US3579029A - Monitoring circuit for a high-intensity glow discharge for metallurgical processes - Google Patents

Monitoring circuit for a high-intensity glow discharge for metallurgical processes Download PDF

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Publication number
US3579029A
US3579029A US677660A US3579029DA US3579029A US 3579029 A US3579029 A US 3579029A US 677660 A US677660 A US 677660A US 3579029D A US3579029D A US 3579029DA US 3579029 A US3579029 A US 3579029A
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United States
Prior art keywords
voltage
transistor
input
current
circuit
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US677660A
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English (en)
Inventor
Gelli Spescha
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Elektrophysikalische Anstalt Bernhard Berghaus
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Elektrophysikalische Anstalt Bernhard Berghaus
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32018—Glow discharge
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/36—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases using ionised gases, e.g. ionitriding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/34—Gas-filled discharge tubes operating with cathodic sputtering

Definitions

  • This object is commonly achieved by influencing the electrical supply circuit for the glow discharge, by way of example by brief reductions of the operating voltage or by incorporation of an impedance. Such influencing is performed by suita control means such as electronic circuits controlled by signals which may, by way of example, be given when the operating current of the glow discharge exceeds a certain rated value.
  • a control means such as electronic circuits controlled by signals which may, by way of example, be given when the operating current of the glow discharge exceeds a certain rated value.
  • the present invention eliminates these difficulties and relates to a method of monitoring the electrical behavior of a high-intensity glow discharge for metallurgical processes such as diffusion processes, cathode sputtering, hardening by nitriding and the like in order to influence the supply circuit by signal-controlled means. It is characterized by the fact that an unsafe area is defined by an adjustable sensor which can be influenced by the supply circuits below the desired rated curve for the operating point of the glow discharge in the voltage/current characteristic family, the said area also comprising the field of unstable discharges and the said sensor supplying a control signal for the said means when the operating point deviates from the rated curve to the extent that it lies within the unsafe area.
  • the invention further relates to a device for the performance of the said method.
  • This device is characterized by a sensor consisting of a PNP transistor circuit and a Schmitt trigger of a design known per se, by a series resistance in the supply circuit to which an input terminal of the Schmitt trigger and the collector of the transistor are connected via a barrier resistance, by a voltage divider parallel with the voltage source of which the tap is connected to the base of the transistor, and by a series resistance and a bias in the emitter circuit of the transistor, all being arranged in such a manner that the voltage of the resistance in the supply circuit which depends on the discharge current and a countervoltage depending on the collector current through the barrier resistance are applied to the trigger input terminals, the collector current being so adjusted by means of the partial voltage tapped at the voltage divider and the emitter bias that the response voltage at the trigger input terminals is exceeded only for values of the discharge current and the discharge voltage within the unsafe area of the I 4 voltage/current characteristic family of the glow discharge.
  • FIG. 1 is a diagram of the voltage/current characteristic family in the operation of an electrical glow discharge
  • FIG. 2 is a sensor circuit for the performance of the present method
  • FIG. 3 is a block-type diagram illustrating the invention as applied to a three-phase power source.
  • the process here disclosed relates to an adjustable safety area located directly below the effective characteristic of the glow discharge, cf. FIG. l.--
  • the current and voltage are continuously measured and the position of the operating point thus determined assessed. If the operating point falls within the predetermined unsafe area, a quick-acting switch responds, i.e. it triggers the contemplated protective measures 2 in the supply circuit.
  • the latter consist in the known manner in a short discontinuation of the supply voltage and, in the event of frequent repetitions of the disturbance, in complete disconnection of the voltage source.
  • Adjustment of the safety line is most commonly effected by two potentiometers. The first is designed to adjust the minimum burning voltage; the other, to adjust the gradient dUldI. These two adjustments should be adapted depending on the'type of gas, pressure, temperature and cathode surface of the discharge. Changes in the operating voltage require no adjustment of the quick-acting switch which is suitableeveri for extreme impulse operation of the glow discharge.
  • This quick-acting switch principle is also suitable for threephase current.
  • Three similar sensor circuits are employed, one for each phase, and the three outlets arranged in parallel.
  • the safety means are then triggered if a disturbance is detected in any one of the three phases.
  • the transformer neutral point is not connected and, respectively, the secondary side of the transformer is connected in delta circuit.
  • the three symmetrical cathodes are each connected to one phase. Current measurement in eachphase raises no problems.
  • Schematic FIG. 3 shows how the invention is adapted to a three-phase power source 1 and wherein each line of the three-phase current is connected to a complete sensing transistor and associated circuitry indicated by the blocks 20.
  • the circuitry within each block 20 is the same as that appearing within the dotted rectangle 20 of FIG. 2.
  • Measurement of the proper burning voltage is complex since the discharge is operative alternatively between the three cathodes. It has been found that the gas plasma is approximately at the most positive potential of the three cathodes. Accordingly, at least one of the electrodes is always cathodic and the voltage between it and the positive plasma is decisive for its discharge.
  • the metallic anode assuming approximately the potential of the plasma, has proved to be satisfactory to measure the voltage between each electrode and the anode.
  • the measuring arrangement of each phase is thus fomied by measuring the current of the phase involved and the voltage of the respective electrode against the anode, it being sufficient to record the negative values only. Disturbances occur mostly at the cathodically glowing electrodes and every disturbance is thus recorded since the discharge operates without o-lead so that any disturbing current must pass a measuring point.
  • FIG. 2 shows an example of a simple circuit with only one transistor in the actual sensing stage.
  • the reference numeral 1 designates the supply rectifier, 2 the discharge anode or glow chamber in which the glow discharge occurs.
  • the current in the glow discharge I causes a voltage drop across resistance 6. This voltage is applied, via the resistance 7, to the input side of a Schmitt trigger 4.
  • This Schmitt trigger of known design responds if its input voltage U, reaches a certain value and then produces a signal at output 5.
  • Applied to the discharge anode 2 is a voltage U, so that the portion aU, is supplied, via
  • the voltage all, applies a bias on the transistor base resulting in a current through the emitter and the collector of thetransistor which essentially depends on aU,,, U and the resistance 8.
  • the voltage drop in the resistance 7 caused by this current counteracts the voltage caused by current 1, and thus allows the Schmitt trigger 4 to respond only in the presence of an accordingly greater current I,,.
  • FIG. 1 designates the real characteristic of the glow discharge
  • 2 the safety line obtained by an arrangement as per FIG. 2
  • Means for monitoring the electrical behavior of a high-intensity glow discharge apparatus having an input circuit means, comprising: a PNP transistor and a Schmitt trigger, a first resistor in series in said input circuit, the input to said Schmitt trigger and the collector of said transistor being connected to one end of said first resistor through a second resistor; a voltage divider across said input circuit having a point therein connected to the base of said transistor; second circuit means including a source of bias voltage for applying a potential between the emitter and base of said transistor, said input circuit means and second circuit means cooperating to produce a signal in response to the voltage across said first resistor and a counter voltage dependent on the current through the collector of said transistor and said second resistor, said signal being applied to the trigger input, said voltage divider including means for varying said collector current whereby the response voltage at the trigger input is exceeded only for values of the discharge current and the discharge voltage within the range of values of the voltage-current characteristic family of the glow discharge.
  • said input circuit comprises a three-phase circuit there being a transistor connected to each leg of said three-phase circuit in the manner described; there being a single Schmitt trigger connected to all said transistors whereby the input to said trigger is the algebraic sum of the phase voltages and the three counter voltages.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Analytical Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
US677660A 1966-11-08 1967-10-24 Monitoring circuit for a high-intensity glow discharge for metallurgical processes Expired - Lifetime US3579029A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEJ32190A DE1275228B (de) 1966-11-08 1966-11-08 Verfahren zur UEberwachung des elektrischen Verhaltens einer stromstarken Glimmentladung fuer metallurgische Verfahren und Einrichtung dazu

