CN101877929A

CN101877929A - Isolation-type low-power high-strength digital ballast for gas discharge lamp

Info

Publication number: CN101877929A
Application number: CN201010222825XA
Authority: CN
Inventors: 王念春
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2010-07-08
Filing date: 2010-07-08
Publication date: 2010-11-03

Abstract

The invention discloses an isolation-type low-power high-strength digital ballast for a gas discharge lamp. The ballast mainly comprises an input filtering circuit, an unrectifiable circuit, an APFC step-up and power factor correction circuit, a BUCK step-down circuit, a full bridge inverter circuit, a high-voltage ignition circuit, a power supply circuit and a digital control and protection circuit. The BUCK circuit adopts an inverse manner and divides the earth potential of the entire circuit into two parts and isolates corresponding power supply parts, so as to effectively prevent the high-voltage ignition circuit from interfering with a pre-stage circuit and effectively isolate the device damage range in the case of failure. The digital control and protection circuit uses a single chip with an AD and program storage unit in the chip and can effectively detect the BUCK output voltage of the ballast and the environment temperature as well as output the PWM control signal of full bridge inversion. The ballast has the advantages of small volume, light weight, high input power factor, high efficiency, comprehensive protection functions, capability of effectively limiting the failure damage range, and the like.

Description

A kind of isolated low-power high-strength digital ballast for gas discharge lamp

Technical field

The present invention relates to a kind of isolated low-power high-strength digital ballast for gas discharge lamp, it provides a positive voltage-current characteristic when high-intensity gas discharge lamp is worked, play the ballast effect, high-intensity gas discharge lamp with negative resistance charactertistic can stably be operated on the working point of a certain design, belong to the technical field that the illumination electronic product is made.

Background technology

" green illumination ", be the new ideas that occur the nineties in 20th century, be meant illumination Design by science, adopt electric lighting product (electric light source, lamp electrical appliance annex, light fixture, the distribution equipment of efficient height, life-span length, safety and stable performance, and light controller and light shutter device), improve the condition and the quality of people work, study, life, thereby create efficient, comfortable a, safety, economy, useful environment and demonstrate fully the illumination of modern civilization.

High-intensity gas discharge lamp is a third generation electric light source, has the light efficiency height, and the life-span is long, and color rendering is good, and characteristics such as obvious energy conservation are obtaining to use widely, is desirable " green illumination " light source.But high-intensity gas discharge lamp has negative resistance charactertistic, and must be equipped with the ballast with positive resistance characteristic during use could steady operation.The traditional inductance type ballast of the most uses of existing high-intensity gas discharge lamp, not only volume is big, Heavy Weight, and consume more non-ferrous metal, and whole efficiency is low, and control characteristic is poor, can not start fast.

The electric ballast of high-intensity gas discharge lamp has overcome the shortcoming of traditional inductance type ballast preferably, but (3～5kV) devices to ballast have certain harm to the high voltage of electric ballast work initial stage output, also can influence the operate as normal of controller, in addition under various unpredictalbe states, ballast also might break down, existing ballast can cause device large tracts of land even all damages in the ballast under failure condition, the present invention is by the improvement to the ballast structure, use the earth potential and the power supply of isolating, solve above-mentioned several problem preferably.

Summary of the invention

Technical problem: the objective of the invention is to overcome some weak point in the existing electronic ballast of high intensity gas discharge lamp technology, provide a kind of defencive function complete, more stable work can effectively prevent town under the failure condition

A kind of isolated low-power high-strength digital ballast for gas discharge lamp that the device large tracts of land is damaged in the stream device.

Technical scheme: for realizing this purpose, the present invention solves by following technical proposals:

Isolated low-power high-strength digital ballast for gas discharge lamp of the present invention; it is characterized in that in this ballast; EMI filter circuit, uncontrollable rectification circuit, APFC booster circuit, BUCK reduction voltage circuit, full bridge inverter, high-tension ignition circuit, high-intensity gas discharge lamp are connected in series in proper order; power-supplying circuit is powered to each several part, and control connects BUCK reduction voltage circuit, full bridge inverter respectively with protective circuit.

