CN203387755U

CN203387755U - Electronic ballast

Info

Publication number: CN203387755U
Application number: CN201320474114.0U
Authority: CN
Inventors: 权循华; 杜庆朋; 谢洋; 陈辉
Original assignee: HEFEI DAMING ENERGY-SAVING TECHNOLOGY CO LTD
Current assignee: Hefei Daming Zhilian Technology Co ltd
Priority date: 2013-08-05
Filing date: 2013-08-05
Publication date: 2014-01-08
Anticipated expiration: 2023-08-05

Abstract

The utility model relates to the technical field of a ballast, and especially relates to an electronic ballast. The electronic ballast comprises a half-bridge driving module and a half-bridge inverter circuit. The half-bridge driving module outputs a driving signal to the half-bridge inverter circuit to control the half-bridge inverter circuit to start/stop. An output inductor L and a starting capacitor C1 are sequentially connected in series between the output pins 1, 2 of the half-bridge inverter circuit. An HID lamp is connected in parallel at the two ends of the starting capacitor C1. The electronic ballast further comprises a voltage detection processing module. A capacitor C2 and a capacitor C3 are connected in series and then are connected in parallel at the two ends of the starting capacitor C1. The voltage detection processing module collects a voltage at the two ends of the capacitor C2 and outputs a control signal to the half-bridge driving module after the voltage is processed. Voltages at the two ends of the lamp tube when the HID lamp is in started state and unstarted state differ greatly, so that after the voltage is divided through the capacitor C2 and the capacitor C3, the voltage detection module detects a voltage at the two ends of the capacitor C3 and judgment of whether the HID lamp is successfully started or not through the value of the voltage is very reliable.

Description

Electric ballast

Technical field

The utility model relates to the ballast technical field, particularly a kind of electric ballast.

Background technology

The HID lamp is exactly the english abbreviation of high-voltage gas discharging light, is the general designation of mercury lamp, sodium vapor lamp, Metal halogen lamp, xenon lamp, and " volt-ampere " performance of its electric discharge is negative resistance charactertistic, therefore in the operating circuit of lamp, needs to connect current limiting device, i.e. usually said ballast.Ballast has again dividing of Inductive ballast and electric ballast, because inductance type ballast is operated in the power frequency mains frequency, volume is large, heavy, also need to consume the metal materials such as a large amount of copper and silicon steel, heat radiation difficulty, inefficiency, lamp be luminous the more shortcoming such as stroboscopic, and it is substituted by electric ballast gradually.

As shown in Figure 1, electric ballast is when starting, half-bridge driven module 1 output drive signal is to half-bridge inversion circuit 2, half-bridge inversion circuit 2 output high-frequency ac voltages are added on the LC series resonant circuit be connected with lamp, because the natural frequency of LC series resonant circuit is consistent with the driving frequency of half-bridge driven module 1 output, it is minimum that the now impedance of LC series resonant circuit reaches, it is maximum that electric current reaches, at the two ends of start-up capacitance C and outputting inductance L, can produce the amplitude equal direction contrary up to 3～5KV high pressure, the high pressure at start-up capacitance C two ends is added in the HID lamp tube ends and lights HID lamp 3 for the inert gas punctured in the HID wick.When HID lamp 3 starts successfully, the impedance operator of HID lamp 3 changes, and the voltage at its two ends is far smaller than the high pressure while starting, and ballast starts normal operation, outputting inductance L plays Limited Current and increases, and guarantees that fluorescent tube obtains normal operation required modulating voltage and lamp current; When HID lamp 3 damages or HID lamp tube ends high pressure while being not enough to start the HID fluorescent tube, HID lamp 3 starts unsuccessfully, if now do not close half-bridge inversion circuit 2, high pressure can continue to be added in the two ends of outputting inductance L and start-up capacitance C, it is damaged, finally cause the damage of this electric ballast.

The generation damaged for the electric ballast of avoiding HID lamp 3 to start unsuccessfully causing, existing way is that the power output by detecting half-bridge inversion circuit 2 judges whether HID lamp 3 starts successfully, the power output that half-bridge inversion circuit 2 detected when power detection module 4 hour, judge that HID lamp 3 starts unsuccessfully, outputs signal to half-bridge driven module 1 and makes it stop output drive signal.This scheme exists following not enough: in actual applications; when HID lamp 3 starts unsuccessfully, outputting inductance L and start-up capacitance C also can produce power consumption; when this power consumption is greater than the criterion of power detection module 4, can make it produce erroneous judgement, the reliability of protection is inadequate.

The utility model content

Whether the purpose of this utility model is to provide a kind of electric ballast, can detect reliably the HID lamp and successfully start.

For realizing above purpose, the technical solution adopted in the utility model is: a kind of electric ballast, comprise the half-bridge driven module, half-bridge inversion circuit, described half-bridge driven module output drive signal to half-bridge inversion circuit is controlled its start/stop, the output pin 1 of described half-bridge inversion circuit, 2 are in series with outputting inductance L successively, start-up capacitance C1, the HID lamp is connected in parallel on the two ends of start-up capacitance C1, also comprise the voltage detecting processing module, described capacitor C 2 and the two ends that are connected in parallel on start-up capacitance C1 after capacitor C 3 is connected, the voltage detecting processing module gather the voltage at capacitor C 2 two ends and processed after output control signals to the half-bridge driven module.

