JPH07335392A - Power supply circuit for x-ray high-voltage generator, and x-ray ct device using it - Google Patents

Abstract

PURPOSE:To downsize the whole power supply circuit, and reduce the cost while preventing failure by contact abrasion when a relay is used by controlling the operation of a thyristor rectifying part by a control circuit with a simple structure. CONSTITUTION:When the charging of a capacitor 17 is started, the capacitor 17 is charged by a filament power supply voltage having a power of about several hundreds W generated by a filament current generating part 11. When the charge of the capacitor 17 is completed to some degree, this is detected by a charging state detecting part 12, and the operation of a drive part 15 is started to control a thyristor rectifying part 16. The capacitor 17 is further charged by the thyristor rectifying part 16 to supply a DC power supply voltage to a main power circuit.

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 In an X-ray CT apparatus or an X-ray diagnostic apparatus using a high voltage, a main power circuit requires an electric power of 30 KW or more. A capacitor having a capacity, for example, a capacitor having a capacity of 10,000 μF or more is arranged so that a large amount of power can be supplied.

FIG. 4 is a circuit diagram showing an example of a power supply circuit for a relay-resistance type X-ray high voltage device using such a large capacity capacitor.

Power supply circuit 1 for X-ray high-voltage device shown in this figure
01 is an inrush current prevention unit 102, a voltage input unit 103,
It is equipped with a rectifying unit 104 and a large-capacity capacitor 105, takes in a 200 VAC power supply voltage supplied from a commercial power source, etc., and charges the capacitor 105 so that an inrush current is not generated, and a DC power is supplied to the main power circuit. Supply power supply voltage.

The inrush current prevention unit 102 is the capacitor 1
When the charging of 05 is started, two relays 106 and 107 which are closed only for a predetermined period, and when each of these relays 106 and 107 are closed, 200 VAC of a commercial power source or the like is supplied. It is provided with two resistors 108 and 109 for limiting the current value of the power supply voltage, which are supplied to the rectification unit 104 while receiving the power supply voltage. Then, when the charging of the capacitor 105 is started, the relays 106 and 107 are closed only for a certain period of time, and 200 V supplied from a commercial power source or the like.
The AC power source voltage is taken in and the capacitor 1
On the other hand, the current value of the power supply voltage is limited so that no inrush current flows, and the current is supplied to the rectification unit 104.

Further, the voltage input unit 103 is provided with two relays 110 and 111 which are closed when the relays 106 and 107 of the inrush current prevention unit 102 are opened, and the capacitor 105 is After being charged to some extent, the relays 106 and 10 of the inrush current prevention unit 102 are charged.
When 7 is opened, relays 110 and 111 are closed, and 200 VA supplied from a commercial power source or the like.
The power supply voltage of C is taken in and supplied to the rectification unit 104.

The rectifying section 104 is provided with at least one rectifying diode and the like, and the inrush current preventing section 102 is provided.
Or the power supply voltage output from the voltage input unit 103 is taken in and rectified to generate a DC power supply voltage, which is supplied to the capacitor 105.

The capacitor 105 is a capacitor having a capacity capable of passing a current of 100 A or more, for example, a capacity of about 10000 μF. The capacitor 105 is charged by the DC power supply voltage output from the rectification unit 104, and a DC power supply is supplied to the main power circuit. Supply voltage.

FIG. 5 is a circuit diagram showing an example of a power supply circuit for a thyristor type X-ray high voltage device using a large capacity capacitor.

Power supply circuit 1 for X-ray high-voltage device shown in this figure
21 is a stabilized power supply unit 125 and a thyristor control unit 122.
, Thyristor rectifier 123, and large-capacity capacitor 1
24 and 20 supplied from a commercial power source, etc.
The thyristor controller 122 controls the conduction angle of the thyristor rectifier 123 so as to prevent the generation of an inrush current by taking in the power supply voltage of 0 VAC, and the capacitor 12
4 is charged and a DC power supply voltage is supplied to the main power circuit.

The stabilized power supply unit 125 is equipped with an IC circuit which takes in a power supply voltage of 200 VAC supplied from a commercial power supply or the like, or a power supply voltage obtained by transforming the power supply voltage, and generates a DC voltage of a preset voltage value. And 200V
The AC power supply voltage or a power supply voltage obtained by transforming the AC power supply voltage is taken in to stably generate a power supply voltage having a preset voltage value, and this is supplied to the thyristor control unit 122.

