JPH0864387A - Power source circuit for x-ray high voltage device and x-ray ct device using it - Google Patents

Abstract

PURPOSE: To enable the use even with an AC power source at 200 V and an AC power source at 400V without using a large step-down power source transformer, and to enable the fitting thereof to a frame rotating part or the like for use. CONSTITUTION: Input power source voltage is taken by a rectifying unit 11, and it is rectified so as to generate the direct current power source voltage, and a first and a second capacitors 12, 13 are connected in series or in parallel in response to the value of the input power source voltage. The first and the second capacitors 12, 13 are charged with the direct current power source voltage output from the rectifying unit 11, and the direct current power source voltage charged in the first and the second capacitors 12, 13 are respectively converted from DC to DC by a first and a second DC-DC converters 14, 15 so as to generate the direct current voltage at a high voltage.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to X-ray C using high voltage.
The present invention relates to a power supply circuit for an X-ray high-voltage device used in a T-device, an X-ray diagnostic device, and the like, and an X-ray CT device using the same.

[0002]

2. Description of the Related Art For an X-ray CT apparatus and an X-ray diagnostic apparatus using a high voltage, one of the standards for commercial power sources in Japan,
For example, an X-ray high voltage device is manufactured by using AC200V as a power source, and as shown in FIG.
It is possible to connect the X-ray high voltage device 102 to a power tap or the like and supply the high-voltage DC voltage obtained by the X-ray high voltage device 102 to a gantry device of an X-ray CT device or an X-ray diagnostic device. Many.

[0003]

By the way, when such an X-ray CT apparatus or an X-ray diagnostic apparatus is used, a switchboard 1 is used.
01 has no AC200V power tap, for example, when used in a place where the standard of the commercial power source is different, such as in a foreign country, etc., from the power tap of AC400V among the power taps on the switchboard 103 as shown in FIG. Along with the power supply, the large step-down power transformer 104 transforms AC400V into AC200V, and then supplies this to the X-ray high-voltage device 102 to apply the high voltage to the gantry device of the X-ray CT device or the X-ray diagnostic device. DC voltage is often supplied.

For this reason, the X-ray high-voltage device 102 is downsized and attached to the gantry rotating part of the X-ray CT device or the X-ray diagnostic device, and when there is no AC200V power tap even if it is attempted to improve the space utilization efficiency. , A large step-down power transformer 10 for the X-ray high voltage device 102
However, there is a problem that it is difficult to improve the space utilization efficiency because the external components such as 4 must be externally attached.

In view of the above circumstances, the present invention is an AC20 without using a large step-down power transformer or the like.
To provide a power supply circuit for an X-ray high-voltage device that can be used with a 0 V power supply or an AC 400 V power supply and can be attached to a gantry rotating part and the like, and an X-ray CT device using the same. It is an object.

[0006]

In order to achieve the above object, the power supply circuit for an X-ray high voltage apparatus according to the first invention of the present application converts an AC input power supply voltage into a DC voltage and supplies the DC voltage to an X-ray tube. In a power supply circuit for an X-ray high-voltage device, a rectification unit that rectifies the AC input power supply voltage to generate a DC voltage, and is connected in parallel or in series according to the value of the input power supply voltage, and is output from the rectification unit. Charged with DC power supply voltage 2
It is characterized in that it is provided with a plurality of capacitors and two DC-DC converters that respectively perform DC-DC conversion of the DC voltage charged in the capacitors to generate a high-voltage DC voltage.

In the power supply circuit for the X-ray high voltage apparatus according to the second invention of the present application, in the first invention, when the capacitors are connected in series and used, the capacitors are charged. When the DC voltage becomes unbalanced, a voltage correction unit for detecting this and adjusting the value of the DC voltage charged in each capacitor is provided.

Further, in the power supply circuit for the X-ray high voltage apparatus according to the third invention of the present application, in the second invention, the voltage correction unit detects a difference between the DC voltages charged in the capacitors. When a difference between the DC voltages is detected by the voltage shift detection unit and the voltage shift detection unit, a current is intermittently applied to the coil to generate an electromotive voltage, and the electromotive voltage charges the capacitors. And a switching unit that balances the direct current voltage.

An X-ray CT apparatus according to the fourth invention of the present application is characterized by using the power supply circuit for the X-ray high voltage apparatus according to the first to third inventions.

