US2809296A - Switching system - Google Patents

Switching system Download PDF

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Publication number
US2809296A
US2809296A US367947A US36794753A US2809296A US 2809296 A US2809296 A US 2809296A US 367947 A US367947 A US 367947A US 36794753 A US36794753 A US 36794753A US 2809296 A US2809296 A US 2809296A
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US
United States
Prior art keywords
switch
circuit
drop
current
tube
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US367947A
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English (en)
Inventor
Jr Robert Godbarsen
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General Electric Co
Original Assignee
General Electric Co
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Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Priority to US367947A priority Critical patent/US2809296A/en
Application granted granted Critical
Publication of US2809296A publication Critical patent/US2809296A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J47/00—Tubes for determining the presence, intensity, density or energy of radiation or particles
    • H01J47/12—Neutron detector tubes, e.g. BF3 tubes
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/38—Exposure time
    • H05G1/42—Exposure time using arrangements for switching when a predetermined dose of radiation has been applied, e.g. in which the switching instant is determined by measuring the electrical energy supplied to the tube
    • H05G1/44—Exposure time using arrangements for switching when a predetermined dose of radiation has been applied, e.g. in which the switching instant is determined by measuring the electrical energy supplied to the tube in which the switching instant is determined by measuring the amount of radiation directly

Definitions

  • This invention relates generally to improvements in electrical switching and more particularly to a high speed switching system adapted for the control of an energizing circuit for X-ray or other equipment.
  • An important object is to provide an improved switching circuit for initiating operation of an X-ray tube or other device operable from an A. C. supply line in synchronized relation to current and voltage waves in the supply line.
  • a more specific object is to provide an improved switching system for the control of X-ray apparatus of the type including interval measuring means for timing exposure intervals.
  • Figure 1 illustrates diagrammatically a switching circuit adapted for the control of X-ray equipment and embodying the invention.
  • Figure 3 shows a modification of a portion of the circuit of Figure 1.
  • Figure 4 illustrates graphically the operation of the circuit of Figure 1.
  • a sensing device 38 which may change impedance in response to the magnitude of detected X-radiation is in circuit with an interval measuring system 40 of known type which feeds an output signal to fire thyratron 1-2 in response to an amount of X-radiation to which detector 38 is exposed.
  • the sub-circuit shown in the upper right hand portion of the drawing is a phase shiftable D. C. bias suppiy and below it is shown a rectified source or voltage to provide D. C. anode potential for the triode 61 and thyratron 66, plus triggered actuating potential for electric-magnetic switch 30.
  • the other major components of the circuit consist of a plural contactor electromechanical switch 51 (to the right of system 49), operable from the position shown with contactors 5'3, 54, 55 and 56 open and contactor 57 closed, to a reversed position upon closure of switch 58 and resulting excitation of coil $2.
  • a second electro-rnechanical switch 41 is D. C.
  • the third electro-mechanical switch 39 includes, in addition to contactors 32, abovementioned, a coil 31 actuated by D. C. through the triggering of a triode 61, as later described.
  • the ultimate purpose of the invention is to apply a D. C. signal to coil 31 of switch 3% timed in respect to supply line current fluctuation to eifect closure of contactors 32 and the resulting application of anode potential to X-ray tube at or near zero line current, thus reducing transients and increasing timing accuracy.
  • the circuit operation will hereafter refer only to fluctuations in line current. it will be apparent to persons familiar with power factor considerations that the circuit may be synchronized for an optimum line condition mathematically obtained from the relation of current to voltage waves, but not coincident with either.
  • the circuit is compensated for drop-out lag of both switches 30 and 41 as later explained.
  • Coil 31 of switch 3d receives its D. C.
  • the firing of thyratron 66 is accomplished in novel manner later described in detail, but can only fire at certain phase positions in respect to supply line voltage fluctuations.
  • rectifier 60 operates to establish steady D. C. across capacitor 86, but that D. C. is isolated from the anodes of triode s1 and thyratron 66 by open contactors 54 and 55,
  • Triode 61 has been thus far cut-off, since the cathode and the grid are at the same potential, but it is rendered conductive in the following manner.
  • condenser 89 dissipates its charge exponentially through resistor 81, it approaches the firing point of tube 66 as shown in Fig. 4, however the negative going pulses V1 impressed across resistor 82 by the bias rectifier in effect prevent grid 70 from reaching the cut-off point except at positions near the base of the successive negative going pulses, since both the rectified signal and the charge from condenser 80 are impressed on grid 70 through resistor 83, as shown in heavy lines, Fig. 4.
