GB2544636A - Driving circuit with electromagnetic interference suppression - Google Patents
Driving circuit with electromagnetic interference suppression Download PDFInfo
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- GB2544636A GB2544636A GB1617802.2A GB201617802A GB2544636A GB 2544636 A GB2544636 A GB 2544636A GB 201617802 A GB201617802 A GB 201617802A GB 2544636 A GB2544636 A GB 2544636A
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- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 13
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- 239000003990 capacitor Substances 0.000 claims description 35
- 230000002238 attenuated effect Effects 0.000 claims 1
- 230000003993 interaction Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 12
- 230000001105 regulatory effect Effects 0.000 description 7
- 230000033228 biological regulation Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 229910052736 halogen Inorganic materials 0.000 description 3
- 150000002367 halogens Chemical class 0.000 description 3
- 238000009434 installation Methods 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/38—Switched mode power supply [SMPS] using boost topology
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
- H02M1/4225—Arrangements for improving power factor of AC input using a non-isolated boost converter
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Led Devices (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
A driving circuit 1 with electromagnetic interference suppression for driving a light source such as a light-emitting diode unit 2 comprises a driving unit 11, a power switching unit 14 and a constant current unit 16. The first terminal of an inductor L1 of the power switching unit is coupled with the driving unit; the second terminal thereof is coupled with a diode D1 and a first transistor Q1 respectively; the third terminal of the first transistor is coupled with a ground terminal; a first impedance element B1 is connected with the first terminal or the second terminal of the diode; a second impedance element B2 is connected with the first terminal or the third terminal of the first transistor; the first terminal of a third impedance element B3 is connected with the second terminal of the first transistor, and the second terminal of the third impedance element is coupled with the driving unit. Electromagnetic interference is suppressed by the impedance elements, which may be ferrite beads or resistances.
Description
DRIVING CIRCUIT WITH ELECTROMAGNETIC INTERFERENCE SUPPRESSION
EFFECT
Field of the Invention
The present invention relates to a driving circuit, and relates particularly to a driving circuit with an electromagnetic interference (EMI) suppression effect.
Background to the Invention
Although conventional halogen bulbs have a high level of brightness and are often used in spot lights and other light fittings, because their energy consumption is relatively great (for example, 50 W), they have been replaced gradually by low wattage (for example, 3 W - 10 W) light-emitting diode (LED) spot lights.
In a conventional kind of LED spot light, such as a standard MR16 (multifaceted reflector) LED spot light bulb, its driving circuit is not able to pass electromagnetic interference safety requirements (such as EN55015 class B or the relevant regulations in the country or countries in which the product will be sold), even exceeding the safety requirements by as much as 20 dB. At present, the problem of electromagnetic interference is commonly solved by a common mode choke (also known as a common mode inductor or common mode coil). However, at the current required by the original circuit, this kind of element is relatively bulky and cannot be placed in a standard MR16 (ANSI standard, for example, ANSI C78.1413-2001) light bulb. Also, snubber circuits are used to suppress electromagnetic interference caused by high frequency switching, but the impact on power efficiency after adding a snubber circuit is great, and the electromagnetic interference suppression effect is also rather limited (only 5-10 dB of suppression ability), which does not meet the requirements of the relevant safety regulations.
Summary of the invention
The purpose of the present invention is to provide a driving circuit with electromagnetic interference suppression to meet or exceed the electromagnetic interference safety requirements as set out in the relevant regulations in the country where the product will be sold. The driving circuit of the present invention can achieve an electromagnetic interference suppression effect under specific and restricted space requirements. Preferably, the electromagnetic interference suppression effects can also meet regulatory requirements. The invention extends to include an LED lamp or bulb incorporating a driving circuit as described.
In order to achieve the abovementioned purpose, a driving circuit with electromagnetic interference suppression according to the present invention is provided that drives a light-emitting unit to emit light, with the driving circuit comprising a driving unit, a power switching unit and a constant current unit. The power switching unit is coupled with the driving unit, and has an inductor, a diode, a first transistor, a first impedance element, a second impedance element and a third impedance element; the first terminal of the inductor is coupled with the driving unit; the second terminal thereof is coupled with the diode and the first transistor respectively; the third terminal of the first transistor is coupled with a ground terminal; the first impedance element is connected with the first terminal or the second terminal of the diode; the second impedance element is connected with the first terminal or the third terminal of the first transistor; the first terminal of the third impedance element is connected with the second terminal of the first transistor, and the second terminal of the third impedance element is coupled with the driving unit. The constant current unit is coupled with the power switching unit, driving unit and light-emitting unit respectively, and the driving unit controls the constant current output by the constant current unit to drive the light-emitting unit to emit light.
In one embodiment, the first impedance element is connected with between the second terminal of the inductor and the first terminal of the diode, the first terminal of the first transistor is connected with the second terminal of the inductor and the first terminal of the first impedance element respectively, and the second impedance element is connected with between the third terminal of the first transistor and the ground terminal.
In a further embodiment, the first impedance element is connected between the second terminal of the inductor and the first terminal of the diode, the first terminal of the second impedance element is connected with the second terminal of the inductor and the first terminal of the first impedance element respectively, the second terminal of the second impedance element is connected with the third terminal of the first transistor, and the third terminal of the first transistor is connected with the ground terminal.
In a still further embodiment, the second terminal of the inductor is connected with the first terminal of the diode and the first terminal of the first transistor respectively, the first impedance element is connected with between the second terminal of the diode and the constant current unit, and the second impedance element is connected with between the third terminal of the first transistor and the ground terminal.
