US2617047A - X-ray apparatus - Google Patents
X-ray apparatus Download PDFInfo
- Publication number
- US2617047A US2617047A US115408A US11540849A US2617047A US 2617047 A US2617047 A US 2617047A US 115408 A US115408 A US 115408A US 11540849 A US11540849 A US 11540849A US 2617047 A US2617047 A US 2617047A
- Authority
- US
- United States
- Prior art keywords
- voltage
- tube
- load
- proportional
- resistance
- Prior art date
- 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
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Classifications
-
- 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
- H05G1/48—Compensating the voltage drop occurring at the instant of switching-on of the apparatus
Definitions
- This invention relates to X-ray apparatus pro-V vided with automatic control.
- the maximum permissible load is smaller according as its duration is longer. If a given X-ray tube may be loaded for one sec- ⁇ ond with a, maximum power ofv Nikw., a load of one tenth of a second duration may-be, ⁇ for example, 1.4 N kw. but-a load of, say, 5 secs.
- N duration must not be in excess of 0.6 N kw.'
- the number of N may vary widely forA different types of tubes; as a rule itlliesgbetween 5 and 20 but even the factors Varying with time (in the said example 1.4 for 0.1 sec. and 0.6 for'5 sec.) vary considerably for the varioustyp'esof tubes.
- Modern X-ray apparatus comprise a controldevice for the load quantities of the tube, which automatically adapts the load on the tube to the load characteristic curve, the current -being adjusted as a, function ofY the duration of loading and of the voltage across the tube.' which* is generally variable between 50 and 100 kv.A
- the ordinate of each point of an arcuate surface ABCD is a measureof the maximum current intensity which is permissible at a Voltage and for a, length ofgtime, the values of which are determined by the distances from the two vertical coordinateA planes. It is desirable that with the use of the current intensity which is adjustedby the automatic contrlde'vice, the values determined by this plane should be approximated to the greatest possible extent. is carried out in practice byusing a variable resistance included in the. primaryv circuit of the filament-supply transformer or by connecting into the circuit'a voltage source which contributes to or counteracts the effect of thelament-sup-A ply transformer. The controlemember of this resistance or the switches by which this voltage' is connected into the circuit are coupled with the voltage control-member orvl with the load duration control member or with both.
- Fig. 1 shows how in the latter case the steps may be chosen,f-;namely in This' 2 three steps in accordance with the voltage chosenv and in three step's'in' accordance' Withthe time interval chosen', so ⁇ that thecurrent vintensity may be'adjusted to ⁇ nine values' in all.
- the product'IX't is plotted as a function'pf the tubfe' Voltage U and the time interval' t.
- the'surface EFGH corresponds to the load characteristic' curve of the X-ray tube.
- the present invention provides a control of improved operation which can be provided at low cost.
- the voltage loss is taken into account and the invention is based on recognition of the fact that at a given ratio between the resistance lying (as viewed from the mains) in front of the autotransformer controlling the voltage and that following this transformer, the voltage loss is constant throughout the voltage control-range if the load on the tube is kept constant, It has been found possible thus to compensate the voltage loss throughout the range of voltage-control by increasing the primary voltage of the highvoltage transformer by an amountvarying with the load.
- Fig. 3 shows the greatly simplified circuit-diagram of an X-ray apparatus, in which T1 is an autotransformer and T2 a high-voltage transformer.
- UN designates the mains voltage and RN the resistance of the mains as far as the autotransformer
- RA designatesrthe resistance of the autotransformer transferred to the output side
- RH the resistance of the high-voltage transformer, including that of any rectifying tubes used, transferred to the high-voltage side of the said transformer.
- the total resistance of the circuit appearing at the high-voltage side of the transformer T2 is calculated as follows:
- Fig. 4a shows the control-range which extends, for example, from 50 to 100 kv. for U2 and in which the voltage loss'isrequired to be constant at a definite load (kw.).
- the limit values of this range are I and II. Since the load is required to be constant, the current intensity varies in this range by a factor 2, as indicated in Fig. 4b.
- Fig. 6 shows the variation of the auxiliary voltage U as a function of the load for a denite, adequately chosen mains constant which is such that most mains connections exhibit this constant or else, may be brought in accordance therewith by use of a ballast resistance.
- mains constant of, for example, l/3802 (ohm/volt2) (l ohm for a 380 volts mains and 0.33 ohm for a 220 volts mains).
- the characteristic impedances of the apparatus are purposely chosen to be such that the Equation 1 is fulfilled.
- the voltage loss can be compensated in a simple manner.
- the load on the X-ray tube is required to vary with the duration of the load, it is only necessary to couple the time adjusting member with a corresponding member for controlling the auxiliary voltage. This may be seen from Fig. 6.
- the load Nk at the minimum time of loading to be chosen is such that for compensating the voltage loss the amount dUk must be added. With increase in time the load drops to that which is associated with the longest time interval and is designated N1.. at which the voltage dUL is required to be added for compensation. .A I
- the compensating voltage is resolved into a constant component A and a component varying with time between Band +B.
