CN100521855C - Electronic ballast of inhibiting electromagnetic interference through double shielding - Google Patents
Electronic ballast of inhibiting electromagnetic interference through double shielding Download PDFInfo
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- CN100521855C CN100521855C CNB2006100499250A CN200610049925A CN100521855C CN 100521855 C CN100521855 C CN 100521855C CN B2006100499250 A CNB2006100499250 A CN B2006100499250A CN 200610049925 A CN200610049925 A CN 200610049925A CN 100521855 C CN100521855 C CN 100521855C
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Abstract
Present invention relates to high performance electromagnetic disturbance suppression electronic ballast. It contains said shell being double shielding construction consisting of outer layer shield and inner layer shield of each circuit unit shielding box, contacting section of outer layer shield metallic shell with cover board set elastic comb type piece, inner layer shield body with cover board using deep embedded insertion mode, signal interface connection using coaxial cable or wire with outer grounded metal tube, mains input connecting lamp tube output end through penetrate capacitor with grounded metallic shell, power supply EMI filter composed of multiple stage common mode, difference module LC passive low-pass filter, half bridge full bridge power inversion switch setting RC or RCD absorbing spike pulse loop and added with decouple filter network or decouple capacitor between half bridge midpoint and inversion direct current supply connection point with ground. Said invention has very high electromagnetic compatibility EMC, suitable for stringent specification electromagnetic disturbance protection in fluorescent lamp, halogen, and high voltage sodium lamp electronic ballast.
Description
Technical field
The present invention relates to electric source lighting electric ballast technical field, specifically is the electric ballast that a kind of dual shield suppresses electromagnetic interference.
Background technology
Produce electromagnetic noise interference EMI inevitably in the process of electric ballast HF switch work, its frequency range generally is hundreds of hertz to tens megahertz, and this frequency is the narrow band interference that disperses with repeat.Interference is carried out with free space radiation and two kinds of forms of electrical network conduction, its electric field, magnetic field can have a strong impact on normal operation near electronics, the telecommunication apparatus around, great-power electronic ballast produces high-intensity electromagnetic interference, even can make the components and parts of electronic equipment breakdown, cause permanent damage to lose efficacy.It is multiple that the analytical electron ballast produces the electromagnetic noise source, the power device of high-frequency inversion half-bridge or full-bridge switch, as double pole triode, field effect transistor, switching diode etc. when on off state uses, big spike appears in the moment of circuit debugging and shutoff, by circuit and device wire inductance thereof and distributed capacitance produce very big transient current, voltage forms electromagnetic noise interference, pulse repetition frequency height, the fast institute of the switching speed interference strength that produces are just big more.The diode rectification surge voltage produces and disturbs simultaneously, especially high-frequency rectification is because the junction capacitance Charge Storage, the recovery characteristics of charge carrier accumulating effect produces to be disturbed, inductance produces the reverse spike voltage pulse when switch disconnects and leakage field all can produce interference, and the high-frequency pulse current of passive power factor correcting circuit, Active Power Factor Correction pre-adjustment circuit is very big to the conduction influence that electrical network produces electromagnetic interference.The Conducted Electromagnetic Interference signal divides two kinds of common mode and differential modes, and wherein, it is bigger that common mode disturbances suppresses technical difficulty, and electric ballast product electromagnetic compatibility EMC index Design is careless slightly can pass through authentication requesting with regard to difficulty.
Summary of the invention
The purpose of this invention is to provide the electric ballast that a kind of dual shield is comprehensive, the degree of depth suppresses the electromagnetic noise interference of high-frequency inversion switch generation.