In one embodiment, the second terminal of the inductor is connected with the first terminal of the diode and the first terminal of the second impedance element, the first impedance element is connected with between the second terminal of the diode and the constant current unit, the second terminal of the second impedance element is connected with the first terminal of the first transistor, and the third terminal of the first transistor is connected with the ground terminal.
In one embodiment, the first impedance element, second impedance element or third impedance element of the power switching unit is a ferrite bead or resistance.
In one embodiment, the inductor, diode, first transistor, first impedance element, second impedance element and third impedance element of the power switching unit together form an integrated circuit.
In one embodiment, the driving circuit further comprises a rectifier unit and a detector unit. The rectifier unit is coupled with the driving unit and power switching unit. The detector unit is coupled with the rectifier unit, power switching unit and driving unit respectively.
In one embodiment, the driving circuit further comprises a bleeder unit which is coupled with the power switching unit, constant current unit and driving unit respectively, and the bleeder unit is used together with a phase dimmer.
In one embodiment, the constant current unit has a first capacitor, a fourth impedance element and a fifth impedance element, the first terminal of the first capacitor is connected with the second terminal of the diode of the power switching unit and the first terminal of the fourth impedance element respectively, the second terminal of the fourth impedance element is connected with the first terminal of the light- emitting unit, the first terminal of the fifth impedance element is connected with the second terminal of the first capacitor, and the second terminal thereof is connected with the second terminal of the light-emitting unit.
In one embodiment, the constant current unit further has a first resistance, second resistance and second transistor, the first terminal of the first resistance is connected with the first terminal of the fifth impedance element and the second terminal of the first capacitor respectively, the second terminal thereof is connected with a first terminal of the second resistance and the driving unit respectively, the second terminal of the second transistor is connected with the ground terminal, and the second terminal and third terminal of the second transistor are coupled with the driving unit respectively.
In one embodiment, the constant current unit further has a third resistance and a second capacitor, the first terminal of the second capacitor is connected with the second terminal of the second transistor and the driving unit, the first terminal of the third resistance is connected with the third terminal of the second transistor and the driving unit respectively, and the second terminal thereof is connected with the ground terminal.
In one embodiment, the fourth impedance element or fifth impedance element is a ferrite bead or resistance.
In one embodiment, the driving circuit is used in a multifaceted reflector type light-emitting diode light bulb.
In summary, in the driving circuit of the present invention, as the main cause of electromagnetic interference comes from the operating frequency of the integrated circuit of the driving circuit being too high, problems generated by the power switching unit are also quite serious. Accordingly, by providing a plurality of impedance elements in the power switching unit, the present invention not only enables the driving circuit to meet the specific circuit space requirements of LED light bulbs, but can also achieve an electromagnetic interference suppression effect. In one embodiment, as well as providing a plurality of impedance elements in the power switching unit, a plurality of impedance elements are further provided in the constant current unit; the specific circuit space requirements of light bulbs can be met in the same way, and the electromagnetic interference suppression effect is further enabled to meet regulatory requirements.
Brief description of the drawings
Drawing 1 is a functional block diagram of a driving circuit with electromagnetic interference suppression of a preferred embodiment of the present invention;
Drawing 2 A is a schematic circuit diagram of a driving circuit of one embodiment;
Drawing 2B is an enlarged schematic circuit diagram of the power switching unit of the driving circuit of Drawing 2A;
Drawings 2C to Drawing 2E are schematic circuit diagrams of the driving circuit of respective embodiments different from the preferred embodiment of the present invention;
Drawing 2F is an enlarged schematic circuit diagram of the constant current unit of the driving circuit of Drawing 2E;
Drawing 3A and Drawing 3B, Drawing 4A and Drawing 4B are line graphs of, in one embodiment of the present invention, electromagnetic interference at different operating frequencies before adding and after adding an impedance element to the driving circuit respectively.
Description of the Specific Embodiments
The following describes the driving circuit with electromagnetic interference suppression of a preferred embodiment of the present invention with reference to drawings, wherein the same elements are allocated the same reference numerals. Referring to Drawing 1, Drawing 2A and Drawing 2B, wherein Drawing 1 is a functional block diagram of a driving circuit 1 with electromagnetic interference suppression of a preferred embodiment of the present invention, Drawing 2A is a schematic circuit diagram of a driving circuit 1 of one embodiment and Drawing 2B is an enlarged schematic circuit diagram of the power switching unit 14 of the driving circuit 1 of Drawing 2A._The driving circuit 1 of the present embodiment has an electromagnetic interference suppression function and can, but is not limited to, be used to drive a standard MR type light-emitting diode light bulb, whereby the driving circuit comprises at least one light-emitting unit 2 of a light-emitting diode emitting light. As the circuit installation space of an MR16 light bulb is relatively limited, the driving circuit 1 thus has specific limitations in terms of spatial dimensions. Herein, “MR” stands for multifaceted reflector, and MR16 expresses that the front diameter of said light bulb is two inches (namely, the diameter is approximately 5 centimetres in length). In other words, under the specific space requirements of MR16 light bulbs, the driving circuit 1 of the present embodiment is able to achieve an electromagnetic interference (EMI) suppression effect and, even better, can also meet the requirements of safety regulations. However, in different embodiments, the driving circuit 1 can also be applied to other types of light-emitting diode light bulbs and is not limited to only being applied to standard MR type light-emitting diode light bulb circuits.
