US3764883A - Monitoring apparatus for preventing spark-overs at a high voltage installation - Google Patents

Monitoring apparatus for preventing spark-overs at a high voltage installation Download PDF

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Publication number
US3764883A
US3764883A US00301149A US3764883DA US3764883A US 3764883 A US3764883 A US 3764883A US 00301149 A US00301149 A US 00301149A US 3764883D A US3764883D A US 3764883DA US 3764883 A US3764883 A US 3764883A
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US
United States
Prior art keywords
voltage
input
power amplifier
output
monitoring apparatus
Prior art date
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Expired - Lifetime
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US00301149A
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English (en)
Inventor
Staad F Braun
P Ribnitz
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Gema Switzerland GmbH
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Gema AG
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Assigned to RANSBURG-GEMA AG, A SWITZERLAND CORP reassignment RANSBURG-GEMA AG, A SWITZERLAND CORP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: GEMA AG APPARATEBAU, A CORP. OF SWITZERLAND
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/08—Plant for applying liquids or other fluent materials to objects
    • B05B5/10—Arrangements for supplying power, e.g. charging power
    • 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
    • H02H3/24—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 responsive to undervoltage or no-voltage
    • 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
    • H02H3/26—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 responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
    • H02H3/28—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 responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus
    • 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
    • H02H7/003—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 electrostatic apparatus

