SU1497772A1 - X-ray generator - Google Patents

Abstract

The invention relates to the field of X-ray technology, and more specifically to X-ray generators with high-frequency conversion in the main circuit. The purpose of the invention is to improve the quality of the generated radiation without using an output capacitive filter and reduce the requirements for the element base. To do this, auxiliary windings 10, 11 have been introduced into the high voltage transformers 4.5 of the generator, which have a deep connection to the primary windings 6.7 of these transformers 4.5 and are connected to one output of the controlled constant voltage source 1 via rectifiers 15, 16 and switching transistors 17, 18. Inverters 2, 3 are connected to the same output of source 1 via switching transistors 19, 20. Transistors 19, 20 work in phase with the thyristors of inverters 2, 3, and transistors 17, 18 work in antiphase with transistors 19, 20. The operation of the inverter 3 is shifted n quarter period relative to the inverter 2. The diagonals DC high voltage rectifiers 12, 13 are connected in parallel to each other. 2 Il.

Description

t

(21) 4371480 / 28-25 (22) 02.12.87 (46) 07.30.89. Bup. Number 28

(71) Moscow Research Institute of Radiology and Radiology

(72) S.G.Zhut, G.A.Sulkin, B.Ya.Mishkinis and E.G.Chikirdin

(53) 621.386 (088.8)

(56) Published for the Federal Republic of Germany

No. 2908767, CP. H 05 G 1/32, 1980.

Laid out for VKA FRG number 2814320, cl. H 05 G I / I2, 1979.

(54) X-RAY GENERATOR

(57) The invention relates to the field of X-ray technology, and more specifically to X-ray generators with high-frequency conversion in the main circuit. The purpose of the invention is to increase the quality of the generated radiation.

without using output capacitance2

. filter and reduce the requirements for element base. To do this, auxiliary windings 10, II are injected into high-voltage transformers 4, 5 of the generator, which have a deep connection to the primary windings 6, 7 of these transformers 4, 5 and are connected to one output of an adjustable constant-voltage source 1 via rectifiers 15, 16 and switching transistors 17, 18. Inverters 2, 3 are connected to the same (source I water through the switch transistors 19, 20, Transistors 19, 20 work in phase with the inverters thyristors 2, 3, and transistors 17 with transit storami 19, 20. Work inverter 3 shift chickpeas for a quarter of the period regarding the operation of the inverter 2, the diagonal direct current of the high-voltage rectifiers 12, 13 are connected in parallel to each other.

(L

with

-4j

The invention relates to X-ray technology, and more specifically to X-ray generators with high-frequency conversion in the main circuit.

The purpose of the invention is to improve the quality of the generated radiation without using an output capacitive filter and reduce the requirements for the element base.

On fng, 1 the scheme of the x-ray generator is depicted; Fig. 2 shows voltage diagrams on secondary windings of high voltage transformers and diagonal x direct current of high voltage rectifiers.

X-ray generator contains adjustable constant-voltage source 1 (for example, a controlled mains rectifier and a smoothing filter), two thyristor inverters 2 and 3, two high-voltage transformers 4 and 5 with primary 6 and 7, secondary 8 and 9, and auxiliary

through the circuit 25, the reference transistors 19 equalizing the electrode to the delay generator, corresponding to the transistors 17 equalizing the electrode outputs of the elements H

JQ rye their entrances to the course of setting the gene do 25 delay

Fig. 2 shows the secondary conditions.

15 juice transmma 29 voltage winding 9 high volt mater 5, the diagram on the diagonal is constant

20 voltage rectifier 31 voltage of a high current is high 13;

X-ray

10 and 1 1 windings, two high voltage 25 as follows.

rectifier 12 and 13, diagonals of alternating current connected to the secondary windings 8 and 9 of high voltage transformers 4 and 5, and diagonals of direct current connected in parallel to one another, To the diagonal of direct current of high voltage rectifiers 12 and 13 are connected X-ray tube 14 , To the auxiliary windings 10 and 11 of high voltage transformers 4 and 5, connected on their primary sides, alternating current diagonals are connected to two rectifiers 15 and 16, between which diagonals and one output of adjustable source 1 are constant This voltage is connected to two switching transistors 17 and 18. The other two switching transistors 19 and 20 are connected between the same output of the source 1, the constant x of the direct current of which is the voltage and inverter 2 and 3. Control unit 21 X-ray generator contains master oscillator 22, two distributors 23 and 24 pulses, a quarter delay circuit 25 and two elements HE 26 and 27. The outputs of the distributor 23 pulses are connected to the thyristors of the inverter 2, and the outputs of the distributor 24 pulses to the thyristors of the inverter 3, Output bum The auxiliary generator 22 is connected to the input of the distributor 23 pulses directly, and 24 inputs to the input of the distributor

50

The voltages shown in diagrams 30 and 31 are applied to the X-ray tube 14. Thus, on the X-ray tube all the time there is a constant voltage coming either from one of the rectifiers 12 and 13, or from both of these rectifiers 12 and 13, which is ensured by the parallel connection of direct current di- agonals on the circuits 12 and 13.