Publications (1)

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US3579029A true US3579029A (en) 1971-05-18

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US677660A Expired - Lifetime US3579029A (en) 1966-11-08 1967-10-24 Monitoring circuit for a high-intensity glow discharge for metallurgical processes

Country Status (8)

Country Link
US (1) US3579029A (no)
AT (1) AT284990B (no)
BE (1) BE705442A (no)
CH (1) CH499825A (no)
DE (1) DE1275228B (no)
GB (1) GB1202748A (no)
LU (1) LU54687A1 (no)
NL (1) NL153410B (no)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3914575A (en) * 1973-02-19 1975-10-21 Elektophysikalische Anstalt Be Power supplying device for the operation of a gas discharge container
US4130762A (en) * 1976-02-18 1978-12-19 Kloeckner Ionon Gmbh Arrangement for the automatic heating and adjustment of a treatment temperature for the treatment of workpieces by means of glow discharge
US4142957A (en) * 1976-02-18 1979-03-06 Klockner Ionon Gmbh Method and arrangement for heating workpieces to desired temperatures
FR2497038A1 (fr) * 1980-12-19 1982-06-25 Frager Jean Generateur de courant asservi en puissance, notamment pour processus de decharge dans une atmosphere rarefiee
US4476373A (en) * 1978-10-06 1984-10-09 Wellman Thermal Systems Corporation Control system and method of controlling ion nitriding apparatus
US4810936A (en) * 1986-12-01 1989-03-07 Hubbell Incorporated Failing lamp monitoring and deactivating circuit
US6660956B1 (en) * 2000-06-13 2003-12-09 Asm Technology Singapore Pte Method of and apparatus for monitoring a ball forming process

