CN201550327U

CN201550327U - Driving circuit of LED fluorescent tube

Info

Publication number: CN201550327U
Application number: CN200920238392XU
Authority: CN
Inventors: 樊邦扬
Original assignee: Heshan Lide Electronic Enterprise Co Ltd
Current assignee: Heshan Lide Electronic Enterprise Co Ltd
Priority date: 2009-10-31
Filing date: 2009-10-31
Publication date: 2010-08-11
Anticipated expiration: 2019-10-31

Abstract

The utility model discloses a driving circuit of an LED fluorescent tube which comprises a commercial power input end, an EMI filtering module, a rectifying module, a PFC correcting filtering module, a PI type filtering module, a DC-AC power converting module, a secondary rectifying filtering module and an LED load which are sequentially connected; the EMI filtering module comprises a differential mode inductance and a common mode inductance which are connected in order and a filter capacitor which is connected with the input end of the EMI filtering module in parallel. Compared with the prior art, the driving circuit adopts the EMI filtering module which simultaneously has the differential module inductance and the common mode inductance, thereby the driving circuit can effectively eliminate conducting electromagnetic interference of the differential mode and common mode, avoids the electromagnetic pollution of the circuit, increases the stability of the circuit and can smoothly pass the conducting test.

Description

A kind of drive circuit of LED fluorescent tube

[technical field]

The utility model relates to a kind of drive circuit, refers in particular to a kind of LED fluorescent lamp drive circuit.

[background technology]

LED is along with the development of electric and electronic technology, household electronic products is popularized day by day and is electronic, the prosperity day by day of radio and television, post and telecommunications and computer network, the complicated day by day and deterioration of electromagnetic environment makes Electro Magnetic Compatibility (the anti-EM5 of EMC electromagnetic interference EMI and the electromagnetism) problem of electrical and electronic product also be subjected to the pay attention to day by day of national governments and manufacturing enterprise.The Electromagnetic Compatibility of electronics, electric equipment products is very important quality index; it not only is related to the functional reliability and the safety in utilization of product itself; but also may have influence on the operate as normal of other equipment and system, be related to the protection problem of electromagnetic environment.

The full name of EMC (Electro Magnetic Compatibility) is Electro Magnetic Compatibility, it is defined as " equipment and system can operate as normal in its electromagnetic environment and not to environment in the ability of anything formation electromagnetic disturbance that can not bear " this definition comprises the meaning aspect two, at first, this equipment should be able to be under certain electromagnetic environment operate as normal, promptly this equipment should possess certain electromagnetic immunity degree (EMS); Secondly, the electromagnetic disturbance that this equipment self produces can not produce excessive influence, i.e. electromagnetic disturbance (EMI) to other electronic products.

For fear of the electromagnetic interference between LED fluorescent tube and other electrical equipment, make the drive circuit of LED fluorescent tube also must pass through conduction test satisfying under the prerequisite of safety requirements.But existing LED fluorescent tube drive circuit is eliminated the DeGrain of electromagnetic interference, and efficient is low, is difficult to pass through conduction test.

[utility model content]

In view of the above-mentioned technical problem that exists in the prior art, the purpose of this utility model is to provide a kind of drive circuit that can reduce electromagnetic interference effectively and pass through the LED fluorescent tube of conduction test.

In order to reach above-mentioned technical purpose, the technological means that the utility model adopted is a kind of drive circuit of LED fluorescent lamp, comprise that mains electricity input end, EMI filtration module, rectification module, a PFC of connecting successively correct filtration module, π type filtration module, DC-AC power conversion module, secondary rectification filtering module and LED load, described EMI filtration module comprises and filter capacitor and the differential mode inductance that is connected in turn and the common mode inductance of mains electricity input end parallel connection that the output of described common mode inductance is connected with the input of a rectification module.

The utility model has adopted the EMI filtration module that has differential mode inductance and common mode inductance simultaneously, can eliminate the Conducted Electromagnetic Interference of differential mode, common mode form effectively with respect to prior art, avoid the electromagnetic pollution of circuit, improved the stability of circuit, and can pass through conduction test smoothly.

Preferably, described common mode inductance is annular common mode inductance.

Preferably, the chip model that adopted of described DC-AC power conversion module is IW3620.

