CN201260265Y

CN201260265Y - Electronic ballast circuit for light modulation type fluorescent lamp

Info

Publication number: CN201260265Y
Application number: CNU2008201475900U
Authority: CN
Inventors: 陈永峰
Original assignee: Shenzhen Xinghaodi Electron Co Ltd
Current assignee: Shenzhen Xinghaodi Electron Co Ltd
Priority date: 2008-09-19
Filing date: 2008-09-19
Publication date: 2009-06-17
Anticipated expiration: 2018-09-19

Abstract

The utility model discloses an electronic ballast circuit of a light-adjusting type fluorescent lamp, which has good effect of stepless light adjusting within wide ranges. The electronic ballast circuit of the light-adjusting type fluorescent lamp can prolong the service life of a fluorescent lamp, thus leading the service life of the fluorescent lamp not to be over due to the blackening at early stage. The electronic ballast circuit comprises an EMC filtering circuit (1), a rectifying circuit (2), a DC filtering circuit (3), a high-frequency oscillating and half-bridge driving circuit (4), a resonating circuit (5), a feedback compensating circuit (6) and a light-adjusting signal circuit (7). The high-frequency oscillating and half-bridge driving circuit (4) comprises a light-adjusting control chip (U1), and a high-end driving switch tube (Q1) and a low-end driving switch tube (Q2) of the light-adjusting control chip (U1). The resonating circuit (5) comprises a resonant inductor (T1-1) and a resonant capacitor (C14). The feedback compensating circuit (6) comprises three feedback compensating capacitors (C2, C3 and C7). The electronic ballast circuit can be widely applied in the light-adjusting field of lamps.

Description

The Light modulating type circuit of fluorescent lamp electronic ballast

Technical field

The utility model relates to a kind of Light modulating type circuit of fluorescent lamp electronic ballast.

Background technology

The higher-order of oscillation that existing Light modulating type circuit of fluorescent lamp electronic ballast generally comprises EMC filter circuit, AC/DC rectification circuit, DC filter circuit, formed by an IC and post the half-bridge drive circuit that two MOS form, and dim signal circuit, resonant circuit, feedback compensation circuit.The light modulation principle is as follows: civil power carries out filtering and rectification through EMC filter circuit and rectification circuit, then through the higher-order of oscillation and half-bridge drive circuit to resonant circuit, for providing high-frequency ac, fluorescent lamp starts high pressure, when external dimmer for light control, the feedback compensation circuit can allow the late-class circuit operate as normal, in the level resonant circuit of back, get a high relatively alternating voltage and feed back to the prime input, the dim signal of dim signal circuit output changes reference voltage on the IC pin position through external dimmer, changing and the electric current of control by fluorescent lamp, thereby fluorescent lamp is carried out light modulation.But the stepless dimming effect of existing Light modulating type electronic ballast for fluoresent lamp is relatively poor, can not carry out light modulation in the scope of broad.

The utility model content

Technical problem to be solved in the utility model is to overcome the deficiencies in the prior art, the Light modulating type circuit of fluorescent lamp electronic ballast that a kind of stepless dimming is effective, can carry out light modulation in the scope of broad is provided, this Light modulating type circuit of fluorescent lamp electronic ballast can prolong the useful life of fluorescent lamp, is unlikely to die of old age because of early stage blackout.

The technical scheme that the utility model adopted is: the utility model comprises the EMC filter circuit, rectification circuit, the DC filter circuit, the higher-order of oscillation and half-bridge drive circuit, resonant circuit, the feedback compensation circuit, the dim signal circuit, the described higher-order of oscillation and half-bridge drive circuit comprise the brightness adjustment control chip, two driving switch metal-oxide-semiconductors, the grid of two described driving switch metal-oxide-semiconductors respectively with the height of described brightness adjustment control chip, low side is connected, the drain electrode of one of them described driving switch metal-oxide-semiconductor is connected with direct current voltage bus, source electrode links to each other with the drain electrode of another described driving switch metal-oxide-semiconductor, the source ground of another described driving switch metal-oxide-semiconductor, described resonant circuit comprises resonant inductance, resonant capacitance, described feedback compensation circuit comprises three feedback compensation electric capacity.