The thyristor control unit 122 operates based on the power supply voltage output from the stabilized power supply unit 125, and the power supply voltage input to the thyristor rectification unit 123, that is, the 200 VAC power supply voltage supplied from the commercial power supply or the like. Phase detector for detecting the phase of the
State of charge detector for detecting the state of charge of the, the trigger signal at the timing of the conduction angle at which no inrush current flows to the capacitor 124 based on the detection result of this state of charge detector and the detection result of the phase detector. It is equipped with a trigger signal generator to generate. Then, the phase of the power supply voltage input to the thyristor rectifier 123 and the degree of charging of the capacitor 124 are detected, and when the charging of the capacitor 124 is started, the conduction angle is reduced, and then the capacitor 124 is charged. A trigger signal is generated and supplied to the thyristor rectifier 123 at the timing of gradually increasing the conduction angle according to the state of charge.

The thyristor rectifying unit 123 takes in 200 VAC power supply voltage supplied from a commercial power source or the like and rectifies the four thyristors 126, 127, 128, 129.
Equipped with, 200VA supplied from commercial power source, etc.
The power supply voltage of C is taken in and the thyristor control unit 123
Each time a trigger signal is output from the thyristor 12
6 to 129, two thyristors, for example, thyristors 126, 127 or thyristors 128, 129.
To conduct. As a result, the power supply voltage is converted into a DC power supply voltage, and this is supplied to the capacitor 124.

The capacitor 124 is a capacitor having a capacity capable of passing a current of 100 A or more, for example, a capacity of about 10000 μF, and the thyristor rectifying section 123.
It is charged by the DC power supply voltage output from the device and supplies the DC power supply voltage to the main power circuit.

[0015]

By the way, in the above-mentioned power supply circuit 101 for the X-ray high voltage device of the relay / resistance system and the power supply circuit 121 for the X-ray high voltage device of the thyristor system, the following problems occur. there were.

First, the relay / resistor type X shown in FIG.
In the power supply circuit 101 for the line high-voltage device, the inrush current prevention unit 1
02 and the voltage input unit 103, a plurality of relays 106,
Since 107, 110, and 111 are used, when switching the operation modes of the inrush current prevention unit 102 and the voltage input unit 103, the relays 106, 107, 110, and 111 are used.
There is a problem that the contact state of the relays 106, 107, 110, 111 and the like must be inspected by periodical inspection or the like because the contact is worn out after a certain number of times of use as well as the switching sound of. .

Further, a plurality of relays 106, 107, 11
Since 0 and 111 are used, there is a problem that the entire power supply circuit becomes large and the space factor is not good.

Further, in the power supply circuit 121 for the X-ray high-voltage device of the thyristor system shown in FIG. 5, each of the thyristors 126 to 129 forming the thyristor rectifying section 123 is maintained for a certain period after the charging of the capacitor 124 is started. Of the thyristors 126 to 129 is set to 100% after the charging of the capacitors 124 is completed to some extent, so that the conduction angle of each of the thyristors 126 is reduced to 100%. ~ 129
Therefore, after the initial charging of the capacitor 124 is completed, the thyristor control unit 122 becomes unnecessary.

Therefore, at the time of high voltage output operation, the thyristor controller 122, which becomes unnecessary, is provided.
There is a problem that the cost becomes high and the entire power supply circuit becomes large.

In view of the above-mentioned circumstances, the present invention can control the operation of the thyristor rectification unit by the control unit having a simple structure, thereby preventing the occurrence of failure due to contact wear when the relay is used. An object of the present invention is to provide a power supply circuit for an X-ray high-voltage device that can reduce the size and cost of the entire power supply circuit and an X-ray CT device using the same.

[0021]

In order to achieve the above object, the power supply circuit for an X-ray high-voltage device according to the first invention of the present application charges a large-capacity capacitor by rectifying an AC input power supply voltage by a thyristor rectifier. In a power supply circuit for an X-ray high voltage device that outputs a DC power supply voltage, a small capacity power supply unit that generates a DC power supply voltage of small capacity power to charge the large capacity capacitor, and a charge amount of the large capacity capacitor. When the voltage exceeds a desired set value, thyristor control for detecting this and turning on / off each thyristor of the thyristor rectifying unit according to the phase of the input power supply voltage to charge the large-capacity capacitor It is characterized by having a section.

