Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
  • H02J9/02—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which an auxiliary distribution system and its associated lamps are brought into service
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
  • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
• • 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
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/14—Circuit arrangements
  • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC
  • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters
  • H05B41/282—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters with semiconductor devices
  • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
• • 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
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/14—Circuit arrangements
  • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC
  • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters
  • H05B41/282—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters with semiconductor devices
  • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
  • H05B41/2851—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
  • H05B41/2853—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions against abnormal power supply conditions
• • 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
  • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
  • H05B41/14—Circuit arrangements
  • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC
  • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters
  • H05B41/282—Circuit arrangements in which the lamp is fed by power derived from DC by means of a converter, e.g. by high-voltage DC using static converters with semiconductor devices
  • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
  • H05B41/2851—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
  • H05B41/2856—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions against internal abnormal circuit conditions
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
  • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
  • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
  • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
  • H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters

Definitions

• the present invention relates to the general subjects of power supplies and circuits for powering gas discharge lamps. More particularly, the present invention relates to a power supply and electronic ballast that includes an auxiliary protection circuit for the protecting the power supply or ballast against certain AC line fault conditions and for limiting the peak inrush current following initial application of AC power to the power supply or ballast.
• AC line drop-out conditions wherein the voltage provided by the AC source temporarily decreases to a level that is dramatically less than its nominal value
• DC-to-DC converter e.g., a boost converter
• an AC line drop-out condition (also referred to as a "line sag" condition) sometimes causes the DC-to-DC converter to enter into a "lock-out” mode wherein the converter fails to operate in a normal manner even after the AC line drop-out condition ceases; in such a case, it is necessary to cycle the AC input power to the ballast or power supply in order to allows the DC-to-DC converter to operate in its intended normal manner.
• an AC line dropout condition often causes a significant overshoot in the voltage provided at the output of the DC-to-DC converter, thereby endangering the reliability of the DC-to-DC converter.
• a common wiring error involves incorrectly connecting the input wires of the power supply or ballast to two different phases of the AC voltage source (instead of correctly connecting the "hot” wire to one phase and the "neutral” wire to the neutral connection of the AC voltage source).
• Such miswiring which is sometimes referred to as a "phase-to-phase” wiring fault condition, may produce voltages within the power supply or ballast that are significantly higher than normal, and which may therefore cause failure of certain components within the power supply or ballast.
• Inrush current which occurs upon initial application of AC power, is widely acknowledged to be a significant problem in power supplies and electronic ballasts, and is inherent (in the absence of protective/compensatory means) in many AC-line powered circuits which include a large bulk capacitance that is operably coupled in series with the AC voltage source. High peak inrush currents have been associated with a host of problems, including nuisance tripping of circuit breakers, degradation of electrical components, etc.
• FIG. 1 is an electrical diagram of an arrangement that includes an auxiliary protection circuit, in accordance with a preferred embodiment of the present invention. Detailed Description of the Preferred Embodiments
• FIG. 1 describes an arrangement 10 comprising a front-end circuit 100, a back-end circuit 200, and an auxiliary protection circuit 300.
• Front-end circuit 100 which typically includes an electromagnetic interference (EMI) filter and rectifier circuitry, includes first and second input connections 12,14 for receiving a conventional source of alternating current (AC) voltage 20 (e.g., 277 volts rms at 60 hertz).
• AC voltage source 20 provides a voltage VAC between first and second input connections 12,14.
• Back-end circuit 200 which typically includes power factor correction (e.g., boost converter) and inverter circuitry, is operably (i.e., not necessarily directly) coupled to front-end circuit 100.
• power factor correction e.g., boost converter
• inverter circuitry is operably (i.e., not necessarily directly) coupled to front-end circuit 100.
• back-end circuit 200 delivers power to a load 30 by way of first and second output connections 16,18.
• Auxiliary protection circuit 300 is coupled between front-end circuit 100 and back-end circuit 200.
• auxiliary protection circuit provides the following functions:
• phase-to-phase miswiring condition i.e., wherein first input connection 12 is connected to a first
• phase of AC source 20 and second input connection 14 is connected to a second phase of AC