The technology of the present invention solution comprises metal-back, the power supply electromagnetic interface filter, rectification circuit and APFC or passive power factor correcting circuit, high-frequency pulse oscillator and its half-bridge or full bridge power inverse switch and overload protecting circuit, metal shell is made as the dual shield structure, by the ballast metal shell is that outer shielding and each circuit unit shielding box are that the internal layer shielding constitutes, outer shielded metal housing and cover plate contact portion are provided with elastic metallic pectination sheet, the dark intercalation mode of internal layer shield shell and cover plate, outer shielding is seamless with the housing of internal layer shielding, the corner is rounded, outer shielding is installed the isolation that certain space is arranged each other with the internal layer shielding, outer shielding shields only for some overlap joints with internal layer, outer shielded metal housing and the earth join, the ballast power input, the output that connects fluorescent tube penetrates metal shell by feed-through capacitor, electrode is a binding post in its electric capacity, the electric capacity external electrode closely is fixed on the metal shell, and internal layer shielding box signaling interface adopts the lead of coaxial cable or overcoat metal tube ground connection to connect;
Wherein, the power supply electromagnetic interface filter, rectification circuit and APFC or passive power factor correcting circuit, high-frequency pulse oscillator and half-bridge or full bridge power inverse switch and overload protecting circuit are provided with the internal layer shielding box respectively, its signaling interface adopts the lead of coaxial cable or overcoat metal tube ground connection to connect, half-bridge or full bridge power inverse switch also connect capacitance-resistance RC absorption spike potential circuit, or absorb the resistance of spike potential circuit and connect diode at RC, and half-bridge mid point over the ground and the direct current supply contact add decoupling filter network or decoupling capacitor between over the ground;
The power supply electromagnetic interface filter adopts multistage common mode, differential mode LC passive low ventilating filter to form, common mode inductance two-wire and on the coil rack of a closed magnetic circuit magnetic, end of the same name is unified to be input or output, the differential mode inductance coil rack coiling of E shape magnetic, its magnetic leaves air gap to inserting, common mode filtering electric capacity is by the high frequency feedthrough capacitor and connect on over the ground the big capacity shunt capacitance, metallic plate is set between the filters at different levels isolates.
The technical program electric ballast metal shell is made as the dual shield structure, screening effectiveness is than the obvious raising of individual layer, greatly place restrictions on the electromagnetic interference field intensity, and at power input, ballast connects the fluorescent tube output through the feedthrough capacitor high frequency bypass of metal shell for ground, prevent that electromagnetic interference from passing through transmission line leakage rediation and conduction, the power supply electromagnetic interface filter adopts multistage common mode, differential mode LC passive low ventilating filter is formed, further suppress the radiation and the conduction of electromagnetic interference, and at half-bridge or full bridge power inverse switch capacitance-resistance RC is set and absorbs the spike potential circuit, or absorb the resistance of spike potential circuit and connect diode at RC, half-bridge mid point over the ground and the direct current supply contact add decoupling filter network or decoupling capacitor between over the ground, thereby more intactly suppress the generation of electromagnetic interference.
Description of drawings
Fig. 1 is a dual shield structural representation of the present invention
Fig. 2 is a metal shell structural representation of the present invention
The handicapping of Fig. 3 inverse switch is held RC absorption circuit or is absorbed circuitous resistance and connect diode at RC
With reference to Fig. 1, the metal-back 2 of electric ballast of the present invention, EMI power filter 3, rectification circuit reach APFC or passive power factor correcting circuit 5, high-frequency pulse oscillator and its half-bridge or Full bridge power inverse switch and overload protecting circuit 7, metal shell 2 is made as the dual shield structure, by ballast Housing is that internal layer shielding 3,5,7 consists of for outer shielding 2 and each circuit unit shielding box, and outer shielding is golden Belong to housing 2 and be provided with elastic metallic pectination sheet 21 with cover plate 22 contact portions, internal layer shield shell 3,5,7 and That the dark intercalation mode of cover plate, the housing 3,5,7 of outer shielding 2 and internal layer shielding are is seamless, the corner is Circle, outer shielding 2 is installed the isolation that certain space is arranged each other with internal layer shielding 3,5,7, outer shielding 2 Shield 3,5,7 only for some overlap joints with internal layer, outer shielded metal housing 2 joins ballast with the earth Power input IN, the output OUT that connects fluorescent tube all penetrate in the metal shell 2 with through condenser 1,8, Its electric capacity 1,8 external electrodes closely are fixed on the metal shell, and electric capacity 1,8 interior electrodes are binding post, in Layer shielding box signaling interface adopts the lead 4,6 of coaxial cable or overcoat metal tube ground connection to connect.