In the power supply circuit for the X-ray high-voltage device according to the second aspect of the present invention, the AC input power supply voltage is rectified by the thyristor rectifier to charge the large-capacity capacitor and the DC power supply voltage is output. In a power supply circuit for a line high-voltage device, a small-capacity power supply unit that generates a direct-current power supply voltage of small-capacity power to charge the large-capacity capacitor, and a constant voltage diode to charge the large-capacity capacitor to a desired set value or more. When this occurs, it detects this, and detects the phase of the input power supply voltage input to the thyristor rectifier by the charge state detector that outputs the detection result with an optical signal and the diode bridge circuit. A phase detection section that outputs the detection result, a photo detection element that is conductive when receiving the optical signal output from the charge state detection section, and an optical signal output from the phase detection section When it is detected that the amount of charge of the large-capacity capacitor is equal to or higher than a desired set value by the photodetector element that receives and conducts, each thyristor of the thyristor rectifier is turned on according to the phase of the input power supply voltage. A drive unit that is turned on / off to charge the large-capacity capacitor.

Further, the X-ray CT apparatus according to the third invention of the present application is characterized in that the power supply circuit for the X-ray high-voltage apparatus according to the first or second invention is arranged in the gantry rotating section.

[0024]

The X according to the first invention of the present application constructed as described above
In the power supply circuit for line high-voltage devices, a small-capacity power supply unit generates a small-capacity direct-current power supply voltage to charge a large-capacity capacitor, and the charge amount of this large-capacity capacitor exceeds a preset value. At this time, by detecting this by the thyristor control unit, turning on / off each thyristor of the thyristor rectifying unit according to the phase of the input power supply voltage, and charging the large-capacity capacitor, a simple configuration is realized. The operation of the thyristor rectifier is controlled by the control circuit, thereby preventing the occurrence of a failure due to contact wear when the relay is used, while reducing the size and cost of the entire power supply circuit.

Further, in the power supply circuit for the X-ray high-voltage device according to the second aspect of the invention, the small capacity power supply section generates a DC power supply voltage of small capacity power to charge the large capacity capacitor, and further the diode of the phase detection section. While detecting the phase of the input power supply voltage input to the thyristor rectifier by the bridge circuit, when the charge amount of the large-capacity capacitor is equal to or more than a preset value, the constant voltage diode of the charge state detector detects This is detected, and when the charge state detection unit detects that the amount of charge of the large-capacity capacitor is equal to or greater than a preset value, it is detected by each photodetection element of the drive unit. The thyristor of the thyristor rectifier is turned on / off according to the phase of the input power supply voltage based on the detection result of the phase detector.
By turning off and charging the large-capacity capacitor, the operation of the thyristor rectifier is controlled by the control circuit having the same simple structure as in the first aspect of the invention, which causes contact wear when a relay is used. The size and cost of the entire power supply circuit are reduced while preventing the occurrence of failures.

Further, in the X-ray CT apparatus according to the third invention, the power supply circuit for the X-ray high-voltage apparatus according to the first or second invention is arranged in the gantry rotating part, so that the X-ray high-voltage apparatus can be used. Improves the space factor when mounting the power supply circuit on the gantry rotating part, etc., and also prevents noise from being applied to other devices placed on the gantry rotating part, thereby reducing the size and reliability of the entire device. Improve sex.

[0027]

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 this figure has a bed apparatus 2 on which a patient to be examined is placed, a gantry rotating unit 9 and a power supply circuit 10 for the X-ray high-voltage apparatus. The gantry device 3 that collects X-ray data while irradiating X-rays to the patient placed on the top plate of No. 2, and the gantry device 3 and the gantry device 3 based on the operation content of the doctor (or technician). The couch device 2 is controlled, and 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 it on the image display device 4 is provided. ing.

The patient to be examined is placed on the bed device 2
After adjusting the height and position of the patient placed on the bed apparatus 2 based on the operation contents of the operation console apparatus 5, the pedestal apparatus 3 having a hole formed in the central portion X-rays are emitted from 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. It is displayed on the image display device 4 of the console device 5.

After that, of the X-ray cross-sectional images displayed on the image display device 4, the X-ray cross-sectional images necessary for diagnosis are transferred to an imager device (not shown) and printed on a film. Let the doctor use it for diagnosis.