Auxiliary winding 10 high-voltage transformer 4, rectifier 15 and commuting transis

through the circuit 25 delay. The switching transistors 19 and 20, with their control electrodes, are connected to a generator oscillator 22 and a delay circuit 25, respectively. The switching transistors 17 and 18 are connected by their control electrodes to the outputs of the HE elements 26 and 27, which are connected by their inputs to the output of the master oscillator 22 and the output 25 of the delay, respectively.

FIG. 2 shows a voltage diagram 28 on the secondary winding 8 of a high voltage transformer 4, a voltage diagram 29 on the secondary winding 9 of a high voltage transformer 5, a voltage diagram 30 on a diagonal of a high voltage rectifier 12, and a voltage diagram 31 on a constant diagonal current high-voltage rectifier 13,

X-ray generator works

A constant voltage from the output of an adjustable source 1 of constant voltage is supplied to inverters 2 and 3, which convert it to an alternating rectangular voltage amplified by high-voltage transformers 4 and 5, Inverters 2 and 3 operate with a quarter offset from each other , what

is provided by introducing a delay circuit 25 into the control unit 21 between the master oscillator 22 and the pulse distributor 24. The voltages on the secondary windings 8 and 9 of high voltage transformers 4 and 5 are of the form shown in diagrams 28 and 29. These voltages are supplied on an AC diagonal of high voltage rectifiers 12 and 13, on the diagonal

The voltages shown in diagrams 30 and 31 are applied to the X-ray tube 14. Thus, on the X-ray tube all the time there is a constant voltage coming either from one of the rectifiers 12 and 13, or from both of these rectifiers 12 and 13, which is ensured by the parallel connection of the direct current di- and agonals of the heaters 12 and 13.

Auxiliary winding 10 high-voltage transformer 4, rectifier 15 and commuting transis5iZ

The tori 17 and 19 are used for the instantaneous quenching of the inverter 2 thyristors, and the auxiliary winding I1 of the high voltage transformer 5, the rectifier 16 and the switching transistors 18 and 20 serve to quench the thyristors of the inverter 3, while the transistors 19 and 20 are in phase with the inclusion of the inverters 2 thyristors and 3 | and transistors 17 and 18 are turned on when transistors 19 and 20 are turned off. For such work, transistors 18 and 17 are connected to the outputs of the delay circuit 25 and the master oscillator 22, respectively, through the terminals. NOT 27 h 26, Auxiliary windings 10 and 11 of the high-voltage transformers 4 and 5 have a deep connection with their primary windings 6 and 7, which is achieved, for example, by co-winding both windings.

When using the proposed X-ray generator, the ripple level is reduced without using output capacitive (} iltra, which eliminates the drawbacks associated with the use of such a filter. In addition, the switching of transistors occurs with virtually no dynamic losses, while the currents for high-voltage rectifier diodes are sharper - 1 1 bodies are small, as a result of which the quality requirements of Hz1 sock-woven transformers are reduced because the requirements for the smallness of the leakage inductance lose their critical spine.

All transistor control circuits in the proposed X-ray generator lead to ground, which facilitates coordination with the digital control circuit.

26

Claims (1)

The invention X-ray generator containing an adjustable source of DC voltage, parallel to the connection to its outputs two high-frequency inverters, two high-voltage transformers, the primary winding of each of which is connected to the output of one inverter, two high-voltage rectifiers connected by AC diagonals to the secondary windings of high-voltage transformers, an X-ray tube connected to the diagonal and direct current of high-voltage rectifiers, and an inverto control unit with means of phase shift operation of one inverter by a quarter period relative to the phase operation of another inverter, characterized in that, in order to improve the quality of the generated radiation without using an output capacitive filter and reducing requirements for the element base, each high-voltage transformer is equipped with an auxiliary winding connected on its primary side, two additional rectifiers are introduced, diagonals of alternating current connected to the auxiliary windings of high-voltage transformers, and four switching transistors, two of which are connected between the inverters and one regulated output DC source, and the other two - between the diagonals of the DC additional rectifiers and the same output adjustable source full-time student DC voltage, DC diagonals of high-voltage rectifiers are connected in parallel to each other, and the inverter control unit is equipped with additional outputs connected to the control electrodes of the switching transistors. FIG. 2