The BUCK reduction voltage circuit adopts a kind of DC converting of falling BUCK structure, the positive electrode of BUCK reduction voltage circuit connects the positive electrode output and the full bridge inverter positive electrode input of APFC booster circuit respectively, the negative electrode output of the negative electrode input termination APFC booster circuit of BUCK reduction voltage circuit, the resistance that this end is connected in series by order, driving transistors, inductor connects full bridge inverter negative electrode input, the positive electrode of BUCK reduction voltage circuit and driving transistors, tie point between the inductor oppositely connects a diode, connects a capacitor between the both positive and negative polarity of BUCK reduction voltage circuit output.

The output of BUCK reduction voltage circuit is turn-offed in control and the output of protective circuit by a switching value signal controlling BUCK reduction voltage circuit of optocoupler output under failure condition, shield.

Control and control chip in the protective circuit use the single-chip microcomputer that has 8 or 10 AD and memory under program function in the sheet; detect the output voltage of BUCK reduction voltage circuit by resitstance voltage divider; use the thermistor testing environment temperature of secondary temperature coefficient, use that the hardware PWM port of single-chip microcomputer or common IO port output two-way complementary duty cycle is 50%, frequency adjustable is the pwm signal control full-bridge inverting chip of 10Hz～400Hz.

Beneficial effect; The invention has the advantages that: the supply power mode that adopts two-stage to isolate to the interference of control chip, may be limited to the device failure scope of ballast under the failure condition again in the time of both can reducing the Metal halogen lamp ignition trigger; Digital control chip is to voltage, temperature, and electric currents etc. detect in real time, can turn-off the output of BUCK circuit under failure condition, and defencive function is perfect.Can effectively improve the intelligent protection function and the reliability of ballast.

Description of drawings

Fig. 1 is a system of the present invention catenation principle block diagram.

Fig. 2 is a BUCK reduction voltage circuit schematic diagram of the present invention.

Fig. 3 is power circuit principle figure of the present invention.

Embodiment

Below in conjunction with accompanying drawing and embodiment technical scheme of the present invention is described in further detail.

The present invention is that a kind of isolated low-power high-strength digital ballast for gas discharge lamp is by input filter circuit 1, can not rectification circuit 2, APFC boosts and circuit of power factor correction 3, BUCK reduction voltage circuit 4, full bridge inverter 5, high-tension ignition circuit 6, power-supplying circuit 7, digital control and protective circuit 8 is formed; The positive electrode of BUCK reduction voltage circuit 4 connects the positive electrode output and the full bridge inverter 5 positive electrode inputs of APFC booster circuit 3 respectively, the negative electrode output of the negative electrode input termination APFC booster circuit 3 of BUCK reduction voltage circuit 4, this end connects full bridge inverter 5 negative electrode inputs by resistance R, driving transistors G, the inductor L that order is connected in series, the positive electrode of BUCK reduction voltage circuit 4 oppositely is connected a diode D with tie point between driving transistors G, the inductor L, connects a capacitor C between the both positive and negative polarity of BUCK reduction voltage circuit 4 outputs.

BUCK reduction voltage circuit 4 wherein adopts a kind of inverted structure, earth potential in the digital ballast of the present invention is divided into two parts, APFC booster circuit 3 and BUCK reduction voltage circuit 4 shared one group of power supply can be simplified the structure of BUCK drive circuit, save optocoupler or isolating transformer; The full bridge inverter 5 of digital ballast and control and protective circuit 8 shared another group power supplys can be measured the BUCK output voltage by simple resitstance voltage divider like this, and directly output pwm signal drives full bridge inverter;

For saving cost, the power supply in the digital ballast of the present invention adopts the inductance secondary power supply in the APFC booster circuit 3.This inductance has two or three independent isolating secondary, and one is detected ZCS for the control chip of booster circuit and uses, in addition two through behind voltage stabilizing circuits or the voltage-stabiliser tube for two differently chip uses in the current potential structure in the digital ballast of the present invention.Because power supply is isolated mutually, can effectively prevent the large-area damage of device in the digital ballast of the present invention under failure condition;

Control in the digital ballast of the present invention and protective circuit 8 master control chips are selected the single-chip microcomputer that has 8 or 10 AD and program storaging chip in the sheet for use, detect the output voltage of BUCK circuit by resitstance voltage divider, judge the digital ballast success of whether lighting a fire by the size that detects voltage, whether external light fixture opens a way, whether ambient temperature meets digital ballast operate as normal requirement etc., accurate timing is provided simultaneously, realizes protection the multiple function of digital ballast;

Single-chip microcomputer is 50% by hardware PWM port or common IO port output two-way complementary duty cycle in control in the digital ballast of the present invention and the protective circuit 8, frequency adjustable (the pwm signal control full-bridge inverting chip of 10Hz～400Hz).Detecting under the abnormal conditions, single-chip microcomputer cuts out the BUCK output voltage by the output of a switching value signal controlling BUCK reduction voltage circuit 4 of optocoupler output.