As is shown in Drawing 1, the driving circuit 1 comprises a driving unit 11, a power switching unit 14 and a constant current unit 16. In addition, the driving circuit 1 of the present embodiment further comprises a rectifier unit 12, a detector unit 13 and a bleeder unit 15. Herein, the term “coupled” can mean a physical electrical connection, or a physical electrical connection through other elements, or a non-physical signal connection, and is not intended to have a limited meaning. In addition, “connected” can be a direct connection of a physical element, or an indirect connection through other elements, and again is not limited.
As is shown in Drawing 1, the driving unit 11 is coupled with a rectifier unit 12, a detector unit 13, a power switching unit 14, a bleeder unit 15 and a constant current unit 16 respectively, and outputs a control signal to control the detector unit 13, power switching unit 14 and constant current unit 16, thereby controlling the constant current unit 16 outputting a constant current to drive the light-emitting unit 2 to emit light. In the present embodiment, the driving unit 11 is a circuit comprising an integrated circuit (labelled as IC1), four capacitors (labelled as C6, C7, Cvcc and Coff) and a resistance (labelled as Roff), the relationship between the links of which can be seen in Drawing 2A, and, as persons skilled in the art will be able to clearly understand from the schematic circuit diagram of Drawing 2A the connection relationship of these elements, this is not repeated.
The rectifier unit 12 is coupled with the driving unit 11, detector unit 13 and power switching unit 14, and can receive an input voltage. Herein, the input voltage can vary according to the design requirements of the rectifier unit 12 and light-emitting unit 2 (different embodiments may have different input voltages); in one embodiment, the input voltage is, for example, alternating current (AC) 12 V or direct current (DC) 12 V; in a different embodiment, the input voltage may also be another voltage value, and is not limited, depending on the specifications of the rectifier unit 12 and the requirements and specification of the LED of the light-emitting unit 2. Herein, after the input voltage has been rectified by the rectifier unit 12, direct current electricity can be obtained and input to the detector unit 13. The rectifier unit 12 of the present embodiment is a full wave rectifier unit, and can be a bridge rectifier, as shown in Drawing 2A, which comprises four diodes DB1-DB4; as the connection relationship of the bridge rectifier (DB1-DB4) is conventional, there will be no further description of this.
The detector unit 13 is a circuit comprising three capacitors (labelled as C3, C4 and C5), three resistances (labelled as R4, R5 and R6), one diode (labelled as D2) and one transistor (labelled as Q3). Herein, one terminal of the transistor Q3 is connected with the rectifier unit 12 and power switching unit 14 through the capacitor C3, and another terminal of the transistor is coupled with the power switching unit 14 and integrated circuit IC1 of the driving unit 11 (pin 3). In addition, the control terminal (gate) of the transistor Q3 is connected with the capacitor C4 and resistance R4, and connected with the integrated circuit IC1 of the driving circuit 11 (pin 4), so as to receive the control of the integrated circuit IC1 and be turned on or off. Also, the anode of the diode D2 is connected with the integrated circuit IC1 (pin 5) through the resistance R5 and connected with the resistance R6 and capacitor C6 respectively, and the cathode of the diode D2 is connected with an input terminal and the diode DB4 of the rectifier unit 12. Drawing 2A sets out the detailed connection relationship of the elements of the detector unit 13.
The rectifier unit 12 and the detector unit 13 of the present embodiment are provided to solve transformer compatibility problems, with this compatibility referring to the original transformer being provided for use, for example, with a 50 W halogen bulb. However, when driving the light-emitting unit 2 with an LED, as the load characteristics are different and power is also lower (for example, 3 W-10 W), when using a circuit originally used for halogen lights and connecting it to drive the light-emitting unit 2 with an LED, this may cause the LED to be unable to be turned on or to flicker. Accordingly, the present embodiment requires the addition of the rectifier unit 12 and detector unit 13 so as to overcome the problems of the LED being unable to be turned on or flickering. In different embodiments, it may not be necessary to provide the rectifier unit 12 and detector unit 13.
In addition, and referring to Drawing 2A and Drawing 2B, wherein the power switching unit 14 is coupled with the driving unit 11, rectifier unit 12, detector unit 13, bleeder unit 15 and constant current unit 16 respectively. The power switching unit 14 of the present embodiment has an inductor L1, a diode D1, a first transistor Q1, a first impedance element B1, a second impedance element B2 and a third impedance element B3. Also, the power switching unit 14 has a resistance R0.
The first terminal of the inductor L1 is coupled with the driving unit 11, the second terminal thereof is coupled with the diode D1 and first transistor Q1 respectively, and the third terminal of the first transistor Q1 is coupled with a ground terminal. In addition, the first impedance element B1 is connected with the first terminal and the second terminal of the diode D1, the second impedance element B2 is connected with the first terminal and the third terminal of the first transistor Q1, a first terminal of the third impedance element B3 is connected with a second terminal of the first transistor Q1, and the second terminal of the third impedance element B3 is coupled with the driving unit 11.
In the present embodiment, the first terminal of the inductor L1 is coupled with the driving unit 11 through the detector unit 13. In this way, the first terminal of the inductor L1 is connected with one terminal of the capacitor C3 of the detector unit 13 and the output terminal (cathode of the diode DB3) of the rectifier unit 12, so that the signal output by the output terminal of the rectifier unit 12 can be received by the inductor L1, the second terminal of the inductor L1 is connected with the first terminal of the first impedance element B1 and the first terminal of the first transistor Q1, and the first impedance element B1 is connected with between the second terminal of the inductor L1 and the first terminal of the diode D1 (anode). In addition, the first terminal of the first transistor Q1 is connected with the second terminal of the inductor L1 and the first terminal of the first impedance element B1 respectively, and the second impedance element B2 is connected with between the third terminal of the first transistor Q1 and the ground terminal.