Preferably, a described rectification module adopts full-wave rectification, and the secondary rectification filtering module adopts halfwave rectifier.

Preferably, between described mains electricity input end and EMI filtration module, also be in series with overcurrent protection module.

Preferably, described overcurrent protection module is a Thermal Cutoffs.

Preferably, the inductance value of described differential mode inductance is 4.7 milihenries, and the specification of described common mode inductance is 9 * 5 * 4.

[description of drawings]

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

Fig. 2 is circuit theory diagrams of the present utility model.

[embodiment]

In order at length to set forth the technical solution of the utility model, be described in further detail below in conjunction with accompanying drawing.

As shown in Figure 1 and Figure 2: the utility model comprises that successively the mains electricity input end 1 that connects, EMI filtration module 3, rectification module 4, a PFC correct filtration module 5, π type filtration module 6, DC-AC power conversion module 7, secondary rectification filtering module 8 and LED load 9, and described EMI filtration module 3 comprises differential mode inductance L1 and common mode inductance L2 that connects in turn and the filter capacitor C that is connected in parallel on EMI filtration module 3 inputs; The preferred annular common mode inductance of above-mentioned common mode inductance L2, specification is 9 * 5 * 4; Described differential mode inductance L1 adopts the differential mode inductance of 4.7 milihenries; The model of the chip U that described DC-AC power conversion module 7 is adopted is IW3620; An above-mentioned rectification module 4 adopts full-wave rectification, and secondary rectification filtering module 8 adopts halfwave rectifier.

The course of work of circuit that the utility model adopts is as follows: civil power is by at first eliminating differential mode through EMI filtration module 3 behind the mains electricity input end 1, the Conducted Electromagnetic Interference of common mode form, then through rectification module 4 output DCs, correct filtration module 5 through PFC again and adjust the electric current of input and the phase difference between the voltage, and through the stable low harmonic current of π type filtration module 6 back outputs, and then the alternating current of process DC-AC power conversion module 7 output constant currents, through secondary rectification filtering module 8 alternating current is converted into direct current again and gives the LED load 9 power supplies, above-mentioned EMI filtration module 3 comprises differential mode inductance L1 and common mode inductance L2 that connects in turn and the filter capacitor C that is connected in parallel on EMI filtration module 3 inputs.

Circuit of the present utility model also is in series with overcurrent protection module 2 between mains electricity input end 1 and EMI filtration module 3, as shown in Figure 2, described overcurrent protection module 2 can be to be connected on Thermal Cutoffs F1 between mains electricity input end 1 and the EMI filtration module 3.

The utility model has adopted the EMI filtration module 3 that has differential mode inductance L1 and common mode inductance L2 simultaneously, can eliminate the Conducted Electromagnetic Interference of differential mode, common mode form effectively with respect to prior art, avoided the electromagnetic pollution of circuit, improve the stability of circuit, and can pass through conduction test smoothly.

Claims

1. the drive circuit of a LED fluorescent tube, comprise that mains electricity input end, EMI filtration module, rectification module, a PFC of connecting successively correct filtration module, π type filtration module, DC-AC power conversion module, secondary rectification filtering module and LED load, it is characterized in that: described EMI filtration module comprises and filter capacitor and the differential mode inductance that is connected in turn and the common mode inductance of mains electricity input end parallel connection that the output of described common mode inductance is connected with the input of a rectification module.

2. the drive circuit of LED fluorescent tube according to claim 1 is characterized in that: described common mode inductance is annular common mode inductance.

3. the drive circuit of LED fluorescent tube according to claim 1 is characterized in that: the chip model that described DC-AC power conversion module is adopted is IW3620.

4. according to the drive circuit of claim 1 or 2 or 3 described LED fluorescent tubes, it is characterized in that: a described rectification module adopts full-wave rectification, and the secondary rectification filtering module adopts halfwave rectifier.

5. the drive circuit of LED fluorescent tube according to claim 4 is characterized in that: also be in series with overcurrent protection module between described mains electricity input end and EMI filtration module.

6. the drive circuit of LED fluorescent tube according to claim 5 is characterized in that: described overcurrent protection module is a Thermal Cutoffs.

7. the drive circuit of LED fluorescent tube according to claim 4 is characterized in that: the inductance value of described differential mode inductance is 4.7 milihenries, and the specification of described common mode inductance is 9 * 5 * 4.