Definitions

  • a comparator has its inputs coupled with 250/324, 325, 326; 317/27 R, 31, 51; the input and output respectively of the power ampli- 330/51; 321/11 bomb and in the event the output voltage of the power amplifier is smaller than its input voltage interrupts [56] References Cited the current circuit to the corona electrode through the UNITED STATES PATENTS agency of a cutoff mechanism.
  • Prior art apparatuses for monitoring the high voltage at corona electrodes in equipment for spray painting or lacquering are only then generally effective when there has already occurred a spark-over owing, for instance, to the corona electrode and the object undergoing treatment approaching one another too closely.
  • a great prevalent danger is the possible explosion of the sprayed powder cloud.
  • attempts have been made to reduce to the greatest possible extent the energy of the sparkover by employing an alternating'current voltage of as high as possible frequency, so that the high voltage transformer and the capacitances at the high voltage cascade circuit arrangement can be selected to be small and thus store very little energy.
  • Other monitoring devices contemplate reducing the electrode voltage as soon as a spark-over condition arises.
  • Another and more specific object of the present invention relates to a new and improved construction of monitoring apparatus which is relatively simple in construction and design and which removes the voltage from the corona electrode before a sparkover condition arises.
  • the inventive monitoring apparatus of this development is manifested by the features that the high-frequency voltage source is connected via a power amplifier, which starting from a certain value of its output current exhibits current limiting and decreasing output voltage characteristics, with the primary winding of a high voltage transformer.
  • a comparator has its inputs connected with the input and output respectively of the power amplifier and in the event that the output voltage of the power amplifier is smaller than its input voltage the comparator, through the agency of a cutoff mechanism, interrupts the current circuit to the corona electrode.
  • FIG. 1 is a schematic circuit diagram of monitoring apparatus designed according to the teachings of this development wherein a portion of the circuit diagram is depicted in block configuration and another portion thereof depicted with its individual components;
  • FIG. 2 is a graph showing the dependency of the output voltage of the power transformer upon the output current with constant input voltage.
  • FIG. 1 there is illustrated an exemplary embodiment of the inventive monitoring apparatus embodying a high-frequency voltage source in the form of an oscillator 1 which generates an alternating-current voltage at a fequency of 17 kHz with a constant voltage of 12 volts.
  • the output of the oscillator 1 is electrically coupled with a first terminal 20 of a first potentiometer R,, the second terminal 21 of which is grounded.
  • the sliding tap 30 of potentiometer R is coupled through the agency of a rest contact a belonging to a relay A defining a cutoff mechanism with the input 22 of a known power amplifier 2 and with the anode 23 of a first diode D,.
  • This power amplifier 2 possesses a large current gain; its voltage gain normally amounts to approximately 1.
  • the output voltage U appearing at the amplifier output 24 corresponds to the input voltage U, when the output current la does not exceed a certain value.
  • the output current I exceeds the value la then the output voltage U, decreases approximately in linear fashion, as best seen by referring to FIG. 2, and amounts to zero at the time of maximum possible output current Ia" (short-circuit condition).
  • the output 24 of the amplifier 2 is coupled with the primary winding 25 of a high-voltage transformer 3 and with the anode 26 of a second diode D
  • the secondary winding 27 of the high-voltage transformer 3 is coupled with the input 28 of a high-voltage cascade circuit arrangement 4 which delivers a direct-current voltage of about kV to a corona electrode 5.
  • the second terminal 35 of the potentiometer R is connected to ground via a resistor R
  • the sliding tap 40 of the potentiometer R is connected to the non-inverting input 41, also designated by reference character with a comparator 6.
  • the cathode 29 of the second diode D is connected with the inverting input 42, also designated by reference character of the comparator 6 and a terminal 43 of a grounded capacitor C
  • the base 44 of a switching transistor T is coupled through the agency of a resistor R, with the output 45 of the comparator 6. At the collector current circuit of transistor T there is ar ranged the relay A.
  • the electrode current and accordingly also the current at the primary winding 25 of the high voltage transformer begins to rise.
  • the output voltage Ua begins to drop and therefore also the voltage U
  • the transistor T conducts, the relay A is actuated and the rest contact a opens, so that the current supply to the corona electrode 5 is interrupted.
  • the resistor R serves the purpose of preventing the voltage U from dropping to zero. If this should happen then the equipment will be erroneously completely disconnected so that even with a spark-over it will not respond.
  • a monitoring apparatus for preventing spark-overs at a high voltage installation for corona electrodes comprising a high-frequency voltage source, a corona electrode, a high-voltage transformer having a primary winding and a secondary winding, a high-voltage cascade arrangement connected in circuit with the corona electrode, the secondary winding of said high-voltage transformer being coupled with the corona electrode via said high-voltage cascade arrangement, a power amplifier means, which starting at a certain value of its output current exhibits current limiting and decreasing output voltage characteristics, said high-frequency voltage source being electrically coupled with the primary winding of the high-voltage transformer through the agency of said power amplifier means, comparator means having a first input, a second input and an output, said power amplifier means having an input and an output, one of the inputs of said comparator means being connected with the input of the power amplifier means and the other input of said comparator means being connected with the output of said power amplifier means, cutoff means for the corona electrode, said comparator means interrupting the
  • the high-frequency voltage source comprises oscillator means with adjustable output voltage.
  • said cutoff means comprises a relay which can be actuated by said comparator means, said relay having a switching contact arranged in circuit between the high-frequency voltage source and the power amplifier means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Electrostatic Spraying Apparatus (AREA)
  • Dc-Dc Converters (AREA)
  • Measurement Of Current Or Voltage (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
US00301149A 1971-10-28 1972-10-26 Monitoring apparatus for preventing spark-overs at a high voltage installation Expired - Lifetime US3764883A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1572571A CH532859A (de) 1971-10-28 1971-10-28 Uberwachungsvorrichtung zur Verhinderung von Funkenüberschlägen in einer Hochspannungsanlage für Sprühelektroden

Publications (1)

Publication Number Publication Date
US3764883A true US3764883A (en) 1973-10-09

Family

ID=4411411

Family Applications (1)

Application Number Title Priority Date Filing Date
US00301149A Expired - Lifetime US3764883A (en) 1971-10-28 1972-10-26 Monitoring apparatus for preventing spark-overs at a high voltage installation

Country Status (11)