  • the circuit may readily be adjustable to effect the firing of tube 6-6 at any point through 0-180" phase displacement in respect to line voltage and it is this basic concept which governs the actuation of switch 30 to switch on the X-ray tube ill at a desired point of zero or near zero line current.
  • thyratron 66 establishes current flow in resistor 67 which serves as a load resistor for tube 56.
  • the resulting voltage drop across 67 is employed to trigger triode 61, its cathode being connected to the negative end and its grid to the positive end of resistor 67 to swing the grid sufficiently positive to render tube 61 fully conductive.
  • the resulting D. C. current flow through tube 61 is applied to coil 31 through closed contactors 54 to switch on tube 11 at a point phase locked in respect to the line current wave to complete operation of that portion of the circuit.
  • the magnetic field status of coil 31 is improved by the application of D. C. to effect a more uniform pickup time than is possible with A. C., thus insuring phase locking of the contacts and consequent circuit closure.
  • tube 11 would operate for a period of time after the firing of thyratron 42, and since the extent of that interval, if left to chance, would not be accurately determinable, the total operating time of X-ray tube 11 or any function of that operating time such as detected X-ray quanta would be the sum of an accurate indication from system 40 plus the drop-out interval.
  • the drop-out interval may equal a substantial portion of the exposure interval.
  • the circuit provides for an adjustable total drop-out interval which includes cumulatively the drop-out intervals of switches 41 and 30 plus the bias controlled cut off time of triode 61, in the following manner.
  • Capacitor 64 is of a pre-selected value and charges upon firing of tube 66 and the establishment of a voltage drop across resistor 67. Opening of contactors 48 with the firing of tube removes the positive grid bias from tube 61 by opening the circuit to resistor 67, but sufiicient charge has been stored in capacitor 64 to hold tube at conducting until that charge leaks off to the cut-off point through adjustable resistor'dS, resulting in the opening of switch 30.
  • the drop-out intervals of electromagnetic switches 3t and 41 give a total drop-out interval of less than one-half cycle of line current fluctuation.
  • the time constant of capacitor s4 and resistor 65 is adjusted to a value that when added to the drop-out intervals of switches 41 and 30 insure a total drop-out interval equal to one-half cycle of current wave.
  • Drop-out intervals equal to one-half cycle or a multiple thereof are employed because the radiation resulting from a half cycle of operation is a constant for any given exposure condition hence the interval timer may include an anticipator circuit taking this constant into consideration to measure total exposure.
  • any desired multiple of this total drop-out time may be selected to compensate for longer switch dropout intervals, the important point being that the device, such as X-ray tube llll, is cut-ofi at a iiI'lOWll time interval after system 40 performs its function, hence the actual operating time of the device is obtainable from the sum of two accurately measured intervals.
  • Fig. 3 shows alternate circuitry for actuation of switch 41 in response to the firing of thyratron 42.
  • Contactors 53 are open, as in Fig. l, but when closed by switch 58 coil 47 is energized through fixed and adjustable resistors 88 and 89 respectively to close contactors 4-8
  • source 46 is shorted to ground through load resistor 87 with D. C. energization time of coil 47 controlled by series resistors 88 and 89. Since the drop-out constant of switch 41 is controllable by resistor 89, permitting adjustment of total drop-out time for the circuit, a variable is not required in the grid circuit of tube 61, hence that tube can be operated at a shorter cutoff time constant.
  • an alternating current work device a triggerable switch for the control of said device, means for triggering said switch including phase shifting means, a sourceof alternating current common to both said device and phase shifting means, and circuit means cooperatively associated with said triggering means, said phase shifting means, and said switch, whereby to effect actuation of said triggering means and resulting actuation of said switch only at or near a zero point in the current Wave of said source.
  • the circuit of claim 3 including time delay means operable in response to the triggering of said second switch to actuate said first switch at a predetermined time interval after the triggering of said first mentioned triggerable means.
  • a switch for energizing said device means for the timed termination of an energizing period, a second switch responsive to the actuation of said timing means for disconnecting said source, said switches having inherent dropout delay characteristics, and a time delay circuit associated with said second switch to add an interval, which, together with the drop-out intervals of both switches, equals a half cycle of line current or a multiple thereof.
  • the subcombination including a thyratron adapted to be fired at the end of a timed interval, an electro-magnetic switch including a coil, and a circuit for actuation of said switch in response to said firing, said circuit including a variable resistance series connected to one end of said coil and to the thyratron anode, a D. C.
US367947A 1953-07-14 1953-07-14 Switching system Expired - Lifetime US2809296A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US367947A US2809296A (en) 1953-07-14 1953-07-14 Switching system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US367937A US2909666A (en) 1953-07-14 1953-07-14 Interval timing apparatus and method
US367947A US2809296A (en) 1953-07-14 1953-07-14 Switching system