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. 3, the filament current generator 11, the charge state detector 12, the drive voltage generator 13, and the phase detector 1
4, a drive unit 15, a thyristor rectifying unit 16, and a large-capacity capacitor 17 are provided.
When the charging of the capacitor 17 is started, the capacitor 17 is charged with the filament power supply voltage having the electric power of about several hundred W generated by the filament current generator 11, and when the charging of the capacitor 17 is completed to some extent, the charge state detector This is detected by 12, the operation of the drive unit 15 is started, and the thyristor rectification unit 16 is controlled,
The thyristor rectifier 16 further charges the capacitor 17 to supply a DC power supply voltage to the main power circuit.

The filament current generator 11 has at least one diode having a current capacity of about several amperes, and takes in a single-phase 200 VAC power supply voltage supplied from a commercial power source or the like and rectifies it, and this rectification. A small-capacity capacitor 19 for smoothing the DC power supply voltage obtained by the unit 18, and a DC power supply voltage (filament power supply voltage) smoothed by the capacitor 19 are supplied to the capacitor 17 while limiting the current value thereof. , Two resistors to charge this (a resistor with a value of about 100Ω) 2
0 and 21 are provided, and the power supply voltage of single-phase 200 VAC supplied from a commercial power supply or the like is taken in and rectified,
A filament power supply voltage having a power of about several hundred W is generated by smoothing and is supplied to the filament such as a tube and is supplied to the capacitor 17 to be charged.

Further, the drive voltage generator 13 takes in a single-phase 200 VAC power supply voltage supplied from a commercial power supply or the like and transforms it into a drive power supply voltage, for example, 10 V, which is necessary to bring the thyristors 40 and 41 into conduction. 22, a rectifying unit 23 having at least one diode, which rectifies the drive power supply voltage output from the transformer 22 to generate a DC drive power supply voltage, and a DC drive power supply output from the rectifying unit 23. It has a small-capacity capacitor 24 for smoothing the voltage and takes in a power supply voltage of a single-phase 200 VAC supplied from a commercial power supply or the like, transforms it, and drives the thyristors 40 and 41 to the extent necessary for conduction. After generating the power supply voltage,
This is rectified and smoothed to form a DC drive power supply voltage, which is supplied to the drive unit 15. In addition, the transformer 2
2 is an existing transformer in the gantry device 3, 10V,
Since a tap having an output capacity of about 0.1 A is added, the entire circuit can be accommodated with a margin in the space prepared for the power supply circuit 10 for the X-ray high-voltage device. .

When the charging of the capacitor 17 is started and the value of the DC power supply voltage charged in the capacitor 17 is equal to or higher than a preset value (zener voltage), the charging state detecting section 12 starts charging. The constant voltage diode 25 that conducts, the resistor 26 that limits the current value when the constant voltage diode 25 is conductive, and the operation of the drive unit 15 by emitting light when the constant voltage diode 25 is conductive. Light-emitting diode 2 for optical coupling to start
7, the charging of the capacitor 17 is started, and when the value of the DC power supply voltage charged in the capacitor 17 exceeds a preset value by this charging operation, the constant voltage diode 25 When this is detected, the light emitting diode 27 is caused to emit light to generate an optical drive-on signal, and the optical drive-on signal is generated.
Supply to.

Further, in the phase detector 14, the power supply voltage input to the thyristor rectifier 16, that is, the power supply voltage of single-phase 200 VAC supplied from a commercial power supply or the like has a preset polarity, for example, positive polarity. Two diodes 28 and 29 which are conductive when they are on, a light-emitting diode 30 for light coupling which emits light when these diodes 28 and 29 are on, and the single-phase 200 VA
Two diodes 3 which become conductive when the power supply voltage of C has a preset polarity, for example, negative polarity
1, 32, a light emitting diode 33 for optical coupling that emits light when these diodes 31, 32 are in a conductive state, and a resistor 34 that serves as a current route when each of the light emitting diodes 30, 33 emits light. It has and.

Then, when the power supply voltage of the single-phase 200 VAC supplied from the commercial power supply or the like switches from the negative polarity to the positive polarity, among the diodes 28, 29, 31, 32,
One of the diodes 28 and 29 is turned on to cause the light emitting diode 30 to emit light, and the optical trigger signal obtained thereby is supplied to the drive unit 15. Also, the single phase 200
When the power supply voltage of the VAC is switched from the positive polarity to the negative polarity, the other diode 31, 32 among the diodes 28, 29, 31, 32 becomes conductive, and the light emitting diode 33.
Is emitted and the optical trigger signal obtained thereby is supplied to the drive unit 15.