• auxiliary protection circuit 300 includes first and second input terminals 302,304, first and second output terminals 306,308, first, second, third, fourth, and fifth nodes 310,312,314,316,318, first, second, third, and fourth electronic switches M1,M2,M3,M4, first, second third, fourth, fifth, sixth, seventh, and eighth resistors R1,R2,R3,R4,R5,R6,R7,R8, and first and second capacitors C1,C2.
• First and second input terminals 302,304 are coupled to front-end circuit 100.
• First and second output terminals 306,308 are coupled to back-end circuit 200.
• First electronic switch Ml is operably coupled between second input terminal 304 and second output terminal 308;
• first electronic switch Ml has a control terminal 332 coupled to first node 310.
• Second electronic switch M2 is operably coupled between first node 310 and circuit ground 320 (circuit ground 320 is coupled to second input terminal 304);
• second electronic switch M2 has a control terminal 342 coupled to fifth node 318. In response to a line-sag condition, M2 turns on and thereby turns off Ml.
• Third electronic switch M3 is operably coupled between second node 312 and circuit ground 320; third electronic switch M3 has a control terminal 352 coupled to fourth node 316. In response to a line-sag condition, M3 turns off and thereby allows M2 to turn on (which, in turn, causes Ml to turn off).
• Fourth electronic switch M4 is operably coupled between first node 310 and circuit ground 320; fourth electronic switch M4 has a control terminal 362 coupled to third node 314. In response to a phase-to-phase miswiring condition, M4 turns on and thereby turns off Ml.
• each of electronic switches M1,M2,M3,M4 is preferably realized by a N-channel field-effect transistor (FET).
• first electronic switch Ml has a gate terminal (i.e., control terminal) 332 coupled to first node 310, a drain terminal 334 coupled to second output terminal 308, and a source terminal 336 coupled to second input terminal 304.
• Second electronic switch M2 has a gate terminal (i.e., control terminal) 342 coupled to fifth node 318, a drain terminal 344 coupled to first node 310, and a source terminal 346 coupled to circuit ground 320.
• Third electronic switch M3 has a gate terminal (i.e., control terminal) 352 coupled to fourth node 316, a drain terminal 354 coupled to fifth node 318, and a source terminal 356 coupled to circuit ground 320.
• fourth electronic switch M4 has a gate terminal (i.e., control terminal) 362 coupled to third node 314, a drain terminal 364 coupled to first node 310, and a source terminal 366 coupled to circuit ground 320.
• first resistor Rl is coupled between first input terminal 302 and first node 310.
• Second resistor R2 is coupled between first node 310 and circuit ground 320.
• First capacitor Cl is coupled between first node 310 and circuit ground 320.
• Third resistor R3 is coupled between first input terminal 302 and second node 312.
• Fourth resistor R4 is coupled between second node 312 and third node 314.
• Second capacitor C2 is coupled between second node 312 and circuit ground 320.
• Fifth resistor R5 is coupled between third node 314 and circuit ground 320.
• Sixth resistor R6 is coupled between second node 312 and fourth node 316.
• Seventh resistor R7 is coupled between fourth node 316 and circuit ground 320.
• eigth resistor R8 is coupled between second node 312 and fifth node 318.
• M4 will turn on well before Ml has a chance to turn on.
• the voltage Va at node 310 will be pulled down to about zero (because when M4 is turned on, node 310 is effectively connected to circuit ground 320), thereby ensuring that Ml is not turned on.
• back-end circuit 200 is protected from any excessive (and potentially destructive) voltage that would otherwise (i.e., in the absence of auxiliary protection circuit 300) appear across output terminals 306,308 following a phase-to-phase miswiring condition.
• M4 will remain on (and, correspondingly, Ml will remain off) until at least such time as the excessive voltage (present across input terminals 302,304) due to the phase-to-phase miswiring condition is cured.
• Resistors R3,R6,R7 are sized so that, under this condition, the voltage Vd at node 316 will fall below the turn-on threshold necessary for keeping M3 on. Accordingly, M3 will be turned off. With M3 turned off, the voltage Ve at node 318 is allowed to assume a level (which, with M3 turned on, was at about zero volts) that exceeds the turn-on threshold of M2. Accordingly, M2 will turn on.
• M2 will remain on (and, correspondingly, Ml will remain off) until at least such time as the line-sag condition is cured and the voltage across input terminals 302,304 returns to an approximately normal level (at which point the voltage Vd will be higher than the turn-on threshold for M3, causing M3 to turn on, which cause Ve to go to about zero, thereby turning M2 off and allowing Ml to turn on).
• FET Ml Shortly after initial application of AC power to arrangement 10, FET Ml becomes conductive (i.e., once the voltage Va at node 310 reaches the turn-on threshold for Ml). It has been observed, in a prototype arrangement configured substantially as described in FIG. 1 , that, with the presence of auxiliary protection circuit 300, the peak inrush current (flowing into first input connection 12) was reduced from over 50 amperes (without auxiliary protection circuit 300) to a value on the order of only several amperes (with auxiliary protection circuit). Thus, auxiliary protection circuit 300 provides the added benefit of substantially reducing the peak inrush current.
• Arrangement 10 may be advantageously employed within any of a number of power supply circuits or within electronic ballasts for gas discharge lamps (for the latter application, load 30 will consist of one or more gas discharge lamps).

Landscapes

• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Electronic Switches (AREA)
• Inverter Devices (AREA)
• Circuit Arrangements For Discharge Lamps (AREA)
• Emergency Protection Circuit Devices (AREA)
• Rectifiers (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=39230744

Family Applications (1)

Country Status (4)

Families Citing this family (6)

Family Cites Families (11)

• 2007
  • 2007-09-07 EP EP07837873A patent/EP2067235A4/de not_active Withdrawn
  • 2007-09-07 KR KR1020097008849A patent/KR20090096689A/ko not_active Withdrawn
  • 2007-09-07 CN CN2007800361493A patent/CN101523679B/zh not_active Expired - Fee Related
  • 2007-09-07 WO PCT/US2007/019519 patent/WO2008039293A2/en not_active Ceased

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