In addition, the second terminal (cathode) of the diode D1 is connected with the bleeder unit 15, integrated circuit IC1 (pin 14) of the driving unit 11 and the constant current unit 16 respectively. Additionally, the second terminal (control terminal, gate) of the first transistor Q1 is connected with the first terminal of the third impedance element B3, and the second terminal of the third impedance terminal B3 is connected with the integrated circuit IC1 (pin 1) of the driving unit 11. Furthermore, the first terminal of the resistance RO is connected with the third terminal of the transistor Q3 of the detector unit 13 and the integrated circuit IC1 (pin 3) of the driving unit 11 respectively, and the second terminal thereof is connected with the second terminal of the second impedance element B2, the integrated circuit IC1 (pins 2, 12) of the driving unit 11 and the ground terminal.
The integrated circuit IC1 of the driving unit 11 outputs high frequency switching signals, for example, but not limited to, pulse width modulation (PWM) signals controlling the first transistor Q1 working in the on/off regions, so as to control the switching operation of the first transistor Q1, and then, through the energy storage of the inductor L1, providing the voltage and current required to drive the light-emitting unit 2; the high operating frequency of the integrated circuit IC1 will cause the problem of the driving circuit 1 generating electromagnetic interference. The power switching unit 14 of the present embodiment is thus in a boost circuit architecture and electromagnetic interference is suppressed through adding three impedance elements (the first impedance element B1, second impedance element B2 and third impedance element B3).
The first impedance element B1, or the second impedance element B2, or the third impedance element B3 may be a ferrite bead or a resistance. The present embodiment is an example such that the first impedance element B1, second impedance element B2 and third impedance element B3 respectively are ferrite beads. Ferrite beads are elements composed of a type of ferrite alloy powder, and alloy materials will affect the frequency band of the filter action; when electromagnetic interference enters the surface of this ferrite bead material, it will form a very thin magnetic wall on the surface of the element, and the magnetic material on the inside of the wall will generate friction between molecules because of the electromagnetic energy entering the outside and forming a spin precession effect, whereby the energy of the electromagnetic interference is transformed into thermal energy and dissipated. By adding the first impedance element B1, second impedance element B2 and third impedance element B3 into the power switching unit 14, the present embodiment can suppress high frequency electromagnetic interference signals. In addition, in one embodiment, the first impedance element B1, second impedance element B2 and third impedance element B3 can combine with the inductor L1, diode D1, first transistor Q1 and resistance RO to form one integrated circuit (namely, combining the elements of the power switching unit 14 and making an integrated circuit IC), thereby reducing the use of space and being better able to conform to the circuit installation space of MR16 light bulbs.
In addition, the bleeder unit 15 is coupled with the power switching unit 14, constant current unit 16 and driving unit 11 respectively. The bleeder unit 15 is mainly equipped with a silicon-controlled rectifier (TRIAC) phase dimmer. In other words, the bleeder unit 15 enables the LED driver to be compatible with the dimmer of the silicon-controlled rectifier so as to achieve the purpose of dimming. The bleeder unit 15 of the present embodiment is a resistance R4, one terminal of the resistance R4 is connected with the cathode of the diode D1 of the power switching unit 14, the capacitor C6, one terminal of the capacitor C7 and the constant current unit 16 respectively, and another terminal of the resistance R4 is connected with the integrated circuit IC1 (pin 15) of the driving unit 11. In another embodiment, it is also possible not to provide the bleeder unit 15.
The constant current unit 16 is coupled with the bleeder unit 15, power switching unit 14, driving unit 11 and light-emitting unit 2 respectively, and the driving unit 11 can control the constant current unit 16 to output a constant current to drive the light-emitting unit 2 to emit light. As is shown in Drawing 2A, the constant current unit 16 of the present embodiment has a first capacitor C1, a first resistance R1, a second resistance R2, a third resistance R3, a second transistor Q2 and a third capacitor C2. The first capacitor Q1, second capacitor Q2 and third capacitor Q3 of the present embodiment may be, for example but not limited to, an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) respectively.
The first terminal of the first capacitor C1 is connected with the second terminal of the diode D1 of the power switching unit 14 and the first terminal or positive electrode of the light-emitting unit 2 respectively and the second terminal of the first capacitor C1 is connected with the first terminal of the first resistance R1, the first terminal of the second transistor Q2 and the second terminal (negative electrode) of the light-emitting unit 2 respectively. In addition, the second terminal of the first resistance R1 is connected with the first terminal of the second resistance R2 and the integrated circuit IC1 (pin 11) of the driving unit 11 respectively, the second terminal of the second resistance R2 is connected with the integrated circuit IC1 (pin 12) of the driving unit 11 and the ground terminal respectively, and the second terminal (control terminal, gate) and the third terminal of the second transistor Q2 are coupled with the integrated circuit IC1 (pin 9, pin 10) respectively. Furthermore, the first terminal of the second capacitor C2 is connected with the second terminal (control terminal, gate) of the second transistor Q2 and the integrated circuit IC1 (pin 9) of the driving unit 11, the first terminal of the third resistance R3 is connected with the third terminal of the second transistor Q2 and the integrated circuit IC1 (pin 10) of the driving unit 11 respectively, and the second terminal thereof is connected with the ground terminal and the integrated circuit IC1 (pin 12).