[0010]

According to the power supply circuit for the X-ray high-voltage device of the present invention constructed as described above, the rectifying unit takes in the AC input power supply voltage and rectifies the AC input power supply voltage to generate the DC voltage. The two capacitors are charged by the two DC-DC converter units while the two capacitors are connected in parallel or in series in accordance with the value of and the capacitors are charged by the DC voltage output from the rectification unit. By converting each DC voltage into a DC-DC conversion to generate a high DC voltage, the AC20 can be converted without using a large step-down power transformer or the like.
It should be possible to use either a 0V power supply or an AC 400V power supply.

When the capacitors are connected in series and used, when the DC voltage charged in the capacitors becomes unbalanced, the voltage correction unit detects this and charges the capacitors. By adjusting the value of the DC voltage being applied, a stable voltage can always be supplied.

Further, in the X-ray CT apparatus of the present invention, the above X
By mounting the power circuit for the line high-voltage device on the gantry rotating part, etc., a large step-down power transformer is not required even at AC 400 V, space is effectively used, and the high-voltage source and high-voltage destination It is possible to place and in close proximity.

[0013]

1 is a block diagram showing an example of an X-ray CT apparatus using an embodiment of a power supply circuit for an X-ray high voltage apparatus according to the present invention.

The X-ray CT apparatus 1 shown in the figure has a bed apparatus 2 on which a patient to be examined is placed, a power supply circuit 10 for the X-ray high-voltage apparatus in a gantry rotating unit 9, and the bed apparatus 2 described above. A gantry device 3 that collects X-ray data while irradiating X-rays to a patient placed on the patient, and controls the gantry device 3 and the bed device 2 based on the operation content of a doctor (or an engineer). An operation console device 5 for generating an X-ray sectional image of the patient based on the X-ray data collected by the gantry device 3 and displaying the image on the image display device 4.

The patient to be examined is placed on the bed device 2
After adjusting the height, position, etc. of the patient placed on the bed apparatus 2 based on the operation content of the operation console apparatus 5 placed on the tabletop, the gantry apparatus 3 having a hole in the central portion thereof is X-rays are emitted from an X-ray tube mounted on the gantry device 3 while passing through the patient, X-ray data transmitted through the patient is collected, and an X-ray cross-sectional image of the patient is created based on the X-ray data. This is displayed on the image display device 4 of the console device 5.

Thereafter, of the X-ray cross-sectional images displayed on the image display device 4, the X-ray cross-sectional images required for diagnosis are transferred to an imager device (not shown) and printed on the film. Used for diagnosis by a doctor.

In this case, the gantry rotating part 9 of the gantry device 3
The power supply circuit 10 for the X-ray high-voltage device provided in FIG.
As shown in FIG. 1, the rectification unit 11, the first capacitor 12, and the first
DC-DC converter unit 14 and second capacitor 13
And the second DC-DC converter unit 15 and the voltage correction unit 1
6, and when the power supply voltage is AC400V, the first and second capacitors 12 and 13 are connected in series as shown in FIG. Capacitors 12, 13
To the first and second DC-DC converter units 1
Supply to 4 and 15. Then, in each of the DC-DC converters 14 and 15, a DC power supply voltage of DC 70 KV is generated, and D is generated between the anode 18 and the cathode 19 of the X-ray tube 17.
Apply C140KV. The power supply voltage is AC200V
In this case, the wiring is switched to change the first and second wirings as shown in FIG.
DC300V obtained by the rectification unit 11 by connecting the capacitors 12 and 13 in parallel is applied to the first and second capacitors 12 and 13, respectively, and DC 70 KV is applied to the first and second DC-DC converter units 14 and 15, respectively. The DC power supply voltage of the X-ray tube 17 is generated, and the anode 18 and the cathode 1 of the X-ray tube 17 are generated.
Apply 140 KV DC between 9 points.

That is, the basic circuit configurations of FIGS. 2 and 3 are the same, and the power supply voltage supplied is 200 V or 400.
Change the wiring connection with V. The wiring can be changed by using a switch or the like, but in practice, the supply voltage is fixed at 200 V or 400 V, so that the function of changing the input voltage is not necessary. Here, since the basic configuration of the circuit is the same regardless of whether the supply voltage is 200 V or 400 V, there is an advantage in that the circuit wiring can be easily set to adapt to the supply voltage.

The rectifying unit 11 shown in FIGS. 2 and 3 is an AC400V or AC20 which is supplied from a switchboard of a commercial power source.
It is equipped with four diodes 20, 21, 22, and 23 that take in an AC voltage of 0 V and rectify it in full wave.
When 400V is input, it becomes 60 by full wave rectification.
A direct current voltage of 0 V is generated, and this is used as the first capacitor 12
To the second capacitor 13 and the voltage correction unit 16, and when AC200V is input, a DC voltage of 300V is generated by full-wave rectification, and this is supplied to the first capacitor 12 and the second capacitor 13. Supply.