Metal shell of the present invention is taked the dual shield structure, and usually, one deck shielding attenuation amount is only at tens of dB, When one deck shielding can not be satisfied shield effectiveness, particularly the great-power electronic ballast interference field was powerful, at it It is desirable that the outside adds one deck shielding again, establishes two layers of shielding and compares many joint attenuations with single-layer shield, can reach To the electromagnetic interference source electromagnetic field degree of depth that the high-frequency impulse switch is produced greater than the decay of 100dB place restrictions at shell In the body, the degree of depth prevents electromagnetic interference (EMI) emissions and conduction. The ectonexine shield shell is installed and is left between certain space Every the shielding of, ectonexine and be limited to a bit that overlap joint is the condition of dual shield necessity, not then lose that it is due Effect, outer shield shell and the earth join, and like this, can strengthen suppressing to disturb providing Electrical Safety again Ensure.
It is extremely important improving the lip-deep discontinuity of shield, and desirable screening model is not allow Offer hole, slit on the shield, otherwise the degradation shielding properties, and in the Practical Project such as the ballast electricity Source input, the output that connects fluorescent tube and heat dissipation ventilation unavoidably need perforate, therefore in its terminal interface Through condenser is set penetrates in the metal shell, its electric capacity external electrode closely is fixed on the metal shell, electric capacity Interior electrode is binding post, bypass High-frequency Interference first-harmonic and harmonic wave thereof, Leakage prevention.
Fig. 2 in order to prevent the slot leakage of housing 2 and cover plate 22, is provided with elastic metallic in its contact portion Pectination sheet 21, (a) among the figure, (b) are respectively shield shell structural front view and side view, (c) are shieldings Body cover plate side view, pectination sheet elastic reaction makes it keep the conduction close contact after cover plate and housing close, And easily dismounting. Each circuit unit shielding box body and the dark intercalation mode of its cover plate, i.e. box body and lid Highly close or equal, box body outer wall and lid inwall size be interference fits more closely.
The corner of shield shell is rounded to make its interfere with electromagnetic field be difficult for leaking, internal layer shield each circuit unit it Between the connection of signaling interface, adopt the lead of coaxial cable or overcoat metal tube ground connection, its internal layer has been shielded Whole intact, be strictly on guard against to disturb and leak.
The internal layer shielding box is established respectively by its circuit sequential working characteristics in each basic circuit unit of electric ballast Body reduces mutually unnecessary coupling, means that the machine line rational deployment has positive meaning.
Fig. 3 (a) is that half-bridge or full bridge power inverse switch pipe VT are provided with capacitance-resistance RC absorption spike potential circuit, transient absorption peaking voltage in switching tube conducting and shutoff, the RC effect of discharging and recharging obviously suppresses the generation of electromagnetic interference, and reduces the switching tube power consumption, reduces the device heating amount.Fig. 3 (b) is that capacitance-resistance RC absorbs the resistance of spike circuit and meets diode D, and its effect is that clamper is placed restrictions on the voltage that switching tube VT voltage is not more than capacitor C, and D made its resistive short when switching tube turn-offed, and improved the spike assimilation effect.Half-bridge mid point over the ground and the direct current supply contact over the ground between add decoupling filter network or decoupling capacitor, make switch conduction required big electric current of moment by the decoupling filter network electric capacity current source that affords redress, avoid causing bigger current fluctuation and producing electromagnetic noise, and suppress its pollution power supply at power supply and grounded circuit.