Also be provided with two secondary on the described resonant inductance, two described secondary are connected with the filament at fluorescent lamp two ends respectively.

Described rectification circuit is a full bridge rectifier.

Described brightness adjustment control chip model is L6574.

The beneficial effects of the utility model are: the utility model adopts the light modulation of external dimmer mode, the low more then frequency of power is high more when light modulation, simultaneously in the dimmer course of work, can give filament pre-heating, reach better dimming effect, also help prolonging the useful life of fluorescent lamp, can be widely used in various dissimilar dimmers, so the utility model good dimming effect, can carry out light modulation in the scope of broad, this Light modulating type circuit of fluorescent lamp electronic ballast can prolong the useful life of fluorescent lamp, is unlikely to die of old age because of early stage blackout.

Description of drawings

Fig. 1 is circuit theory diagrams of the present utility model;

Fig. 2 is a current trend schematic flow sheet of the present utility model;

Fig. 3 is the drive signal schematic diagram of two switching tubes of the present utility model.

Embodiment

As Fig. 1, Fig. 2, shown in Figure 3, the utility model comprises EMC filter circuit 1, rectification circuit 2, DC filter circuit 3, the higher-order of oscillation and half-bridge drive circuit 4, resonant circuit 5, feedback compensation circuit 6, dim signal circuit 7, fluorescent lamp 8, the described higher-order of oscillation and half-bridge drive circuit 4 comprise brightness adjustment control chip U1, two driving switch metal-oxide-semiconductor Q1, Q2, two described driving switch metal-oxide-semiconductor Q1, the grid of Q2 respectively with the height of described brightness adjustment control chip U1, low side HVG, LVG is connected, the drain electrode of one of them described driving switch metal-oxide-semiconductor Q1 is connected with direct current voltage bus, source electrode links to each other with the drain electrode of another described driving switch metal-oxide-semiconductor Q2, the source ground of another described driving switch metal-oxide-semiconductor Q2, described resonant circuit 5 comprises resonant inductance T1-1, resonant capacitance C14, also be provided with two secondary T1-2 on the described resonant inductance T1-1, T1-3, two described secondary T1-2, T1-3 is connected with the filament at described fluorescent lamp 8 two ends respectively, inductive transformer T1-1 in the described resonant circuit 5 provides high pressure when being used to described fluorescent lamp 8 resonance, two described secondary T1-2 and T1-3 are the filament pre-heating of described fluorescent lamp 8, can reach better dimming effect, described feedback compensation circuit 6 comprises three feedback compensation capacitor C 2, C3, C7, described rectification circuit 2 is a full bridge rectifier, and described brightness adjustment control chip U1 model is L6574.

Civil power carries out filtering and rectification through described EMC filter circuit 1 and described rectification circuit 2, then through the described higher-order of oscillation and half-bridge drive circuit 4 to described resonant circuit 5, for providing high-frequency ac, fluorescent lamp starts high pressure, when external dimmer for light control, described feedback compensation circuit 6 can allow the late-class circuit operate as normal, in the level resonant circuit of back, get a high relatively alternating voltage and feed back to the prime input, the dim signal of described dim signal circuit 7 outputs changes reference voltage on the described brightness adjustment control chip U1 pin position through external dimmer, pass through the electric current of described fluorescent lamp 8 with change and control, thereby described fluorescent lamp 8 is carried out light modulation.

