US3363168A - Ignition circuit for inverse-parallel connected ignitrons utilizing a single semiconductor controlled rectifier - Google Patents

Ignition circuit for inverse-parallel connected ignitrons utilizing a single semiconductor controlled rectifier Download PDF

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Publication number
US3363168A
US3363168A US393552A US39355264A US3363168A US 3363168 A US3363168 A US 3363168A US 393552 A US393552 A US 393552A US 39355264 A US39355264 A US 39355264A US 3363168 A US3363168 A US 3363168A
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United States
Prior art keywords
voltage
ignitrons
anode
winding
rectifier
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Expired - Lifetime
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US393552A
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English (en)
Inventor
Henri Jean Gerard Marie Daelen
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US Philips Corp
North American Philips Co Inc
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US Philips Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/04—Electrodes; Screens
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00—Resistance welding; Severing by resistance heating
    • B23K11/24—Electric supply or control circuits therefor
    • B23K11/248—Electric supplies using discharge tubes
    • 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
    • H02M1/02—Circuits specially adapted for the generation of grid-control or igniter-control voltages for discharge tubes incorporated in static converters

Definitions

  • a circuit for supplying power to a load includes two inverse-parallel connected ignitrons in series with a source of AC voltage and the load.
  • a first center-tapped winding is connected between the anodes of the ignitrons.
  • a second center-tapped winding is connected to the anodes and ignitors of the ignitrons by :means of a plurality of diodes.
  • a semiconductor controlled rectifier is connected between the center taps of the two windings and is pulsed to control the current fiow in the circuit. The circuit operates so that the full anode voltage is applied to the ignitors yet the maximum voltage produced across the controlled rectifier is at most equal to one half of the ignitron anode voltage.
  • the invention relates to a circuit arrangement for the alternate ignition of two anti-parallel connected ignitrons by means of a single controllable element.
  • controllable element is a switch contact conducting in both directions, for example, the contact of a relay.
  • the invention has for an object to provide a circuit arrangement in which this switch contact is replaced by the main current electrode circuit of a rectifying semiconductor switch, for example, a controllable semiconductor rectifier.
  • a rectifying semiconductor switch for example, a controllable semiconductor rectifier.
  • the invention provides a solution of this problem so that the full anode voltage can be applied to the ignition electrode of each ignitron, whilst the maximum voltage operative across the semiconductor switch is at most equal to one half of said anode voltage.
  • the circuit arrangement according to the invention is characterized in that the controllable element is a rectifying semiconductor switch, the main current electrode circuit of which is connected between the central tappings of the windings of two auto-transformers.
  • the central tapping of the winding which is connected to the anode of the semiconductor switch is connected between the anodes of the two ignitrons.
  • Each side of the other winding is connected to the anodes of two diodes, the cathodes of which are respectively connected to the anode and to the ignition electrode of one of the two ignitrons.
  • the rectifying semiconductor switch may be a power rectifier, for example, a p-n-p-n diode having a Well determined threshold voltage, in series with which a mechanical on-oif switch can be connected.
  • the arrangement according to the invention is, however, particularly suitable when a phase-control of the ignition is desired.
  • the rectifying semiconductor switch is then a controllable semiconductor rectifier.
  • the embodiment shown comprises two anti-parallel connected ignitrons 1 and 2, through which a load 3, for example, a welding transformer, is energized by an alternating-voltage source 4, for example, an A.C. supply of 50 c./s.
  • the circuit for igniting the ignitrons 1 and 2 includes a rectifying semiconductor switch 5, formed by a controllable n-p-n-p-type semiconductor rectifier, the main current electrode circuit of which is connected in series with a semiconductor diode 6, connected in the reverse direction, between the central tappings of the windings 7 and 8 of two autotransformers 9 and 10.
  • the anode of the controllable rectifier 5 is connected to the anode of the diode 6 and the cathode of said diode is connected to the central tapping of the winding 7.
  • Winding 7 is connected between the anodes of the two ignitrons 1 and 2..
  • the n-type emitter of the controllable rectifier 5 is connected to the central tapping of the other winding 8 and to a terminal of a source 11 of phase-controllable control-pulses having a repetition frequency of, for example, c./s.
  • the control-electrode of the controllable rectifier 5 is connected to the other terminal of said source so that positive control-pulses are applied to said control-electrode.
  • Each end of the other winding 8 is connected to the anodes of two diodes 12, 14 and 13, 15, respectively.
  • the cathodes of these diodes are respectively connected to the anode and to the ignition electrode of the associated ignitrons 1 and 2, respectively.
  • the ignitron 2 is still non-conducting, whereas the ignitron 1 is already extinguished because the passing current has become lower than its holding current.
  • the voltage of the source 4 is therefore operative across the series combination of the load 3 and the winding 7.
  • the impedance of said Winding is high as compared with that of the load 3, so that substantially the whole voltage of the source 4 is operative across the winding 7.
  • the voltage of the source 4 and the impedance of the load 3 the discharge between ignition electrode and cathode of the ignitron 2 is extinguished immediately after the ignition of the main discharge between its anode and cathode. It may, however, occur that the voltage which is still applied between ignition'electrode and cathode after the ignitron of the main discharge is not sufficiently reduced for ensuring the extinction of the ignition arc. A strong current then continues to fiow through the ignition electrode for the remainder of the half period concerned, so that this electrode finally burns down or is seriously damaged.
  • a current of equal value also continues to pass through the diode 12 and twice this current passes through the controllable semiconductor rectifier 5, so that particularly the latter element is soon overloaded. This is prevented by the diode 6, which extinguishes as soon as the voltage across the left-hand part of the winding 7 becomes smaller than its Zener break-down voltage of, for example, 12 v.
  • the controllable rectifier 5 is then immediately cut off and any further current supply to the ignition electrode of the i-gnitron 2 is interrupted.
  • the semiconductor diode 6 may be replaced by another element having a strongly voltage-dependent resistance and which only becomes highly conducting when the voltage across it exceeds one half of the anode-cathode arc voltage of each of the two ignitrons, for example, by a so-called voltage-dependent resistor (VDR).
  • VDR voltage-dependent resistor
  • a circulation current may, for example, continue to flow for the remainder of the half period concerned through the left-hand or right-hand halves of the windings 7 and 8, the diodes 12 or 13 and the controllable rectifier 5.
  • An i-gnitron ignition circuit comprising, a source of AC voltage, an electric load, first and second ignitrons each having an anode, cathode and ignitor electrode, means connecting said first and second ignitrons in inverse-parallel relationship in series with said voltage source and said load, first and second center-tapped transformer windings, means connecting said first transformer winding between the anodes of said ignitrons, first, second, third and fourth diodes, means connecting said first and second diodes between one side of said second transformer winding and the ignitor and anode of said first ignitron, respectively, means connecting said third and fourth diodes between the other side of said second transformer winding and the ignitor and anode of said second ignitron, respectively, a semiconductor rectifying element having first and second electrodes defining a current path therein and a control electrode for controlling the current in said path, means connecting said semiconductor element bet-ween the center taps of said first and second windings, and means for applying
  • a circuit as defined in claim 1 further comprising a zener diode having a zener threshold voltage that exceeds one half of the anode-cathode arc discharge voltage of the ignitrons, and means connecting said zener diode in series with the current path of said semiconductor rectifying element.
  • a circuit for coupling a source of AC voltage to an electric load comprising, first and second ignitrons each having an anode, cathode and ignitor electrode, means connecting said first and second ignitrons in inverseparallel relationship in series with said voltage source and said load, first and'second center-tapped transformer windings, means connecting said first transformer winding between the anodes of said ignitrons, first, second, third and fourth diodes, means connecting the anode electrodes of said first and second diodes to one end of said second winding and the cathode electrodes to said ignitor and anode electrodes, respectively, of said first ignitron, means connecting the anode electrodes of said third and fourth diodes to the other end of said second winding and the cathode electrodes to said ignitor and anode electrodes, respectively, of said second ignitron, a semiconductor rectifier element having anode, cathode and control electrodes, means connecting the anode and cathode
  • a circuit as defined in claim 6 further comprising a zener diode having a zener voltage that is greater than one half of the anode-cathode arc discharge voltage of said ignitrons, means connecting said zener diode in series With the anode and cathode of said semiconductor rectifier element between the center taps of said first and second Winding, and wherein said voltage applying means includes a source of voltage pulses having a frequency that is twice the frequency of said AC voltage.
  • a circuit as defined in claim 6 further comprising a voltage-dependent resistor connected in series with said rectifier element.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
  • Control Of Electrical Variables (AREA)
  • Generation Of Surge Voltage And Current (AREA)
US393552A 1963-09-17 1964-09-01 Ignition circuit for inverse-parallel connected ignitrons utilizing a single semiconductor controlled rectifier Expired - Lifetime US3363168A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL63298023A NL139680B (nl) 1963-09-17 1963-09-17 Inrichting voor het om de beurt ontsteken van twee antiparallel geschakelde ignitrons.