- This is particularly advantageous if two or more tubes of diiferent power are required to be connected to the supply device. This is set out more fully with reference to Fig. 7. IIt is assumed that for two tubes of different load capacity the voltage loss is required to be compensated. Without introducing a great error, the component B, which varies with time, may be kept constant and the component A or Az may alone be chosen to correspond to the tube which is brought into operay tion.
- a simplied" ycircuit-diagram of an X-ra-y apparatus''according tothe invention is shown in Fig.-8, itbeing assumed that this apparatus comprises two ltubes of different load capacity.
- theL tube current as a function ofthe lOading-'timeand of the tube voltage exhibits a variation as represented, for example, in Fig. 1 'bythe' surface ABCD.
- both the shaft I for voltage-control andthe shaft'2 for-time control are provided with variable 'resistances 3 and 4, the variation of which is chosen'so as to'fulll this condition.
- variable 'resistance-'Beets to connect into the filament-supply circuit'a-resistance suitable for each o fv the twoL tubes;
- the filament-supply current forY 'each v ⁇ of* the ⁇ X-ray tubes I1 and I8 ⁇ is supplied from the filamentsupply transformer I9.
- Thelatter is fed in a conventional manner through a voltage stabilizing device 6 from an autotransformer 'I.
- the autotransformer 1 is connected to the mains 8.
- a resistance 9 serves to adjust the mains resistance to the desired value.
- a controlley II] has the function of supplying the correct Voltage to the autotransformer in the event of voltage fluctuations in the mains. The correct voltage may be read from a voltmeter I I.
- the high-voltage generator comprises a transformer I2, the secondary alternating current of which is converted into direct current by rectifying tubes I3 and supplied at will through arms Ill and I of a switch to either of the two X-ray tubes I1 and I8.
- the auxiliary voltage dU for compensatingthe voltage loss is added as follows:
- the component A is taken directly from an auxiliary winding 2U, which is provided on the control transformer.
- the component B is taken from a. winding 22 with. the. use lof;- a control-member :2Iz,xwhich.ris coupled to' .the :time selector.;
- The..winding.:2.2 isuconnected to the rcontrol-transformer.. ⁇
- the component B. isf added through a .transformer 23 to.A the voltagewhichlacts on the primary winding of the' high-voltage.transformer. I2.:
- Thecur.- rent is switched onrand off ;by anelectromagnetizcally controlled switch .24', Vtheenergizing current of whichis controlled. by a time switch V25.'
- energizing 'the anode-of the X ⁇ rayVV tube means .to couple'thefhighand low-tension circuits to a source of electricalpowe-rhaving -a given-.electrical resistance proportionall to the electrical resistance of the high-tensionvcircuit for which the voltage loss across the tube is proportional to thel input power-to the tube,4 and means included-in the high-tension circuit for compensating for the voltage-lossresulting/with current ow in the'high-tensioncircuit and from the source comprising means to derive a relatively constant voltage component proportional to the voltage applied from the source.
- an adjustable inductor responsive to the adjustment of said tube timing means coupled to the source of electrical power for deriving a voltage proportional to the adjusted loading time of the tube, and means to add the voltage proportional to the adjusted loading time to the sum of the applied voltage and the voltage proportional to the applied voltage to thereby adjust the Voltage applied to the tube to the equivalent no-load voltage without compensation.
- a circuit arrangement for energizing an X-ray tube with automatic control of tube current comprising a low-tension circuit for energizing the cathode of the X-ray tube including means to adjust the loading time of the tube for a predetermined time interval.