The power supply electromagnetic interface filter adopts multistage common mode, differential mode LC passive low ventilating filter to form, it is improved on common power supply electromagnetic interface filter basis, common mode, the passive low-pass filter network of differential mode LC just have the wideband stopband at least more than secondary, in other frequency detuning work except that power frequency sufficiently high insertion loss should be arranged.Common mode inductance two-wire and on a magnetic coil skeleton that does not add air gap, the inductance turn ratio is 1, two ends of the same name are unified for inputing or outputing, to power current is opposite sign but equal magnitude, can be unsaturated, and common mode disturbances is had stronger inhibition, its rejection coefficient and inductance value direct ratio, but unsuitable excessive, not so easily heating.Differential mode inductance is selected the coil rack coiling of E shape magnetic for use, magnetic leaves air gap to inserting, it is better than worker's shape magnetic that it suppresses the electromagnetic interference effect, common mode filtering electric capacity is by feedthrough capacitor and connect over the ground large bulk capacitance and make it disturb bypass effect remarkable, be suitable for using in the shielding construction that wideband disturb to suppress, metallic plate is set between the filters at different levels isolates, suppress parasitic couplings and strengthen filter action.
Specific implementation method
The embodiment of the invention 1; comprise metal-back 2; power supply electromagnetic interface filter 3; rectification circuit and APFC or passive power factor correcting circuit 5; high-frequency pulse oscillator and its half-bridge or full bridge power inverse switch and overload protecting circuit 7; metal shell 2 is made as the dual shield structure; by ballast housing is that outer shielding 2 and each circuit unit shielding box are internal layer shielding 3; 5; 7 constitute; outer shielded metal housing 2 is provided with elastic metallic pectination sheet 21 with cover plate 22 contact portions; internal layer shield shell 3; 5; 7 with the dark intercalation mode of cover plate; the housing 3 of outer shielding 2 and internal layer shielding; 5; 7 be seamless; the corner is rounded; outer shielding 2 and internal layer shielding 3; 5; 7 install the isolation that certain space is arranged each other; outer shielding 2 and internal layer shielding 3; 5; 7 only for some overlap joints; outer shielded metal housing 2 joins with the earth; ballast power input IN; the output OUT that connects fluorescent tube all uses feed-through capacitor 1; 8 penetrate in the metal shell 2; its electric capacity 1; 8 external electrodes closely are fixed on the metal shell; electric capacity 1; electrode is a binding post in 8, and internal layer shielding box signaling interface adopts the lead 4 of coaxial cable or overcoat metal tube ground connection; 6 connect.
This embodiment is an electronic ballast for fluoresent lamp; high-frequency pulse oscillator fundamental frequency 78kHz; MOSFET fet power pipe constitutes the semi-bridge inversion switch; and overload protecting circuit is set; ballast output power 58w * 2; at its switching tube and meet capacitance-resistance RC and absorb the spike potential circuit; and add decoupling capacitor at its inverse switch feeder ear; the power supply electromagnetic interface filter adopts two-stage common mode combinational circuit; full-wave bridge heap rectification and passive power factor correcting circuit; metal shell is made as the dual shield structure, the ballast power input; the output that connects fluorescent tube all penetrates the metal shell high frequency bypass through feedthrough capacitor.GB GB17743-99 " limit value and the method for measurement of the radio disturbance characteristic of electric lighting and similar devices " is adopted in the sold inside the country Electro Magnetic Compatibility EMC examination of product, IEC/CISPR15 " method of measurement and the limit of fluorescent lamp and lighting device radio disturbance characteristic " standard testing and German VDE authentication are adopted in the American-European international market of export trade, this embodiment frequency range at the conduction interference voltage of 9kHz～50MHz much smaller than 56dB μ v.