Operation principle of the present utility model is as follows: with described brightness adjustment control chip U1 and two described driving switch metal-oxide-semiconductor Q1, the described higher-order of oscillation that peripheral circuits such as Q2 are formed and half-bridge drive circuit 4 produce drive signal, its drive signal as shown in Figure 3, two described driving switch metal-oxide-semiconductor Q1, the work of Q2 symmetry, for avoiding two pipe conductings simultaneously, the IC interior logic of described brightness adjustment control chip U1 can guarantee that high-side driver HVG and low side drive the Dead Time that LVG has a minimum, when a described driving switch metal-oxide-semiconductor Q1 conducting, electric current flows through switching tube Q1, capacitor C 13, C14, T1-1, T1-2, the fluorescent tube of T1-3 and described fluorescent lamp 8, when another described driving switch metal-oxide-semiconductor Q2 conducting, electric current is crossed switching tube Q2, capacitor C 13, C14, T1-1, T1-2, the fluorescent tube of T1-3 and described fluorescent lamp 8, the variation of the 4th pin RING voltage by described brightness adjustment control chip U1, can play corrective action to the frequency of IC interior voltage controlled oscillator, because the variation of frequency, electric current by described fluorescent lamp 8 changes, therefore can reach the purpose of light modulation, by regulating the circumscribed dimmer, make the DC voltage change of the 7th pin OPIN+ that is input to described brightness adjustment control chip U1, thereby reach the purpose of light modulation.

The utility model relies on the electronics integrated technology, adopting special-purpose brightness adjustment control chip L6574 is core, reasonable configuration peripheral driver signal and handle the output drive signal and reach the purpose of light modulation, adjustable range is 10～100%, that research and development is middle power 24W at present.The utility model comprises three modules: 1, Power Entry Module; 2, light modulation pumping signal input module; 3, be used to light the output signal processing module of fluorescent lamp.Power supply is by in the input brightness adjustment control chip after the straight filtering of alternation, handle by the brightness adjustment control chip analysis, the output dimming control signal, feed back in the brightness adjustment control chip after the peripheral modulation, again by brightness adjustment control chip output drive electric current, control 2 VMOS power field effect transistors, by the LC resonant circuit of 2 VMOS power field effect transistors driving back, to reach the effect of lighting fluorescent tube.

The utility model can be widely used in light fixture light modulation field.

Claims

1, a kind of Light modulating type circuit of fluorescent lamp electronic ballast, comprise EMC filter circuit (1), rectification circuit (2), DC filter circuit (3), the higher-order of oscillation and half-bridge drive circuit (4), resonant circuit (5), feedback compensation circuit (6), dim signal circuit (7), it is characterized in that: the described higher-order of oscillation and half-bridge drive circuit (4) comprise brightness adjustment control chip (U1), two driving switch metal-oxide-semiconductor (Q1, Q2), two described driving switch metal-oxide-semiconductor (Q1, Q2) grid respectively with the height of described brightness adjustment control chip (U1), low side (HVG, LVG) be connected, the drain electrode of one of them described driving switch metal-oxide-semiconductor (Q1) is connected with direct current voltage bus, source electrode links to each other with the drain electrode of another described driving switch metal-oxide-semiconductor (Q2), the source ground of another described driving switch metal-oxide-semiconductor (Q2), described resonant circuit (5) comprises resonant inductance (T1-1), resonant capacitance (C14), described feedback compensation circuit (6) comprise three feedback compensation electric capacity (C2, C3, C7).

2, Light modulating type circuit of fluorescent lamp electronic ballast according to claim 1, it is characterized in that: also be provided with two secondary (T1-2, T1-3) on the described resonant inductance (T1-1), two described secondary (T1-2, T1-3) filament with the fluorescent lamp two ends respectively are connected.

3, Light modulating type circuit of fluorescent lamp electronic ballast according to claim 1 is characterized in that: described rectification circuit (2) is a full bridge rectifier.

4, Light modulating type circuit of fluorescent lamp electronic ballast according to claim 1 is characterized in that: described brightness adjustment control chip (U1) model is L6574.