CN1787710B

CN1787710B - Starting controlling circuit for inductive type fluorescent lamp

Info

Publication number: CN1787710B
Application number: CN 200410089212
Authority: CN
Inventors: 王小明; 孟豪; 许伟义
Original assignee: Shanghai Beiling Co Ltd
Current assignee: Shanghai Beiling Co Ltd
Priority date: 2004-12-08
Filing date: 2004-12-08
Publication date: 2010-10-27
Anticipated expiration: 2024-12-08
Also published as: CN1787710A

Abstract

A start up control circuit of an inductance fluorescence lamp includes a commutation circuit, a clock generation and lamp-state sample circuit, a RC filter circuit and a control IC, in which, the commutation circuit includes MOSFET for converting AC/DC, a clock generation and lamp state sampling circuit sends the clock signals to the control IC to generate a standard time base pulse and sends the state voltage of the lamp to the control IC after subdivision to judge if the lamp is lighten or not, the RC filtering circuit sends the output voltage of the commutation circuit to the IC after limiting the current and filtering it to provide IC supply and the control IC is used in the warm-up control and on/off control of MOSFFT, which controls the warm-up time of a fuse, the inductance current of a ballast is the largest in ignition and the inductor generates very high inductance electromotive force to light the lamp at the moment of cutting off the current.

Description

A kind of start-up control circuit of inductive type fluorescent lamp

Technical field

The present invention relates to a kind of start-up control circuit of inductive type fluorescent lamp.

Background technology

As shown in Figure 1, normally make starter S with sheet metal by the fluorescent lamp that Inductive ballast constitutes, this class starter is to belong to mechanical in essence.Obtained using widely owing to it is cheap.But there is following shortcoming in such starter:

1. the bad control warm-up time of fluorescent wire, thereby filament pre-heating is insufficient, thus shortened the useful life of fluorescent tube.

2. be at random " the igniting opportunity " owing to starter S, be in inductance L big electric current moment igniting and few, this has caused the ignition voltage deficiency of fluorescent tube to be difficult to reach at every turn can both be with tube starting, so will dodge the fluorescent tube that just can ignite several times sometimes with the fluorescent lamp of this starter.

3. because this starter S makes of bimetal leaf, bimetal leaf is easy to generate fatigue and mechanical damage, so the useful life of this starter is not long yet.

At the shortcoming of sheet metal starter, the insider has proposed following improving one's methods.

As shown in Figures 2 and 3, as starting component, its principle is when AC imports with a controllable silicon, allows controllable silicon T conducting as current switch earlier, allows controllable silicon turn-off after conducting a period of time again, so also can realize the starter of lamp.But the deadly defect of this method is: general controllable silicon is that " zero current " turn-offs, so when controllable silicon turn-offed, the current i that flows through inductance L was almost nil, the induced electromotive force that inductance L produces is very little, not be enough to make tube starting, the probability lighted of fluorescent tube is very low in other words.

Summary of the invention

The object of the present invention is to provide a kind of start-up control circuit that can make the reliable inductive type fluorescent lamp that starts of fluorescent lamp.

The start-up control circuit of a kind of inductive type fluorescent lamp provided by the present invention, it is characterized in that, it comprises rectification circuit, clock generating and lamp state sample circuit, rc filter circuit and the control integrated circuit that is connected the fluorescent tube two ends, wherein: described rc filter circuit links to each other with control integrated circuit respectively with rectification circuit, described clock generating links to each other with rectification circuit, rc filter circuit and control integrated circuit respectively with lamp state sample circuit, again: rectification circuit, comprise MOSFET, as the AC/DC conversion; Clock generating and lamp state sample circuit, clock signal is delivered to control integrated circuit, make it the time main pulse of the standard that produces, simultaneously, the of-state voltage of fluorescent lamp is delivered to control integrated circuit after by dividing potential drop, judge that thus lamp " is lighted " and " not lighting " two states; Rc filter circuit is delivered to integrated circuit with the output voltage of described rectification circuit after through current limliting and filtering, so that the power supply of integrated circuit to be provided; Control integrated circuit is as the control of the control of warm-up time and MOSFFT " opening " and " pass ", and this control integrated circuit is caught the peak value of the inductive current of this inductive type fluorescent lamp, and when this inductive current reaches maximum shutoff MOSFET.

The start-up control circuit of above-mentioned inductive type fluorescent lamp, wherein, clock generating and lamp state sample circuit are made up of two resistance.

The start-up control circuit of above-mentioned inductive type fluorescent lamp, wherein, rc filter circuit is made up of resistance and capacitance-resistance filter.

Owing to adopted above-mentioned technical solution, make the warm-up time of Filament of fluorescent lamp controlled, thereby filament has obtained preheating effectively fully; The ballast inductor electric current is a maximum during igniting, turn-offs in a flash at electric current like this, and inductance L produces very high induced electromotive force, and this high-octane electromotive force is enough to make fluorescent tube to ignite.Therefore, the present invention can make fluorescent lamp reliably start.