The embodiment of the invention 2, technical scheme is identical with embodiment 1, it is a power output 400w high-intensity discharge HID metal halogen lamp electric ballast, take to be with low frequency random noise and sawtooth wave composite frequency modulation high-frequency pulse oscillator (this technology is seen number of patent application 200510061155.7) in order to suppress high-intensity discharge lamp distinctive " acoustic resonance ", its centre frequency is 120kHz, MOSFET fet power pipe constitutes the semi-bridge inversion switch drive, and meet capacitance-resistance RC and absorb the spike potential circuit, and add decoupling capacitor at its inverse switch feeder ear, the power supply electromagnetic interface filter adopts two-stage common mode combinational circuit, full-wave bridge heap rectification and APFC APFC, metal shell is made as the dual shield structure, the ballast power input, the output that connects fluorescent tube penetrates the metal shell high frequency bypass with feedthrough capacitor.Electromagnetic compatibility EMC suppresses the examination of interference characteristic and adopts U.S. FCC part18 standard testing, and conducted interference frequency range 0.45～30MHz is all-round excellent in 48dB μ v limiting value.
The embodiment of the invention 3, technical scheme is identical with embodiment 1, power output 1000w high-pressure sodium lamp great-power electronic ballast, equally in order to suppress high-intensity discharge lamp distinctive " acoustic resonance " phenomenon, adopt composite frequency modulation of sine wave and noise high-frequency pulse oscillator (this technology is seen number of patent application 200510061156.1), its centre frequency is 98kHz, MOSFET fet power pipe constitutes the full-bridge inverting switch drive, at its switching tube and meet capacitance-resistance RC and absorb the resistance of spike potential circuit and connect diode, and add decoupling capacitor at its inverse switch feeder ear, the power supply electromagnetic interface filter adopts three grades of common mode combinational circuits, full-wave bridge heap rectification and APFC APFC, metal shell is made as the dual shield structure, the ballast power input, the output that connects fluorescent tube penetrates high frequency bypass in the metal shell by feedthrough capacitor.Electromagnetic compatibility EMC suppresses the examination of interference characteristic and adopts German VDE Valuation Standard test, and the frequency range of narrow band interference is at 10kHz～100kHz magnetic field＜10dB μ A/m, electric field＜66dB μ v/m; Frequency range in 0.1～1MHz magnetic field＜1dB μ A/m, electric field＜50dB μ v/m; Frequency range in 1～30MHz magnetic field＜0.1dB μ A/m, electric field＜30dB μ v/m.
The present invention suppresses electromagnetic interference to be from the ballast switching circuit and to connect that capacitance-resistance RC absorbs the spike circuit or at the resistance of capacitance-resistance RC circuit and connect diode and improve the source that absorbs spike voltage and set about, take tight dual shield structure, the ballast power input, connect the fluorescent tube output lead terminal electrocardio that all wears long and hold high frequency bypass, multistage power supply electromagnetic interface filter, multiple link aggregate measures such as shield ground connection, can not only suppress the strong electromagnetic that great-power electronic ballast produces, simultaneously can suppress outside strong electromagnetic well and enter electric ballast, thereby strengthen its job stability greatly.
High-performance Electro Magnetic Compatibility EMC of the present invention is fit to various electric ballast and satisfies the specification requirement that electromagnetic interference suppresses, comprise the inhibition of high-power high-intensity discharge lamp electronic ballast electromagnetic interference, its product can be used by the illumination in international authentication of EMC and the high request protection electromagnetic environment smoothly.
Claims (3)
1; a kind of dual shield suppresses the electric ballast of electromagnetic interference; comprise metal-back; the power supply electromagnetic interface filter; rectification circuit and APFC or passive power factor correcting circuit; high-frequency pulse oscillator and its half-bridge or full bridge power inverse switch and overload protecting circuit; it is characterized in that: metal shell is made as the dual shield structure; by the ballast metal shell is that outer shielding and each circuit unit shielding box are that the internal layer shielding constitutes; outer shielded metal housing and cover plate contact portion are provided with elastic metallic pectination sheet; the dark intercalation mode of internal layer shield shell and cover plate; outer shielding is seamless with the housing of internal layer shielding; the corner is rounded; outer shielding is installed the isolation that certain space is arranged each other with the internal layer shielding; outer shielding shields only for some overlap joints with internal layer; outer shielded metal housing and the earth join; the ballast power input; the output that connects fluorescent tube penetrates metal shell by feed-through capacitor; core electrode is a binding post in its electric capacity; the electric capacity external electrode is fastened on the metal shell, and internal layer shielding box signaling interface adopts the lead of coaxial cable or overcoat metal tube ground connection to connect.