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2606395C3 (de) * 1976-02-18 1979-01-18 Ionit Anstalt Bernhard Berghaus, Vaduz Verfahren und Vorrichtung zur Überwachung des elektrischen Verhaltens einer stromstarken Glimmentladung
DE29520685U1 (de) * 1995-12-29 1997-04-24 Strämke, Siegfried, Dr.-Ing., 52538 Selfkant Schaltungsanordnung zum Betrieb einer Glimmentladungsstrecke
DE102014213744A1 (de) * 2014-07-15 2016-01-21 Primetals Technologies Germany Gmbh Elektrischer Lichtbogenofen mit einer Sicherheitsvorrichtung und Verfahren zur Sicherung von Peripheriegeräten an elektrischen Lichtbogenöfen

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2955237A (en) * 1956-07-13 1960-10-04 Telephone Mfg Co Ltd Fault indicating circuits
US3017564A (en) * 1954-08-12 1962-01-16 Barney Walter Protective circuit
US3300689A (en) * 1962-12-21 1967-01-24 Westinghouse Canada Ltd Voltage sensing circuit
US3303412A (en) * 1964-01-30 1967-02-07 Forbro Design Corp Current regulated power supply with compensating means for extraneous shunting current paths across the load
US3339111A (en) * 1965-05-20 1967-08-29 Jr Albert W Possner Redundant triggering circuit for a crowbar arc discharge switch
US3355626A (en) * 1964-04-11 1967-11-28 Philips Corp Circuit arrangement for the triggered discharge of a capacitor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE569245A (no) * 1953-12-09
AT219733B (de) * 1954-11-06 1962-02-12 Berghaus Elektrophysik Anst Einrichtung zur Durchführung von Prozessen mittels elektrischer Glimmentladungen

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3017564A (en) * 1954-08-12 1962-01-16 Barney Walter Protective circuit
US2955237A (en) * 1956-07-13 1960-10-04 Telephone Mfg Co Ltd Fault indicating circuits
US3300689A (en) * 1962-12-21 1967-01-24 Westinghouse Canada Ltd Voltage sensing circuit
US3303412A (en) * 1964-01-30 1967-02-07 Forbro Design Corp Current regulated power supply with compensating means for extraneous shunting current paths across the load
US3355626A (en) * 1964-04-11 1967-11-28 Philips Corp Circuit arrangement for the triggered discharge of a capacitor
US3339111A (en) * 1965-05-20 1967-08-29 Jr Albert W Possner Redundant triggering circuit for a crowbar arc discharge switch

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
INDUSTRIAL ELECTRONICS AND CONTROLS, by Royce Gerald (John Wiley & Sons, New York), 2nd Edition, 1960 pages: Title Page, Page IV, Page 176; page 224. *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3914575A (en) * 1973-02-19 1975-10-21 Elektophysikalische Anstalt Be Power supplying device for the operation of a gas discharge container
US4130762A (en) * 1976-02-18 1978-12-19 Kloeckner Ionon Gmbh Arrangement for the automatic heating and adjustment of a treatment temperature for the treatment of workpieces by means of glow discharge
US4142957A (en) * 1976-02-18 1979-03-06 Klockner Ionon Gmbh Method and arrangement for heating workpieces to desired temperatures
US4476373A (en) * 1978-10-06 1984-10-09 Wellman Thermal Systems Corporation Control system and method of controlling ion nitriding apparatus
FR2497038A1 (fr) * 1980-12-19 1982-06-25 Frager Jean Generateur de courant asservi en puissance, notamment pour processus de decharge dans une atmosphere rarefiee
DE3151241A1 (de) * 1980-12-19 1982-08-05 Frager Jean Leistungsgesteuerter stromgenerator
US4810936A (en) * 1986-12-01 1989-03-07 Hubbell Incorporated Failing lamp monitoring and deactivating circuit
US6660956B1 (en) * 2000-06-13 2003-12-09 Asm Technology Singapore Pte Method of and apparatus for monitoring a ball forming process

Also Published As

Publication number Publication date
LU54687A1 (no) 1968-01-26
CH499825A (de) 1970-11-30
DE1275228B (de) 1968-08-14
GB1202748A (en) 1970-08-19
BE705442A (no) 1968-03-01
NL6715084A (no) 1968-05-09
NL153410B (nl) 1977-05-16
AT284990B (de) 1970-10-12

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