Country Link
US (1) US3764883A (enrdf_load_stackoverflow)
JP (1) JPS4851218A (enrdf_load_stackoverflow)
BR (1) BR7207546D0 (enrdf_load_stackoverflow)
CA (1) CA960294A (enrdf_load_stackoverflow)
CH (1) CH532859A (enrdf_load_stackoverflow)
DE (1) DE2251568C3 (enrdf_load_stackoverflow)
ES (1) ES408056A1 (enrdf_load_stackoverflow)
FR (1) FR2158031B1 (enrdf_load_stackoverflow)
GB (1) GB1383065A (enrdf_load_stackoverflow)
IT (1) IT966770B (enrdf_load_stackoverflow)
SE (1) SE380940B (enrdf_load_stackoverflow)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3961193A (en) * 1975-05-27 1976-06-01 Xerox Corporation Self adjusting corona device
US4075677A (en) * 1976-08-09 1978-02-21 Ransburg Corporation Electrostatic coating system
US4150413A (en) * 1977-11-04 1979-04-17 Rohr Industries, Inc. Transistor overload inhibit
US4187527A (en) * 1976-08-09 1980-02-05 Ransburg Corporation Electrostatic coating system
US4320434A (en) * 1979-12-10 1982-03-16 General Electric Company Power semiconductor protection circuit with fault detection
US4331856A (en) * 1978-10-06 1982-05-25 Wellman Thermal Systems Corporation Control system and method of controlling ion nitriding apparatus
US4428020A (en) 1981-10-14 1984-01-24 Scm Corporation Power supply sensing circuitry
US4476373A (en) * 1978-10-06 1984-10-09 Wellman Thermal Systems Corporation Control system and method of controlling ion nitriding apparatus
US4663537A (en) * 1984-07-03 1987-05-05 Keiper Recaro Gmbh & Co. Protective circuit
US4737887A (en) * 1985-10-02 1988-04-12 Sames S.A. Electrostatic spray device provided with electric-arc protection means
US5400204A (en) * 1989-02-28 1995-03-21 Otis Elevator Company System for detecting a breakage of a power cable for an elevator system
US5566042A (en) * 1993-04-08 1996-10-15 Nordson Corporation Spray gun device with dynamic loadline manipulation power supply
US5939993A (en) * 1995-07-10 1999-08-17 Sames S.A. Method for developing a high voltage and device for electrostatic coating product spraying
US5978244A (en) * 1997-10-16 1999-11-02 Illinois Tool Works, Inc. Programmable logic control system for a HVDC power supply
US6144570A (en) * 1997-10-16 2000-11-07 Illinois Tool Works Inc. Control system for a HVDC power supply
US20050136733A1 (en) * 2003-12-22 2005-06-23 Gorrell Brian E. Remote high voltage splitter block
CN102665923A (zh) * 2009-10-09 2012-09-12 旭燦纳克株式会社 静电涂装系统、静电涂装喷枪及交流电源装置

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5513605A (en) * 1978-07-12 1980-01-30 Pioneer Electronic Corp Voltage control circuit for pulse width modulation power soruce
FR2532127A1 (fr) * 1982-08-18 1984-02-24 Skm Sa Dispositif generateur de haute tension pour appareil de projection electrostatique
FR2535917A1 (fr) * 1982-11-04 1984-05-11 Skm Sa Procede pour alimenter en haute tension continue un appareil de pulverisation electrostatique et dispositif pour la mise en oeuvre du procede
JPS59133570A (ja) * 1983-01-20 1984-07-31 Sharp Corp コロナ放電器の異常検出装置
DE102015215402A1 (de) 2015-08-12 2017-02-16 Gema Switzerland Gmbh Steuerschaltung zum Schutz gegen Funkenentladung

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2066522A (en) * 1934-12-19 1937-01-05 Bell Telephone Labor Inc Protective system and method
US3217207A (en) * 1961-05-26 1965-11-09 Elox Corp Michigan Peak drive protective circuit
US3449635A (en) * 1967-08-21 1969-06-10 Us Navy Transmitter overload protection circuit
US3657603A (en) * 1970-07-24 1972-04-18 William M Adams Relay control responsive to overvoltage and undervoltage
US3665253A (en) * 1970-12-02 1972-05-23 Gte Sylvania Inc Short circuit protection device for multiple power supplies