Publications (1)

Publication Number Publication Date
US2809296A true US2809296A (en) 1957-10-08

Family

ID=23449228

Family Applications (2)

Application Number Title Priority Date Filing Date
US367937A Expired - Lifetime US2909666A (en) 1953-07-14 1953-07-14 Interval timing apparatus and method
US367947A Expired - Lifetime US2809296A (en) 1953-07-14 1953-07-14 Switching system

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US367937A Expired - Lifetime US2909666A (en) 1953-07-14 1953-07-14 Interval timing apparatus and method

Country Status (6)

Country Link
US (2) US2909666A (nl)
JP (2) JPS325672B1 (nl)
DE (2) DE1110769B (nl)
FR (2) FR1167459A (nl)
GB (2) GB752971A (nl)
NL (1) NL105205C (nl)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2958782A (en) * 1958-01-13 1960-11-01 Gen Electric Electronic timer
US2993145A (en) * 1958-04-30 1961-07-18 Bell Telephone Labor Inc Switching apparatus
US3046451A (en) * 1958-10-01 1962-07-24 Westinghouse Electric Corp Switching circuit
US3094618A (en) * 1961-05-23 1963-06-18 Picker X Ray Corp X-ray tube protection mechanism
US3119932A (en) * 1960-02-12 1964-01-28 Philips Corp Polyphase current switching device for an x-ray tube supply circuit
US3440422A (en) * 1965-06-24 1969-04-22 Picker Corp Biplane x-ray image system

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3152255A (en) * 1959-07-24 1964-10-06 Philips Corp Device for measuring the X-ray radiations absorbed by a specimen
US3557371A (en) * 1968-06-10 1971-01-19 Scope Corp X Method and apparatus for calibrating a cardiac x-ray synchronizer
US3573461A (en) * 1969-04-01 1971-04-06 Stig Arne Ohlsson Method and apparatus for timing exposures in x-ray photography

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2003992A (en) * 1934-06-08 1935-06-04 Gen Electric Time delay circuit controlling apparatus
US2150440A (en) * 1936-06-10 1939-03-14 Western Union Telegraph Co Magnetic and resonator selector for carrier conveyers
US2165048A (en) * 1937-08-26 1939-07-04 Westinghouse Electric & Mfg Co Electric discharge apparatus
US2282182A (en) * 1939-09-07 1942-05-05 Westinghouse Electric & Mfg Co Amplifier circuit
US2361172A (en) * 1940-07-31 1944-10-24 Westinghouse Electric & Mfg Co Electronic power factor relay overload protection
US2401289A (en) * 1943-07-22 1946-05-28 Nasa Photoelectric timer for roentgen photography
US2413020A (en) * 1943-05-19 1946-12-24 Photoswitch Inc Electronic relay
US2422020A (en) * 1945-03-27 1947-06-10 Gen Electric Electric control circuit
US2473922A (en) * 1949-06-21 Breathing indicator
US2573029A (en) * 1946-09-12 1951-10-30 Kelley Koett Mfg Company X-ray apparatus