Embodiment: as shown in Figure 1; isolated low-power high-strength digital ballast for gas discharge lamp; comprise EMI filter circuit 1; uncontrollable rectification circuit 2, APFC booster circuit 3, BUCK reduction voltage circuit 4; full bridge inverter 5; high-tension ignition circuit 6, power-supplying circuit 7, digital control and protective circuit 8.APFC booster circuit 3 is raised to uncontrollable rectification circuit 2 VD about 400V during work, the power factor of circuit is reached more than 0.95, BUCK reduction voltage circuit 4 drops to the designation number value with 400V voltage, high-tension ignition circuit 6 provides the starting resistor of 3～5kV, high intensity gas discharge lamp is started working, full bridge inverter 5 is according to the different operating period of light fixture, and the ac square-wave voltage of output 10～400Hz prevents " acoustic resonance " phenomenon.Control detects BUCK output voltage and ambient temperature with protective circuit 8, judges the operating state of light fixture, and various protections are provided.

Fig. 2 is a BUCK reduction voltage circuit of the present invention, has adopted a kind of inverted structure, has simplified the drive circuit of BUCK switching tube, has saved optocoupler or driving transformer, has improved the reliability that drives.Earth potential with digital ballast is divided into two parts simultaneously, high-tension interference in the time of can effectively preventing to light a fire, simultaneously damage scope that can limiting device under failure condition.

Fig. 3 is a power circuit of the present invention; in this embodiment; APFC inductance secondary has two windings; APFC booster circuit 3, secondary of BUCK reduction voltage circuit 4 partial commons among ZCS testing circuit in the APFC circuit and Fig. 1, full bridge inverter 5, digital control and protective circuit 8 parts are with another secondary power supply.

Claims

1. isolated low-power high-strength digital ballast for gas discharge lamp; it is characterized in that in this ballast; EMI filter circuit (1), uncontrollable rectification circuit (2), APFC booster circuit (3), BUCK reduction voltage circuit (4), full bridge inverter (5), high-tension ignition circuit (6), high-intensity gas discharge lamp are connected in series in proper order; power-supplying circuit (7) is to the each several part power supply, and control connects BUCK reduction voltage circuit (4), full bridge inverter (5) respectively with protective circuit (8).

2. a kind of isolated low-power high-strength digital ballast for gas discharge lamp according to claim 1, it is characterized in that BUCK reduction voltage circuit (4) adopts a kind of DC converting of falling BUCK structure, the positive electrode of BUCK reduction voltage circuit (4) connects the positive electrode output and full bridge inverter (5) the positive electrode input of APFC booster circuit (3) respectively, the negative electrode output of the negative electrode input termination APFC booster circuit (3) of BUCK reduction voltage circuit (4), the resistance (R) that this end is connected in series by order, driving transistors (G), inductor (L) connects full bridge inverter (5) negative electrode input, the positive electrode of BUCK reduction voltage circuit (4) and driving transistors (G), tie point between the inductor (L) oppositely connects a diode (D), connects a capacitor (C) between the both positive and negative polarity of BUCK reduction voltage circuit (4) output.

3. a kind of isolated low-power high-strength digital ballast for gas discharge lamp according to claim 1; it is characterized in that control and the output of protective circuit (8) by an optocoupler switching value signal controlling BUCK reduction voltage circuit of output (4); under failure condition, turn-off BUCK reduction voltage circuit (4) output, shield.

4. a kind of isolated low-power high-strength digital ballast for gas discharge lamp according to claim 1; it is characterized in that control and control chip in the protective circuit (8) use the single-chip microcomputer that has 8 or 10 AD and memory under program function in the sheet; detect the output voltage of BUCK reduction voltage circuit (4) by resitstance voltage divider; use the thermistor testing environment temperature of secondary temperature coefficient, use that the hardware PWM port of single-chip microcomputer or common IO port output two-way complementary duty cycle is 50%, frequency adjustable is the pwm signal control full-bridge inverting chip of 10Hz～400Hz.