The first capacitor 12 is a large-capacity capacitor charged by the DC voltage output from the rectification unit 11, and the AC voltage supplied from the switchboard is A
At C400V, DC3 is connected in series with the second capacitor 13 as shown in FIG. 2 and divided by a DC voltage of 600V DC output from the rectifying unit 11.
While being charged to 00V, the DC voltage of 300V obtained by this charging operation is supplied to the first DC-DC converter unit 14. Further, when the AC voltage supplied from the switchboard or the like is AC200V, the wiring is switched and connected in parallel with the second capacitor 13 as shown in FIG. 3, and the DC voltage of 300V output from the rectifier 11 causes DC300V. The DC voltage of 300V obtained by this charging operation is charged to the first DC-DC converter unit 14 and the second DC-DC.
It is supplied to the converter unit 15.

The first DC-DC converter section 14 is 300
It is a circuit that takes in a DC voltage of V and DC-DC converts it to generate a DC voltage of 70 KV. When the AC voltage supplied from a switchboard is 400 V AC, it is output from the first capacitor 12 as shown in FIG. The DC voltage of 300V is converted to DC-DC and 70
When the DC voltage of KV is generated and is output from the positive output terminal to be applied to the anode 18 of the X-ray tube 17 and the AC voltage supplied from the switchboard is AC200V, the wiring is switched and As shown in (3), the DC voltage of 300 V output from the first and second capacitors 12 and 13 is taken in, DC-DC converted to generate a DC voltage of 70 KV, and this is output from the positive output terminal to output the X-ray. It is applied to the anode 18 of the tube 17.

The second capacitor 13, like the first capacitor 12, is a large-capacity capacitor charged by the DC voltage output from the rectifying unit 11,
When the AC voltage supplied from the switchboard is 400V AC, the voltage is divided by 600V output from the rectifying unit 11 connected in series with the first capacitor 12 as shown in FIG. At the same time, the DC voltage of 300V obtained by this charging operation is supplied to the second DC-DC converter unit 15. In addition, the AC voltage supplied from the switchboard is AC200V.
At this time, the wiring is switched and the first wire is switched as shown in FIG.
The capacitor 12 is connected in parallel with the capacitor 12 and is charged by the DC voltage of 300V output from the rectification unit 11 to DC 300V, and the DC voltage of 300V obtained by the charging operation is supplied to the first DC-DC converter unit 14. , And the second DC-DC converter unit 15.

Similarly to the first DC-DC converter section 14, the second DC-DC converter section 15 takes in a DC voltage of 300V and DC-DC converts it to 70K.
This is a circuit for generating a DC voltage of V, and when the AC voltage supplied from the switchboard is 400V AC, the DC voltage of 300V output from the second capacitor 13 is taken in as shown in FIG. 2, and this is DC-DC converted. Then 70KV
Of the DC voltage is generated from the negative output terminal and applied to the cathode 19 of the X-ray tube 17 and the AC voltage supplied from the switchboard is AC200V,
The wiring is switched and the DC voltage of 300 V output from the first and second capacitors 12 and 13 is taken in as shown in FIG. 3, and this is DC-DC converted to generate a DC voltage of 70 KV, and this is negatively output. It is output from the terminal and applied to the cathode 19 of the X-ray tube 17.

Further, the voltage correction unit 16 is provided with a voltage shift detection unit 25, a step-down converter unit 26, a step-up converter unit 27, and a coil 28 for PWM, and the AC voltage supplied from a switchboard or the like. Is AC
At 400V, as shown in FIG. 2, the value of the DC voltage connected to the rectifying unit 11 and the first and second capacitors 12 and 13 and charged in the first capacitor 12 and the second capacitor 13 are charged. When the DC voltage values are different from each other, it is detected to adjust the DC voltage values charged in the first and second capacitors 12 and 13 to balance them.

The voltage shift detector 25 includes two resistors 29 and 30 connected in series, and the value of the DC voltage charged in the first capacitor 12 and the second capacitor 13 are charged. The voltage obtained by adding the value of the DC voltage is divided to shift the amount from the ground potential, that is, the value of the DC voltage charged in the first capacitor 12 and the value of the DC voltage charged in the second capacitor 13. A detection voltage is generated according to the difference between and and is supplied to the step-down converter unit 26 and the step-up converter unit 27.