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE625011C (de) * 1932-12-17 1936-02-01 Bbc Brown Boveri & Cie Elektromagnetisches Wechselstromschuetz
DE691080C (de) * 1936-11-04 1940-05-16 Otto Muck Einrichtung zum Schalten eines Wechselstromkreises
FR863046A (fr) * 1939-01-26 1941-03-21 Thomson Houston Comp Francaise Perfectionnements aux circuits de dispositifs à décharge
DE904916C (de) * 1939-04-27 1954-02-25 Aeg Steuerverfahren fuer elektrische Hoechstspannungsroehren
US2453486A (en) * 1945-01-01 1948-11-09 Picker X Ray Corp Waite Mfg Electronic timer
US2561085A (en) * 1946-06-01 1951-07-17 Westinghouse Electric Corp Automatic exposure timer
US2438303A (en) * 1947-02-28 1948-03-23 Simmon Brothers Inc Device for making color prints
US2494218A (en) * 1947-07-03 1950-01-10 Picker X Ray Corp Waite Mfg Stabilizer with condenser modulator
US2679598A (en) * 1950-12-04 1954-05-25 Westinghouse Electric Corp X-ray apparatus
US2747104A (en) * 1951-10-06 1956-05-22 Gen Electric Interval timing apparatus
DE951020C (de) * 1951-11-25 1956-10-18 Siemens Ag Drehstromschuetz fuer synchrones Ausschalten, dessen Kontakte zwecks Vermeidung von Schaltfeuer kurz vor dem Nulldurchgang des Stromes geoeffnet werden

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2473922A (en) * 1949-06-21 Breathing indicator
US2003992A (en) * 1934-06-08 1935-06-04 Gen Electric Time delay circuit controlling apparatus
US2150440A (en) * 1936-06-10 1939-03-14 Western Union Telegraph Co Magnetic and resonator selector for carrier conveyers
US2165048A (en) * 1937-08-26 1939-07-04 Westinghouse Electric & Mfg Co Electric discharge apparatus
US2282182A (en) * 1939-09-07 1942-05-05 Westinghouse Electric & Mfg Co Amplifier circuit
US2361172A (en) * 1940-07-31 1944-10-24 Westinghouse Electric & Mfg Co Electronic power factor relay overload protection
US2413020A (en) * 1943-05-19 1946-12-24 Photoswitch Inc Electronic relay
US2401289A (en) * 1943-07-22 1946-05-28 Nasa Photoelectric timer for roentgen photography
US2422020A (en) * 1945-03-27 1947-06-10 Gen Electric Electric control circuit
US2573029A (en) * 1946-09-12 1951-10-30 Kelley Koett Mfg Company X-ray apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2958782A (en) * 1958-01-13 1960-11-01 Gen Electric Electronic timer
US2993145A (en) * 1958-04-30 1961-07-18 Bell Telephone Labor Inc Switching apparatus
US3046451A (en) * 1958-10-01 1962-07-24 Westinghouse Electric Corp Switching circuit
US3119932A (en) * 1960-02-12 1964-01-28 Philips Corp Polyphase current switching device for an x-ray tube supply circuit
US3094618A (en) * 1961-05-23 1963-06-18 Picker X Ray Corp X-ray tube protection mechanism
US3440422A (en) * 1965-06-24 1969-04-22 Picker Corp Biplane x-ray image system

Also Published As

Publication number Publication date
GB780982A (en) 1957-08-14
US2909666A (en) 1959-10-20
DE1010657B (de) 1957-06-19
FR74415E (fr) 1960-12-19
GB752971A (en) 1956-07-18
JPS325672B1 (nl) 1957-07-29
DE1110769B (de) 1961-07-13
JPS3519055Y1 (nl) 1960-08-10
NL105205C (nl) 1963-02-15
FR1167459A (fr) 1958-11-25

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