resistance (R8) with triode (BG7), and the collector electrode of triode (BG7) is connected with the base stage of triode (BG4) in the electronic switch through resistance (R9).