The step-down converter unit 26 includes a diode 31 which is conductive when the value of the detection voltage output from the voltage shift detecting unit 25 has a positive polarity, and a light emitting diode which emits light when the diode 31 is conductive. A PWM controller 33 having 32 and generating a PWM (pulse width modulation) control signal when the light emitting diode 32 is emitting light, and a switching FET 34 that is turned on / off by the PWM controller 33. And the FET connected to the source / drain of the FET 34
The diode 35 is provided for preventing the reverse bias of 34 and for transmitting the counter electromotive voltage of the PWM coil 28 to the first capacitor 12 and charging it.

When the value of the detected voltage output from the voltage shift detector 25 is positive, the diode 31 becomes conductive and the PWM controller 33 outputs a control signal to turn on / off the FET 34. Let As a result, when the FET 34 is in the ON state, the DC voltage charged in the first capacitor 12 is
Is applied to the coil 28 via
Current flows through the coil 28, the value of the DC voltage charged in the first capacitor 12 is reduced, and the coil 28
Magnetic energy is stored in. After this, the FET3
When the switch 4 is turned off, a counter electromotive voltage is generated in the coil 28, and this is applied to the second capacitor 13 via the diode 40 on the step-up converter 27 side to charge the second capacitor 13. The value of the DC voltage is increased. Hereinafter, the above-described operation is repeated until the difference between the value of the DC voltage charged in the first capacitor 12 and the value of the DC voltage charged in the second capacitor 13 becomes zero.

Further, the step-up converter unit 27 conducts when the value of the detection voltage output from the voltage shift detection unit 25 has a negative polarity, the diode 36 becomes conductive,
A PWM controller 38 that has a light emitting diode 37 that emits light when the diode 36 is conducting, and generates a PWM (pulse width modulation) control signal when the light emitting diode 37 emits light; Switching FETs that are turned on / off by the PWM controller 38
39 and the source / drain of the FET 39 to prevent the FET 39 from being reverse biased, or to transmit the counter electromotive voltage of the PWM coil 28 to the second capacitor 13 to charge it. And a diode 40 that operates.

When the value of the detected voltage output from the voltage shift detector 25 is negative, the diode 36 becomes conductive and the PWM controller 38 outputs a control signal to turn on / off the FET 39. To operate. As a result, when the FET 39 is in the ON state, the DC voltage charged in the second capacitor 13 is the FET 3
Is applied to the coil 28 via 9
At 8 the current flows and the value of the DC voltage charged in the second capacitor 13 is reduced and the coil 2
Magnetic energy is stored in 8. After this, the FET
When the switch 39 is turned off, a counter electromotive voltage is generated in the coil 28, which causes the step-down converter 26.
The value of the DC voltage applied to the first capacitor 12 via the side diode 35 and charged in the first capacitor 12 is increased. Hereinafter, the above-described operation is repeated until the difference between the value of the DC voltage charged in the first capacitor 12 and the value of the DC voltage charged in the second capacitor 13 becomes zero.

The coil 28 for PWM operates in cooperation with the step-down converter section 26 and the step-up converter section 27, and the first and second capacitors 12,
13 is an element for adjusting the value of the DC voltage charged in 13, and the FET 34 of the step-down converter unit 26.
When the power is turned on / off, the electric energy is converted into magnetic energy to lower the value of the DC voltage charged in the first capacitor 12 and increase the value of the DC voltage charged in the second capacitor 13. 1st, 2nd DC-
The DC voltage input to the DC converters 14 and 15 is balanced, and the step-up converter 27 is used.
When the FET 39 is turned on / off, the electric energy is converted into magnetic energy to reduce the value of the DC voltage charged in the second capacitor 13, and the value of the DC voltage charged in the first capacitor 12 is changed. The DC voltage input to the first and second DC-DC converter units 14 and 15 is balanced by raising the voltage.

As described above, in this embodiment, when the power supply voltage is 400 V AC, the first and second capacitors 1
2 and 13 are connected in series, and DC 600V obtained by the rectifying unit 11 is allocated to the first and second capacitors 12 and 13 by DC 300V, respectively.
A DC voltage of DC 70 KV is generated in each of the converter units 14 and 15, and an anode 18 and a cathode 1 of the X-ray tube 17 are generated.
Apply DC140KV between 9 and AC2
When the voltage is 00V, the wiring is switched to connect the first and second capacitors 12 and 13 in parallel, and the DC 300V obtained by the rectifying unit 11 is used as the first and second capacitors 1.
2 and 13, respectively, to cause the first and second DC-DC converter units 14 and 15 to generate a DC voltage of DC 70 KV, respectively, between the anode 18 and cathode 19 of the X-ray tube 17.
Since C140KV is applied, AC200 can be used without using a large step-down power transformer.
Either a V power supply or an AC 400 V power supply can be used.