In the present embodiment, the control terminal (gate) of the second transistor (Q2) receives the control of the integrated circuit IC1 and operates in its linear region, and, on the basis of the channel ratio of the gate input current opening the second transistor Q2, the current flowing from the second terminal to the third terminal of the second transistor Q2 is caused to be a constant current, thereby causing the current flowing through the light-emitting unit 2 to be a constant current, and thereby driving the light-emitting unit 2 to emit light.
In addition, referring to Drawing 2C and Drawing 2D, these illustrate schematic circuit diagrams of the driving circuit 1a, 1b of different embodiments of the present invention.
As is shown in Drawing 2C, the first impedance element B1 of the power switching unit 14a of the driving circuit 1a is, in the same way, connected between the second terminal of the inductor L1 and the first terminal of the diode D1, but a major difference from the driving circuit 1 of Drawing 2A is that the first terminal of the second impedance element B2 of the power switching unit 14a is connected with the second terminal of the inductor L1 and the first terminal of the first impedance element B1 respectively, the second terminal of the second impedance element B2 is connected with the second terminal of the first transistor Q1, and the third terminal of the first transistor Q1 is connected with the ground terminal and the second terminal of the resistance R0.
In addition, as shown in Drawing 2D, the second impedance element B2 of the power switching unit 14b of the driving circuit 1b is, in the same way, connected with between the third terminal of the first transistor Q1 and the ground terminal, but a major difference from the driving circuit 1 of Drawing 2A is that the second terminal of the inductor L1 of the power switching unit 14b is connected with the first terminal of the diode D1 and the first terminal of the first transistor Q1, and the first impedance element B1 is connected with the second terminal (cathode) of the diode D1 and between the bleeder unit 15 and constant current unit 16.
In addition, as the same elements of the driving circuit 1 can be referred to for the other technical features of the driving circuit 1a, 1b, these are not repeated. It should be further mentioned that, in another embodiment (not shown in the drawings), the first impedance element B1 of the driving circuit can be connected between the second terminal of the diode D1 and the constant current unit 16, the second terminal of the inductor L1 can be connected with the first terminal of the diode D1 and the first terminal of the second impedance element B2 respectively, the second terminal of the second impedance element B2 is connected with the first terminal of the first transistor Q1, and the third terminal of the first transistor Q1 is connected with the ground terminal. In other words, in a different embodiment, with respect to the driving circuit 1b, when the second impedance element B2 is connected between the second terminal of the inductor L1 (and the first terminal of the diode D1) and the first terminal of the first transistor Q1, the driving circuit also has, in the same way, an electromagnetic interference suppression effect.
In addition, referring to Drawing 2E and Drawing 2F respectively, wherein Drawing 2E is a schematic circuit diagram of the driving circuit 1c of another embodiment of the preferred embodiment of the present invention, and Drawing 2F is an enlarged schematic circuit diagram of the constant current unit 16c of the driving circuit 1c of Drawing 2E.
As is shown in Drawing 2E and Drawing 2F, with respect to the driving circuit 1 of Drawing 2A, a major difference of the driving circuit 1c of the present embodiment from the driving circuit 1 of Drawing 2A is that, as well as the constant current unit 16c of the driving circuit 1c having the first capacitor C1, first resistance R1, second resistance R2, third resistance R3, second transistor Q2 and second capacitor C2, the constant current unit 16c of the present embodiment further has a fourth impedance element B4 and a fifth impedance element B5. Herein, the first terminal of the first capacitor C1 is connected with the second terminal of the diode D1 of the power switching unit 14 and the first terminal of the fourth impedance element B4 respectively, the second terminal of the fourth impedance element B4 is connected with the first terminal (positive electrode) of the light-emitting unit 2, the first terminal of the fifth impedance element B5 is connected with the second terminal of the first capacitor C1, and the second terminal thereof is connected with the second terminal (negative electrode) of the light-emitting unit 2. In addition, the first terminal of the first resistance R1 is connected with the first terminal of the fifth impedance element B5 and the second terminal of the first capacitor C1, the second terminal thereof is connected with the first terminal of the second resistance R2 and the integrated circuit IC1 (pin 11) of the driving unit 11 respectively, the second terminal of the second resistance R2 is connected with the integrated circuit IC1 (pin 12) of the driving unit 11, and the second terminal (control terminal, gate) and the third terminal of the second transistor Q2 are coupled with the integrated circuit IC1 (pin 9, pin 10) respectively. Furthermore, the first terminal of the second capacitor C2 is connected with the second terminal (control terminal, gate) of the second transistor Q2 and the integrated circuit IC1 (pin 9) of the driving unit 11, and the first terminal of the third resistance R3 is connected with the third terminal of the second transistor Q2 and the integrated circuit IC1 (pin 10) of the driving unit 11, and the second terminal thereof is connected with the ground terminal.