Publications (1)

Publication Number Publication Date
US3363168A true US3363168A (en) 1968-01-09

Family

ID=19755051

Family Applications (1)

Application Number Title Priority Date Filing Date
US393552A Expired - Lifetime US3363168A (en) 1963-09-17 1964-09-01 Ignition circuit for inverse-parallel connected ignitrons utilizing a single semiconductor controlled rectifier

Country Status (10)

Country Link
US (1) US3363168A (fr)
JP (1) JPS4327016B1 (fr)
AT (1) AT242241B (fr)
BE (1) BE653121A (fr)
CH (1) CH425947A (fr)
DE (1) DE1193990B (fr)
DK (1) DK117364B (fr)
FR (1) FR1409604A (fr)
GB (1) GB1031148A (fr)
NL (2) NL139680B (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL298023A (fr) * 1963-09-17

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1031148A (en) * 1963-09-17 1966-05-25 Philips Electronic Associated Improvements in and relating to circuit arrangements for the ignition of two cross-connected ignitrons

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1031148A (en) * 1963-09-17 1966-05-25 Philips Electronic Associated Improvements in and relating to circuit arrangements for the ignition of two cross-connected ignitrons

Also Published As

Publication number Publication date
CH425947A (de) 1966-12-15
FR1409604A (fr) 1965-08-27
DE1193990B (de) 1965-06-03
JPS4327016B1 (fr) 1968-11-20
NL298023A (fr)
NL139680B (nl) 1973-09-17
AT242241B (de) 1965-09-10
BE653121A (fr) 1965-03-15
DK117364B (da) 1970-04-20
GB1031148A (en) 1966-05-25

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