2; dual shield according to claim 1 suppresses the electric ballast of electromagnetic interference; it is characterized in that: the power supply electromagnetic interface filter; rectification circuit and APFC or passive power factor correcting circuit; high-frequency pulse oscillator and half-bridge or full bridge power inverse switch and overload protecting circuit are provided with the internal layer shielding box respectively; its signaling interface adopts the lead of coaxial cable or overcoat metal tube ground connection to connect; half-bridge or full bridge power inverse switch also connect capacitance-resistance RC absorption spike potential circuit; or absorb the resistance of spike potential circuit and connect diode at RC, and half-bridge mid point over the ground and the direct current supply contact add decoupling filter network or decoupling capacitor between over the ground.
3, dual shield according to claim 1 suppresses the electric ballast of electromagnetic interference, it is characterized in that: the power supply electromagnetic interface filter adopts multistage common mode, differential mode LC passive low ventilating filter to form, common mode inductance two-wire and on the coil rack of a closed magnetic circuit magnetic, end of the same name is unified to be input or output, the differential mode inductance coil rack coiling of E shape magnetic, its magnetic leaves air gap to inserting, common mode filtering electric capacity is by the high frequency feedthrough capacitor and connect on over the ground the big capacity shunt capacitance, metallic plate is set between the filters at different levels isolates.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100499250A CN100521855C (en) | 2006-03-18 | 2006-03-18 | Electronic ballast of inhibiting electromagnetic interference through double shielding |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100499250A CN100521855C (en) | 2006-03-18 | 2006-03-18 | Electronic ballast of inhibiting electromagnetic interference through double shielding |
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| CN1822740A CN1822740A (en) | 2006-08-23 |
| CN100521855C true CN100521855C (en) | 2009-07-29 |
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| CNB2006100499250A Expired - Fee Related CN100521855C (en) | 2006-03-18 | 2006-03-18 | Electronic ballast of inhibiting electromagnetic interference through double shielding |
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Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101441976A (en) * | 2008-11-09 | 2009-05-27 | 宋裕福 | Wide-voltage starting electrodeless lamp capable of preventing electromagnetic radiation |
| CN102790522A (en) * | 2012-08-02 | 2012-11-21 | 西安华伟自控设备有限公司 | Realization method for high interference immunity power supply |
| CN106068679A (en) * | 2014-03-21 | 2016-11-02 | 罗伯特·博世有限公司 | By having the capacitance shield cover of damping network, switch mode power converters is carried out common mode noise rejection |
| CN107681884B (en) * | 2017-10-23 | 2021-03-23 | 北京新能源汽车股份有限公司 | Automobile air conditioner compressor and automobile |
| CN109246923A (en) * | 2018-10-09 | 2019-01-18 | 郑州云海信息技术有限公司 | A kind of pcb board and a kind of electronic equipment |
| CN110707902A (en) * | 2019-09-23 | 2020-01-17 | 清华大学 | Anti-interference circuit of power electronic transformer power module |
| CN113498283A (en) * | 2020-04-07 | 2021-10-12 | 南京南瑞继保电气有限公司 | Signal acquisition box for series compensation device |
| CN112014890A (en) * | 2020-08-28 | 2020-12-01 | 福建平潭旭坤实业有限公司 | Anti-electromagnetic interference device and method for radio wave perspective instrument receiver |
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2006
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