Compared with prior art, there is following technique effect in the utility model: the HID lamp is connected in parallel on lamp tube ends, lamp tube ends voltage is exactly the voltage at start-up capacitance C1 two ends, because the HID lamp starts and the voltage phase difference of starting state lamp tube ends is very not large, therefore by capacitor C 2, C3 by after this voltage dividing potential drop, the voltage at voltage detection module Detection capacitance C3 two ends, and logical superpotential size judges that whether the HID lamp successfully starts is very reliable.

The accompanying drawing explanation

Fig. 1 is the prior art schematic diagram;

Fig. 2 is the utility model schematic diagram.

Embodiment

Below in conjunction with Fig. 2, the utility model is done and is described in further detail.

Traditional startup failure protective circuit judges by detecting the half-bridge inversion circuit power output whether the HID lamp starts successfully; when the HID lamp starts unsuccessfully, average power consumption is in 10～20W left and right; start successful mean consumption power in the 100W left and right; generally test point is arranged on to 50～60W so adopt power to judge when being detected, when being less than this, being judged to be and starting unsuccessfully.The power and the test point difference that while starting unsuccessfully due to the HID lamp, consume are less, and the power consumption occasional that when the HID lamp starts unsuccessfully, outputting inductance L and start-up capacitance C produce makes the power detected be greater than decision-point, so just reliable not.Comparatively speaking, when the HID lamp starts successfully, its both end voltage generally only has tens V; Start or while starting unsuccessfully, the voltage at its two ends is up to 3KV, under this two states, the voltage difference is very large, and does not have other factors to impact voltage.Therefore judge that by the voltage that detects HID lamp two ends whether the HID lamp starts is successfully very reliable in the utility model.

Consult Fig. 2, concrete scheme of the present utility model is: a kind of electric ballast, comprise half-bridge driven module 10, half-bridge inversion circuit 20, described half-bridge driven module 10 output drive signals to half-bridge inversion circuit 20 is controlled its start/stop, the output pin 1 of described half-

bridge inversion circuit

20, 2 are in series with outputting inductance L successively, start-up capacitance C1, HID lamp 40 is connected in parallel on the two ends of start-up capacitance C1, also comprise voltage detecting processing module 30, described capacitor C 2 and the two ends that are connected in parallel on start-up capacitance C1 after capacitor C 3 is connected, voltage detecting processing module 30 gather the voltage at capacitor C 2 two ends and processed after output control signals to half-bridge driven module 10.Due to half-bridge inversion circuit 20 output be high-frequency ac voltage, so voltage detecting processing module 30 can not directly be sampled to HID lamp tube ends voltage, but carry out after dividing potential drop the voltage to capacitor C 3 again by capacitor C 2, C3, samples processing.

Further; in order to reduce capacitor C 2, C3 exerts an influence to LC series resonant circuit frequency; the capacitance of described start-up capacitance C1 is greater than the capacitance of capacitor C 3; simultaneously because HID lamp tube ends voltage is very high when starting; in order to protect voltage detecting processing module 30; the capacitance of capacitor C 3 is greater than the capacitance of capacitor C 2, and wherein capacitor C 2 should be selected very little, the withstand voltage very high electric capacity of capacity, meets circuit requirement.

Startup principle owing to more mentioning the HID lamp in background technology, do not repeat them here.Below with regard to the operation principle of voltage detecting processing module 30, carefully state: no matter be that the HID fluorescent tube damages, when still HID lamp tube ends undertension is with startup, the high pressure that is added in the HID lamp tube ends all exists, by capacitor C 2, the dividing potential drop of C3 is detected by voltage detecting processing module 30, voltage detecting processing module 30 compares the voltage detected and the magnitude of voltage arranged in it, illustrate that higher than this value the HID lamp starts unsuccessfully, just send control signal and go to close half-bridge driven module 10, thereby close half-bridge inversion circuit 20, the protection electric ballast is not damaged by high pressure, after the HID lamp starts successfully, the voltage of HID lamp tube ends is far smaller than the high pressure while starting, this voltage is detected by voltage detecting processing module 30 after capacitor C 2, C3 dividing potential drop, because this magnitude of voltage is less than built-in decision-point, not export control signal to half-bridge driven module 10, half-bridge driven module 10 continues to drive half-bridge inversion circuit 20 work, continues to light the HID lamp.

Claims

1. an electric ballast, comprise half-bridge driven module (10), half-bridge inversion circuit (20), described half-bridge driven module (10) output drive signal to half-bridge inversion circuit (20) is controlled its start/stop, the output pin 1 of described half-bridge inversion circuit (20), 2 are in series with outputting inductance L successively, start-up capacitance C1, HID lamp (40) is connected in parallel on the two ends of start-up capacitance C1, it is characterized in that: also comprise voltage detecting processing module (30), described capacitor C 2 and the two ends that are connected in parallel on start-up capacitance C1 after capacitor C 3 is connected, voltage detecting processing module (30) gather the voltage at capacitor C 2 two ends and processed after output control signals to half-bridge driven module (10).

2. electric ballast as claimed in claim 1, it is characterized in that: the capacitance of described start-up capacitance C1 is greater than the capacitance of capacitor C 3, and the capacitance of capacitor C 3 is greater than the capacitance of capacitor C 2.