In the same way, the gate of the second terminal Q2 of the present embodiment receives the control of the integrated circuit IC1 and operates in its linear region, and, on the basis of the channel ratio of the gate input current opening the second transistor Q2, the current flowing from the second terminal to the third terminal of the second transistor Q2 is caused to be a constant current, thereby causing the current flowing through the light-emitting unit 2 to be a constant current, and thereby driving the light-emitting unit 2 to emit light. However, as the integrated circuit IC1 controls the second transistor Q2, there will be the problem of electromagnetic interference being generated and, therefore, the present embodiment suppresses the problem of electromagnetic interference generated by the second transistor Q2 by adding two impedance elements B4, B5 in the constant current unit 16c. The fourth impedance element B4 or fifth impedance element B5 may be a ferrite bead or resistance. The present embodiment is an example where the fourth impedance element B4 and fifth impedance element B5 respectively are preferably ferrite beads.
In addition, referring to Drawing 3A to Drawing 4B, wherein Drawing 3A and Drawing 3B, Drawing 4A and Drawing 4B are line graphs of, in one embodiment of the present invention, electromagnetic interference at different operating frequencies before adding impedance elements (B1-B5) and after adding impedance elements (namely the driving circuit 1c of Drawing 2E) to the driving circuit respectively. Herein, Drawing 3A and Drawing 3B are line graphs showing horizontal performance electromagnetic waves, and Drawings 4A and 4B are line graphs showing vertical performance electromagnetic waves.
As is shown in Drawing 3A, the line L is the safety standard for MR16 type LED light bulbs at different frequencies. In terms of horizontal performance measurements, before adding the impedance elements (B1-B5), the peaks (points 1-5) of electromagnetic waves generated at different operating frequencies by the integrated circuit IC1 of the driving circuit were all in excess of the line L (safety standard), and the maximum value (point 5) reached 23.99 dB in excess. However, as is shown in Drawing 3B, after providing three impedance elements (B1, B2, B3) in the power switching circuit 14 and providing two impedance elements (B4, B5) in the constant current unit 16c, the maximum of the peaks (points 1-3) of electromagnetic waves generated at different operating frequencies was only around 24 dB, and all were lower than regulatory requirements.
In addition, as is shown in Drawing 4A, in terms of vertical performance measurements, before adding the impedance elements (B1-B5, ferrite beads), the peaks (points 1-7) of electromagnetic waves generated at different operating frequencies by the driving circuit were all in excess of the safety standard, and the maximum value (point 7) reached 19.75 dB in excess. However, as is shown in Drawing 4B, after providing three impedance elements (B1, B2, B3) in the power switching circuit 14 and providing two impedance elements (B4, B5) in the constant current unit 16c, the maximum of the peaks (points 1-4) of electromagnetic waves generated at different operating frequencies was only around 30 dB, conforming to regulatory requirements.
Preferred values for the impedances for impedances B1, B2 and B3 are as follows:-B1 : Impedance range 100Ω @ 100 MHz to 150Ω @ 100 MHz; B2 : Impedance range : 0Ω @ 100 MHz to 50Ω @ 100 MHz; B2 : Impedance range : 40Ω @100 MHz to 100Ω @100 MHz.
Accordingly, in the driving circuits 1, 1a-1c of the present embodiment, as a main cause of electromagnetic interference arises from the operating frequency of the integrated circuit IC1 of the driving circuit 11 being too high, and the problem of EMI generated in the power switching unit and constant current unit is relatively severe, therefore, in the driving circuits 1, 1a, 1b, through correspondingly providing three impedance elements (B1, B2, B3) in the power switching units 14, 14a, 14b, and, in the driving circuit 1c, providing two impedance elements (B4, B5) in the constant current unit 16c, not only are the driving circuits 1, 1a-1c enabled to meet the specific space requirements of MR16 LED light bulbs, but they are also able to achieve an electromagnetic interference suppression effect, and, in the embodiment of the driving circuit 1c, the electromagnetic interference suppression effect is further able to meet regulatory requirements.
Furthermore, as an additional explanation, when the circuit of the original light-emitting unit 2 is not provided with any of the abovementioned impedance elements B1-B5, then the EMI will exceed the regulatory standard by around between 20 and 30 dB. If, such as in the conventional technology, EMI is suppressed through a common choke, although there is the effect of EMI suppression, it is not possible to place the whole of the driving circuit into a standard MR16 light bulb. If a snubber circuit is added to suppress EMI, then, not only is the impact on light-emitting efficiency relatively great, but the electromagnetic interference suppression effect is also rather limited (only 5-10 dB of suppression ability), which does not meet the requirements of safety regulations. However, through the circuit design of composite elements of the present invention, not only can the circuit elements be placed into a standard MR16 type light bulb, but can also solve the problem of excessive EMI. Furthermore, in the abovementioned power switching units 14, 14a, 14b, impedance elements B1-B3 can, together with other elements, form an integrated circuit (namely, combining the elements of the power switching unit 14 and making an integrated circuit IC), thereby reducing the use of space. In addition, as the circuit installation space of an MR16 LED light bulb is relatively limited, in the embodiment, the driving circuits 1, 1a-1c use four layers, and, in the future, if smaller elements are used or an IC with composite external parts or a transistor is used, then it will not be limited to the use of four layers, and it may be simplified to, for example, two layers.
In summary, in the driving circuit of the present invention, as the main cause of electromagnetic interference comes from the operating frequency of the integrated circuit of the driving circuit being too high, problems generated by the power switching unit are also quite serious. Accordingly, by providing a plurality of impedance elements in the power switching unit, the present invention not only enables the driving circuit to meet the specific circuit space requirements of light bulbs, but can also achieve an electromagnetic interference suppression effect. In one embodiment, as well as providing a plurality of impedance elements in the power switching unit, a plurality of impedance elements are further provided in the constant current unit; the specific circuit space requirements of light bulbs can be met in the same way, and the electromagnetic interference suppression effect of the driving circuit is further enabled to meet regulatory requirements.