Further, in this embodiment, even if the value of the DC voltage charged in the first capacitor 12 and the value of the DC voltage charged in the second capacitor 13 deviate when the power supply voltage is AC400V. The voltage correction unit 16 detects this and the first and second DC-DC converter units 1
Since the DC voltages input to 4 and 15 are balanced, even if the load of the first DC-DC converter unit 14 and the load of the second DC-DC converter unit 15 are different, these first and second DC -DC converter unit 1
It is possible to balance the values of the DC voltage output from the circuits 4 and 15.

Further, in this embodiment, the voltage shift detector 25, the step-down converter 26, the step-up converter 27 and the PWM coil 28 are used.
Since the voltage compensator 16 having a small number of components and a simple circuit configuration is used,
Even when the voltage is C400V, the power supply voltage of the entire device is AC200.
The size and weight can be substantially the same as when V is set, and thus the X-ray high-voltage power supply circuit 10 can be mounted on the gantry rotating part 9 of the gantry device 3.

[0034]

As described above, according to the power supply circuit for the X-ray high-voltage device of the present invention, it is possible to use the AC200V power supply or the AC400V power supply without using a large step-down power supply transformer or the like. . Further, in the X-ray CT apparatus of the present invention, it is not necessary to use a large step-down power supply transformer or the like even at AC400V, so that the X-ray high-voltage power supply circuit can be attached to the gantry rotating part or the like to save space. It is possible to effectively utilize the high voltage generation source and the high voltage use destination in close proximity to each other.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of an X-ray CT apparatus using an embodiment of a power supply circuit for an X-ray high voltage apparatus according to the present invention.

FIG. 2 is a circuit diagram showing a detailed configuration example of a power supply circuit for an X-ray high voltage device shown in FIG.

FIG. 3 is an AC4 circuit for the power supply circuit for the X-ray high-voltage device shown in FIG.
It is a circuit diagram which shows the structural example at the time of inputting the alternating voltage of 00V.

FIG. 4 is a typical X using a power supply voltage of AC200V.
It is a block diagram showing an example of a line high voltage device.

5 shows an AC400 with the X-ray high voltage device shown in FIG.
It is a block diagram which shows an example at the time of using the power supply voltage of V.

[Explanation of symbols]

1 X-ray CT device 2 Bed device 3 Stand device
4 image display device 5 console device 9 gantry rotating unit 10 power supply circuit for X-ray high-voltage device 11 rectifying unit 12 first capacitor 14 first DC-DC converter unit 13 second capacitor 15 second DC-DC converter unit 16 voltage correcting unit 17 X-ray tube 18 Anode 19 Cathode 20, 21, 22, 23 Diode 25 Voltage shift detector 26 Step-down converter (switching) 27 Step-up converter (switching)
28 coils

Claims (4)

[Claims] 1. A power supply circuit for an X-ray high-voltage device, which converts an AC input power supply voltage into a DC voltage and supplies the DC voltage to an X-ray tube, wherein the AC input power supply voltage is rectified to generate a DC voltage. And two capacitors connected in parallel or in series according to the value of the input power supply voltage and charged by the DC power supply voltage output from the rectification unit, and the DC voltage charged in each of the capacitors. An X-ray high-voltage device power supply circuit, comprising: two DC-DC converters that perform DC-DC conversion to generate a high-voltage DC voltage. 2. When the capacitors are connected in series and used, a DC voltage charged in each capacitor is detected when the DC voltage charged in each capacitor is unbalanced. The power supply circuit for an X-ray high-voltage device according to claim 1, further comprising a voltage correction unit that adjusts the value of. 3. The voltage correction unit detects the difference between the DC voltages charged in the capacitors, and the voltage shift detection unit detects the difference between the DC voltages. 3. A switching unit that intermittently supplies a current to the coil to generate an electromotive voltage and balances the DC voltage charged in each capacitor by the electromotive voltage. Power supply circuit for X-ray high voltage equipment. 4. An X-ray CT apparatus using the power supply circuit for an X-ray high voltage apparatus according to claim 1.