- a separate hightension supply circuit having a given electrical resistance for energizing the anode of the X-ray tube, a common transformer for coupling the highand low-tension circuits to a source of electrical power having an electrical resistance proportional to the electrical resistance of the high-tension circuit for which the voltage loss across the tube is proportional to the input power to the tube, and means included in the hightension circuit for compensating for the voltage loss resulting with current flow in the hightension circuit and from the source comprising a transformer winding coupled to said common transformer for deriving a relativelyconstant voltage component proportional to the voltage applied from the source through said common transformer in series with said high-tension supply circuit, an adjustable inductor responsive to the adjustment of said tube timing means coupled to said common transformer for vderiving a voltage proportional to the adjusted loading time of the tube, and a control transformer in the high-tension supply for adding the voltage proportional to the adjusted loading time to the sum of the applied voltage and the voltage proportional to the applied voltage to thereby adjust ⁇ the voltage applied to the tube to the equivalent
- a circuit arrangement for energizing an X-ray tube with automatic control of tube current comprising a low-tension circuit for energizing the cathode of the X-ray tube including means to adjust the loading time of the tube for aipredetermined time interval, a separate high-tension circuit having a given electrical resistance for energizing the anode of the X-ray tube, means to couple the high-,and low-tension circuits to a source of electrical power including an electrical resistance for adjusting the resistance of said source to a value proportionaluto the electrical resistance of the high-tension circuit for which the voltage loss across ,the tube is proportional to the input power to the tube, and means included in the high-tension circuit for compensating for the voltage loss resulting with current flow inthe high-tension circuit and from the source comprising means to derive a relatively constant voltage component proportional to the voltage applied from ⁇ the source, means to add the voltage thus derivedto the voltage applied from the source to the hightension circuit, means to derive a voltage vproportional
- 5.1K circuit arrangement for energizing an X-ray tube with automatic control of tube current comprising a low-tension circuit for energizing the cathode of the X-ray tube including means to adjust the loading time of the tube for a predetermined time interval and means to control the current to the cathode proportional to the adjusted voltage applied to the tube, a separate high-tension circuit having a given electrical resistance for energizing the anode of the X-ray tube, means to couple the highand low-tension circuits to a source of electrical power including an electrical resistance for adjusting the resistance of said source to a value proportional to the electrical resistance of the high-tensionvcircuit for which the voltage loss across the tube is proportional to the input power to the tube, and means included in the high-tension circuit for compensating for the voltage loss resulting with current ow in the high-tension circuit and from the source comprising means to derive a relatively constant voltage component proportional to the voltage applied from the source, means to add the voltage thus derived to' the voltage applied
Landscapes
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Toxicology (AREA)
- X-Ray Techniques (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL142577A NL72521C (nl) | 1948-09-30 | 1948-09-30 | inrichting voor het maken roentgenopnamen |
Publications (1)
Publication Number | Publication Date |
---|---|
US2617047A true US2617047A (en) | 1952-11-04 |
Family
ID=19866677
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US115408A Expired - Lifetime US2617047A (en) | 1948-09-30 | 1949-09-13 | X-ray apparatus |
Country Status (7)
Country | Link |
---|---|
US (1) | US2617047A (de) |
BE (1) | BE491389A (de) |
CH (1) | CH281880A (de) |
DE (1) | DE803178C (de) |
FR (1) | FR996351A (de) |
GB (1) | GB677145A (de) |
NL (1) | NL72521C (de) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2936376A (en) * | 1956-10-31 | 1960-05-10 | Nl Rontgen App Nfabriek Nv | Installations for making X-ray photographs |
US3027460A (en) * | 1958-03-11 | 1962-03-27 | Philips Corp | X-ray device |
KR100475974B1 (ko) * | 1994-08-05 | 2005-09-06 | 시오노기세이야쿠가부시키가이샤 | 변성이방지된경질젤라틴캡슐및그의제조방법 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2137647A (en) * | 1937-10-28 | 1938-11-22 | Picker X Ray Corp Waite Mfg | X-ray apparatus |
US2351486A (en) * | 1942-07-07 | 1944-06-13 | Westinghouse Electric & Mfg Co | X-ray exposure system |
US2379125A (en) * | 1942-07-04 | 1945-06-26 | Westinghouse Electric Corp | X-ray tube protective system |
US2512193A (en) * | 1945-09-20 | 1950-06-20 | Westinghouse Electric Corp | Milliamperage stabilizer |
-
1948
- 1948-09-30 NL NL142577A patent/NL72521C/xx active
- 1948-10-02 DE DEP8071A patent/DE803178C/de not_active Expired
-
1949
- 1949-09-13 US US115408A patent/US2617047A/en not_active Expired - Lifetime
- 1949-09-27 GB GB24751/49A patent/GB677145A/en not_active Expired
- 1949-09-28 FR FR996351D patent/FR996351A/fr not_active Expired
- 1949-09-28 CH CH281880D patent/CH281880A/de unknown
-
1950
- 1950-09-28 BE BE491389A patent/BE491389A/fr unknown
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2137647A (en) * | 1937-10-28 | 1938-11-22 | Picker X Ray Corp Waite Mfg | X-ray apparatus |
US2379125A (en) * | 1942-07-04 | 1945-06-26 | Westinghouse Electric Corp | X-ray tube protective system |
US2351486A (en) * | 1942-07-07 | 1944-06-13 | Westinghouse Electric & Mfg Co | X-ray exposure system |
US2512193A (en) * | 1945-09-20 | 1950-06-20 | Westinghouse Electric Corp | Milliamperage stabilizer |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2936376A (en) * | 1956-10-31 | 1960-05-10 | Nl Rontgen App Nfabriek Nv | Installations for making X-ray photographs |
US3027460A (en) * | 1958-03-11 | 1962-03-27 | Philips Corp | X-ray device |
KR100475974B1 (ko) * | 1994-08-05 | 2005-09-06 | 시오노기세이야쿠가부시키가이샤 | 변성이방지된경질젤라틴캡슐및그의제조방법 |
Also Published As
Publication number | Publication date |
---|---|
DE803178C (de) | 1951-03-01 |
CH281880A (de) | 1952-03-31 |
BE491389A (fr) | 1950-03-28 |
NL72521C (nl) | 1953-06-15 |
GB677145A (en) | 1952-08-13 |
FR996351A (fr) | 1951-12-18 |
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