Description of drawings

Fig. 1 is the schematic diagram of existing a kind of fluorescent lamp that is made of Inductive ballast;

Fig. 2, Fig. 3 are the schematic diagrames of existing other two kinds of fluorescent lamps that are made of Inductive ballast;

Fig. 4 is the schematic diagram of the start-up control circuit of inductive type fluorescent lamp of the present invention;

Fig. 5 is the voltage oscillogram that A is ordered in the circuit of the present invention;

Fig. 6 is the waveform corresponding relation view of current i and A point voltage in the circuit of the present invention.

Embodiment

As shown in Figure 4, the present invention, it is a kind of start-up control circuit of inductive type fluorescent lamp, it comprises rectification circuit 1, clock generating and lamp state sample circuit 2, rc filter circuit 3 and the control integrated circuit 4 that is connected the fluorescent tube two ends, wherein: rc filter circuit 3 links to each other with control integrated circuit 4 respectively with rectification circuit 1, and clock generating links to each other with rectification circuit 1, rc filter circuit 3 and control integrated circuit 4 respectively with lamp state sample circuit 2.

Rectification circuit 1 is as the AC/DC conversion, and it is made up of electric bridge BR, MOSFET (mos field effect transistor) and resistance R 4, and wherein MOSFET is a current switch.

Clock generating and lamp state sample circuit 2 are made up of two resistance R 2, R3, and the clock signal of 100Hz is delivered to integrated circuit SD end by the A point by R2, make integrated circuit obtain the time main pulse of a standard; Also deliver to the SD end of integrated circuit after the bleeder circuit dividing potential drop that the of-state voltage of lamp is made up of R2 and R3, can judge that thus lamp " is lighted " and two states of " not lighting ".

Rc filter circuit 3 is made up of resistance R 1 and capacitance-resistance filter C, delivers to the VCC end of integrated circuit after voltage process current limliting that A is ordered and the filtering, so that the power supply of integrated circuit to be provided.

Control integrated circuit 4 has played the control of the control of warm-up time and MOSFFT " opening " and " pass ", and the model that can adopt Shanghai Belling Co., Ltd. to produce is the chip of BL8303.

Its operation principle is described in detail in detail below:

When AC input beginning, when the out end of integrated circuit was output as high-impedance state, MOSFET was a conducting state, and preheat curent I is through inductance L → filament → rectifier bridge → MOSFET, and filament heats.

As shown in Figure 5, A point voltage oscillogram:

The voltage that A is ordered approximates about the threshold voltage 4V of MOSFET.The A point voltage passes through the current limliting of R1C and the filtering power supply as integrated circuit on the one hand; Be input to SD end time-base signal and phase signal as internal control circuit after the IC interior shaping through R2 on the other hand.If be set at 1 second warm-up time, the 10ms one-period the time main pulse as the frequency division input pulse, when rolling counters forward after 1 second just from low level of out end output of integrated circuit, thereby MOSFET is turn-offed.

Moreover in order to make ignition voltage high as much as possible, the time-delay of frequency divider is not only depended in the output of out, also will catch the peak value of preheat curent.When at preheat mode, the current i that flows through inductance equals to flow through the current i of MOSFET.As shown in Figure 6, the waveform corresponding relation of current i and A point voltage is:

Preheat curent maximum i _PeakJust in time be the mid point of the time-base signal of 10ms in the cycle, this point of 5ms just.If can be at the maximum i of preheat curent _PeakThis point is turn-offed MOSFET suddenly will produce maximum induced electromotive force in inductance, produce very sufficient high-pressure energy in lamp tube ends, is enough to make fluorescent tube to ignite.

More than all embodiment only for the explanation the present invention usefulness, but not limitation of the present invention, person skilled in the relevant technique, under the situation that does not break away from the spirit and scope of the present invention, can also make various conversion or modification, therefore all technical schemes that are equal to also should belong within the category of the present invention, should be limited by each claim.

Claims

1. the start-up control circuit of an inductive type fluorescent lamp, it is characterized in that, it comprises rectification circuit, clock generating and lamp state sample circuit, rc filter circuit and the control integrated circuit that is connected the fluorescent tube two ends, wherein: described rc filter circuit links to each other with control integrated circuit respectively with rectification circuit, described clock generating links to each other with rectification circuit, rc filter circuit and control integrated circuit respectively with lamp state sample circuit, again:

Rectification circuit comprises MOSFET, as the AC/DC conversion;

Clock generating and lamp state sample circuit, clock signal is delivered to control integrated circuit, make it the time main pulse of the standard that produces, simultaneously, the of-state voltage of fluorescent lamp is delivered to control integrated circuit after by dividing potential drop, judge that thus lamp " is lighted " and " not lighting " two states;

Rc filter circuit is delivered to integrated circuit with the output voltage of described rectification circuit after through current limliting and filtering, so that the power supply of integrated circuit to be provided;

Control integrated circuit is as the control of the control of warm-up time and MOSFFT " opening " and " pass ", and this control integrated circuit is caught the peak value of the inductive current of this inductive type fluorescent lamp, and turn-offs described MOSFET when this inductive current reaches maximum.

2. the start-up control circuit of inductive type fluorescent lamp according to claim 1 is characterized in that; Described clock generating and lamp state sample circuit are made up of two resistance (R2, R3).

3. the start-up control circuit of inductive type fluorescent lamp according to claim 1 is characterized in that; Described rc filter circuit is made up of resistance (R1) and capacitance-resistance filter (C).