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2066522A (en) * 1934-12-19 1937-01-05 Bell Telephone Labor Inc Protective system and method
US3217207A (en) * 1961-05-26 1965-11-09 Elox Corp Michigan Peak drive protective circuit
US3449635A (en) * 1967-08-21 1969-06-10 Us Navy Transmitter overload protection circuit
US3657603A (en) * 1970-07-24 1972-04-18 William M Adams Relay control responsive to overvoltage and undervoltage
US3665253A (en) * 1970-12-02 1972-05-23 Gte Sylvania Inc Short circuit protection device for multiple power supplies

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3961193A (en) * 1975-05-27 1976-06-01 Xerox Corporation Self adjusting corona device
US4075677A (en) * 1976-08-09 1978-02-21 Ransburg Corporation Electrostatic coating system
US4187527A (en) * 1976-08-09 1980-02-05 Ransburg Corporation Electrostatic coating system
US4150413A (en) * 1977-11-04 1979-04-17 Rohr Industries, Inc. Transistor overload inhibit
US4331856A (en) * 1978-10-06 1982-05-25 Wellman Thermal Systems Corporation Control system and method of controlling ion nitriding apparatus
US4476373A (en) * 1978-10-06 1984-10-09 Wellman Thermal Systems Corporation Control system and method of controlling ion nitriding apparatus
US4320434A (en) * 1979-12-10 1982-03-16 General Electric Company Power semiconductor protection circuit with fault detection
US4428020A (en) 1981-10-14 1984-01-24 Scm Corporation Power supply sensing circuitry
US4663537A (en) * 1984-07-03 1987-05-05 Keiper Recaro Gmbh & Co. Protective circuit
US4737887A (en) * 1985-10-02 1988-04-12 Sames S.A. Electrostatic spray device provided with electric-arc protection means
US5400204A (en) * 1989-02-28 1995-03-21 Otis Elevator Company System for detecting a breakage of a power cable for an elevator system
US5566042A (en) * 1993-04-08 1996-10-15 Nordson Corporation Spray gun device with dynamic loadline manipulation power supply
US5939993A (en) * 1995-07-10 1999-08-17 Sames S.A. Method for developing a high voltage and device for electrostatic coating product spraying
US5978244A (en) * 1997-10-16 1999-11-02 Illinois Tool Works, Inc. Programmable logic control system for a HVDC power supply
US6144570A (en) * 1997-10-16 2000-11-07 Illinois Tool Works Inc. Control system for a HVDC power supply
US6423142B1 (en) 1997-10-16 2002-07-23 Illinois Tool Works Inc. Power supply control system
US6562137B2 (en) 1997-10-16 2003-05-13 Illinois Tool Works Inc Power supply control system
US20050136733A1 (en) * 2003-12-22 2005-06-23 Gorrell Brian E. Remote high voltage splitter block
CN102665923A (zh) * 2009-10-09 2012-09-12 旭燦纳克株式会社 静电涂装系统、静电涂装喷枪及交流电源装置
US9085001B2 (en) 2009-10-09 2015-07-21 Asahi Sunac Corporation Electrostatic coating system, spray gun for electrostatic coating, and alternating power source unit
CN102665923B (zh) * 2009-10-09 2015-07-22 旭燦纳克株式会社 静电涂装系统及静电涂装喷枪

Also Published As

Publication number Publication date
CH532859A (de) 1973-01-15
GB1383065A (en) 1975-02-05
ES408056A0 (es) 1975-11-16
IT966770B (it) 1974-02-20
FR2158031A1 (enrdf_load_stackoverflow) 1973-06-08
FR2158031B1 (enrdf_load_stackoverflow) 1978-07-21
JPS4851218A (enrdf_load_stackoverflow) 1973-07-18
BR7207546D0 (pt) 1974-08-15
SE380940B (sv) 1975-11-17
ES408056A1 (es) 1975-11-16
DE2251568B2 (de) 1977-11-17
DE2251568C3 (de) 1978-06-29
CA960294A (en) 1974-12-31
DE2251568A1 (de) 1973-05-03

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Legal Events

Date Code Title Description
AS Assignment

Owner name: RANSBURG-GEMA AG, KUNKLERSTRASSE 9, 9015 ST. GALLE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GEMA AG APPARATEBAU, A CORP. OF SWITZERLAND;REEL/FRAME:004052/0993

Effective date: 19820823