The above is only exemplary and is not limiting. Any changes and modifications that do not depart from the spirit and scope of the present invention and that have the same level of effect shall be included in the accompanying Claims.
Description of reference numerals used in the Drawings 1, 1a-1c: driving circuit 11: driving unit 12: rectifier unit 13: detector unit 14, 14a, 14b: power switching unit 15: bleeder unit 16, 16c: constant current unit 2: light-emitting unit B1: first impedance element B2: second impedance element B3: third impedance element B4: fourth impedance element B5: fifth impedance element C1-C7, Coff, Cvcc: capacitor D1, D2, DB1-DB4: diode IC1: integrated circuit 1-16 on IC1: integrated circuit pin L: line (safety regulation standard) L1: inductor Q1-Q3: transistor RO, R1-R6, Roff: resistance
Vcc: operating voltage VP: endpoint voltage 1-7 on the curve: point (peak)
Claims (16)
1. A driving circuit with electromagnetic interference suppression that drives a light-emitting unit to emit light, with said driving circuit comprising: a driving unit; a power switching unit, coupled with said driving unit, and having an inductor, a diode, a first transistor, a first impedance element, a second impedance element and a third impedance element; the first terminal of said inductor is coupled with said driving unit; the second terminal of said inductor is coupled with said diode and said first transistor respectively; the third terminal of said first transistor is coupled with the ground terminal; said first impedance element is connected with the first terminal or second terminal of said diode; said second impedance element is connected with the first terminal or third terminal of said first transistor; the first terminal of said third impedance element is connected with the second terminal of said first transistor, and the second terminal of said third impedance element is coupled with said driving unit; and a constant current unit is coupled with said power switching unit, said driving unit and said light-emitting unit respectively, and said driving unit controls a constant current output by said constant current unit to drive said light-emitting unit to emit light; wherein said power switching unit is in a boost circuit architecture and electromagnetic interference is suppressed by said three impedance elements, and an interaction between said driving unit, said first transistor, and said inductor attenuates a high-frequency signal and suppresses electromagnetic interference.
2. A driving circuit according to Claim 1, wherein said first impedance element is connected with between the second terminal of said inductor and the first terminal of said diode, the first terminal of said first transistor is connected with the second terminal of said inductor and the first terminal of said first impedance element respectively, and said second impedance element is connected with between the third terminal of said first transistor and said ground terminal.
3. A driving circuit according to Claim 1, wherein said first impedance element is connected with between the second terminal of said inductor and the first terminal of said diode, the first terminal of said second impedance element is connected with the second terminal of said inductor and the first terminal of said first impedance element respectively, the second terminal of said second impedance element is connected with the third terminal of said first transistor, and the third terminal of said first transistor is connected with said ground terminal.
4. A driving circuit according to Claim 1, wherein the second terminal of said inductor is connected with the first terminal of the diode and the first terminal of said first transistor respectively, said first impedance element is connected with between the second terminal of said diode and said constant current unit, and said second impedance element is connected with between the third terminal of said first transistor and said ground terminal.
5. A driving circuit according to Claim 1, wherein the second terminal of said inductor is connected with the first terminal of said diode and the first terminal of said second impedance element, said first impedance element is connected with between the second terminal of said diode and said constant current unit, the second terminal of said second impedance element is connected with the first terminal of said first transistor, and the third terminal of said first transistor is connected with said ground terminal.
6. A driving circuit according to any preceding claim, wherein said first impedance element, said second impedance element or said third impedance element of the power switching unit is a ferrite bead or resistance.
7. A driving circuit according to any preceding claim, wherein said inductor, said diode, said first transistor, said first impedance element, said second impedance element and said third impedance element of said power switching unit together form an integrated circuit.
8. A driving circuit according to any preceding claim further comprising: a rectifier unit which is coupled with said driving unit and said power switching unit respectively; and a detector unit which is coupled with said rectifier unit, said power switching unit and said driving unit respectively.
9. A driving circuit according to any preceding claim further comprising:- a bleeder unit which is coupled with said power switching unit, said constant current unit and said driving unit respectively, and said bleeder unit is used together with a phase dimmer.
10. A driving circuit according to Claim 1, wherein said constant current unit has a first capacitor, a fourth impedance element and a fifth impedance element, the first terminal of said first capacitor is connected with the second terminal of said diode of said power switching unit and the first terminal of said fourth impedance element respectively, the second terminal of said fourth impedance element is connected with the first terminal of said light-emitting unit, the first terminal of said fifth impedance element is connected with the second terminal of said first capacitor, and the second terminal of said second transistor is connected with the second terminal of said light-emitting unit.
11. A driving circuit according to Claim 10, wherein said constant current unit further has a first resistance, second resistance and second transistor, the first terminal of said first resistance is connected with the first terminal of said fifth impedance element and the second terminal of said first capacitor respectively, the second terminal of said first resistance is connected with the first terminal of said second resistance and said driving unit respectively, the second terminal of said second transistor is connected with said ground terminal, and the second terminal and third terminal of said second transistor are coupled with said driving unit respectively.
12. A driving circuit according to Claim 11, wherein said constant current unit further has a third resistance and a second capacitor, the first terminal of said second capacitor is connected with the second terminal of said second transistor and said driving unit, the first terminal of said third resistance is connected with the third terminal of said second transistor and said driving unit respectively, and the second terminal of said third resistance is connected with said ground terminal.
13. A driving circuit according to any preceding claim wherein the range of values for the impedances B1, B2 and B3 are as follows:- B1 : Impedance range 100Ω @ 100 MHz to 150Ω @ 100 MHz; B2 : Impedance range : 0Ω @ 100 MHz to 50Ω @ 100 MHz; B2 : Impedance range : 40Ω @ 100 MHz to 100Ω @100 MHz.
14. A driving circuit according to Claim 10 wherein said fourth impedance element or said fifth impedance element is a ferrite bead or resistance.
15. A light-emitting diode light bulb comprising: a housing; a light-emitting unit provided in said housing: and a driving circuit according to any of Claims 1 to 14 inclusive.
16. An LED Lamp including a driving circuit comprising: impedances B1, B2 and B3; wherein one of these alternatives happens: IC1, Q1, and L1 interact to be attenuated on high-frequency signal and suppress EMI.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TW104134591A TWI584688B (en) | 2015-10-21 | 2015-10-21 | Driving circuit with suppressing electromagnetic interference |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201617802D0 GB201617802D0 (en) | 2016-12-07 |
| GB2544636A true GB2544636A (en) | 2017-05-24 |
| GB2544636B GB2544636B (en) | 2020-01-22 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1617802.2A Expired - Fee Related GB2544636B (en) | 2015-10-21 | 2016-10-21 | Driving circuit with electromagnetic interference suppression effect |
Country Status (4)
| Country | Link |
|---|---|
| AU (1) | AU2016340352A1 (en) |
| GB (1) | GB2544636B (en) |
| TW (1) | TWI584688B (en) |
| WO (1) | WO2017068531A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108575007B (en) * | 2017-03-10 | 2024-09-03 | 常州星宇车灯股份有限公司 | Dimming and brightening processing device of LED constant current circuit based on indoor lamp gate control gear |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110148318A1 (en) * | 2008-11-28 | 2011-06-23 | Lightech Electronic Industries Ltd. | Phase controlled dimming led driver system and method thereof |
| US20120112653A1 (en) * | 2009-07-30 | 2012-05-10 | Osram Ag | Electronic ballast for operating at least one discharge lamp |
| CN103619089A (en) * | 2013-09-11 | 2014-03-05 | 杭州电子科技大学 | EMI inhibiting method of LED driving power supply |
| CN103618442A (en) * | 2013-09-11 | 2014-03-05 | 杭州电子科技大学 | EMI inhibiting method of LED driving power supply |
| US20140368419A1 (en) * | 2013-06-13 | 2014-12-18 | Hon Hai Precision Industry Co., Ltd. | Backlight driving module and liquid crystal display using the same |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008044372A1 (en) * | 2008-12-05 | 2010-06-10 | Robert Bosch Gmbh | Switching arrangement for lighting device, has lighting unit and electronic control gear, where electronic control gear has switch transistor |
| US20120043893A1 (en) * | 2010-06-28 | 2012-02-23 | Innosys, Inc. | Dimmable LED Power Supply |
| TWM420634U (en) * | 2011-08-12 | 2012-01-11 | Espower Electronics Inc | Driving system of LED light tube and light tube thereof |
| US9485815B2 (en) * | 2012-12-19 | 2016-11-01 | Shenzhen China Star | Backlight driving circuit and liquid crystal display with the same |
| TWI564688B (en) * | 2013-03-04 | 2017-01-01 | 英諾系統公司 | Variable resistance for driver circuit dithering |
| JP2015065040A (en) * | 2013-09-25 | 2015-04-09 | 東芝ライテック株式会社 | Power supply unit and illumination device |
| WO2015080467A1 (en) * | 2013-11-26 | 2015-06-04 | 엘지이노텍 주식회사 | Power apparatus for led lighting |
-
2015
- 2015-10-21 TW TW104134591A patent/TWI584688B/en not_active IP Right Cessation
-
2016
- 2016-10-21 WO PCT/IB2016/056325 patent/WO2017068531A1/en active Application Filing
- 2016-10-21 GB GB1617802.2A patent/GB2544636B/en not_active Expired - Fee Related
- 2016-10-21 AU AU2016340352A patent/AU2016340352A1/en not_active Abandoned
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110148318A1 (en) * | 2008-11-28 | 2011-06-23 | Lightech Electronic Industries Ltd. | Phase controlled dimming led driver system and method thereof |
| US20120112653A1 (en) * | 2009-07-30 | 2012-05-10 | Osram Ag | Electronic ballast for operating at least one discharge lamp |
| US20140368419A1 (en) * | 2013-06-13 | 2014-12-18 | Hon Hai Precision Industry Co., Ltd. | Backlight driving module and liquid crystal display using the same |
| CN103619089A (en) * | 2013-09-11 | 2014-03-05 | 杭州电子科技大学 | EMI inhibiting method of LED driving power supply |
| CN103618442A (en) * | 2013-09-11 | 2014-03-05 | 杭州电子科技大学 | EMI inhibiting method of LED driving power supply |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2017068531A1 (en) | 2017-04-27 |
| GB201617802D0 (en) | 2016-12-07 |
| GB2544636B (en) | 2020-01-22 |
| TWI584688B (en) | 2017-05-21 |
| AU2016340352A1 (en) | 2018-06-07 |
| TW201715917A (en) | 2017-05-01 |
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| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20231021 |