The drive unit 15 includes the charge state detection unit 12
When an optical drive-on signal is output from the phototransistor 35, the phototransistor 35 is turned on to capture and output the drive power supply voltage output from the drive voltage generation unit 13.
When the photo-transistor 35 outputs the drive power supply voltage and one light-emitting diode 30 provided in the phase detector 14 outputs an optical trigger signal, the photo-transistor 35 conducts to generate a trigger signal. Phototransistor 36 and this phototransistor 3
The resistor 37 supplied to the thyristor rectifier 16 while limiting the current value of the trigger signal output from the transistor 6 and the phase detector 14 provided with the drive power supply voltage output from the phototransistor 35. A phototransistor 38 that conducts when an optical trigger signal is being output from the other light emitting diode 33 that is generating a trigger signal, and the thyristor rectifying unit that limits the current value of the trigger signal output from the phototransistor 38. 16 and a resistor 39 that supplies the voltage to the resistor 16.

Then, when the optical drive-on signal is output from the charge state detecting section 12, the phototransistor 35 becomes conductive, and the drive power supply voltage output from the drive voltage generating section 13 is taken in and each phototransistor is taken. 36, 38, and when a light trigger signal is output from one light emitting diode 30 provided in the phase detector 14 in this state, one phototransistor 36 conducts to generate a trigger signal. Is supplied to the thyristor rectification unit 16. Further, when a light trigger signal is output from the other light emitting diode 33 provided in the phase detector 14, the other phototransistor 38 is turned on to generate a trigger signal, which is supplied to the thyristor rectifier 16. To do.

In this case, when one of the two phototransistors 36 and 38 provided in the drive section 15 is turned on, the other is turned off, so that the power of the drive voltage generation section 13 is reduced. Capacity is 100m
W is enough.

The thyristor rectifying section 16 takes in two thyristors 40 and 41 for taking in and rectifying a single-phase 200 VAC power source voltage supplied from a commercial power source, and two thyristors 40 and 41 respectively connected to the thyristors 40 and 41. One thyristor 40, 41 and one diode for each trigger signal output from the drive unit 15 that takes in a single-phase 200 VAC power supply voltage supplied from a commercial power source or the like. Diode 42,
The corresponding one of 43 is conductive, converts the power supply voltage into a DC power supply voltage, and supplies this to the capacitor 17.

The capacitor 17 is a capacitor having a capacity capable of flowing a current of 100 A or more, for example, a capacity of about 10000 μF, and is charged by the filament power supply voltage output from the filament current generator 11 in the initial state of charging. After that, when the charging is completed to some extent, it is further charged by the DC power supply voltage output from the thyristor rectifying unit 16, and the DC power supply voltage stored by these charging operations is supplied to the main power circuit.

As described above, in this embodiment, when the charging of the capacitor 17 is started, the capacitor 17 is charged with the filament power supply voltage generated by the filament current generating unit 11 and having a power of about several hundred W.
When the charging of the capacitor 17 is completed to some extent,
The charge state detection unit 12 detects this, starts the operation of the drive unit 15 and controls the thyristor rectification unit 16, and the thyristor rectification unit 16 controls the capacitor 1
7 is further charged to supply the DC power supply voltage to the main power circuit. Therefore, the charge state detection unit 12, the drive voltage generation unit 13, the phase detection unit 14 and the drive unit 1
The operation of the thyristor rectification unit 16 can be controlled by a control circuit having a simple structure constituted by 5, and for this purpose it is possible to prevent the occurrence of a failure due to contact wear when a relay is used and for an X-ray high-voltage device. Power supply circuit 10
The overall size and cost can be reduced.

Further, in this embodiment, the power supply circuit 10 for the X-ray high-voltage device can be downsized and the cost thereof can be reduced. Therefore, this is mounted on the gantry rotating part 9 of the continuous rotation type X-ray CT device 1. In this case, the space factor can be improved, and since the thyristors 40 and 41 in the power supply circuit 10 for the X-ray high-voltage device are not phase-controlled, phase noise is prevented from occurring and the gantry rotating part 9 is prevented.
It is possible to prevent adverse effects on peripheral devices arranged in the.

In the above-mentioned embodiment, the single phase 2
Although the capacitor 17 is charged by taking in the power source voltage of 00 VAC, the capacitor 17 may be charged by taking in the power source voltage of three-phase 200 VAC.

FIG. 3 is a circuit diagram showing an example of a power supply circuit for an X-ray high voltage device which takes in such a power supply voltage of three-phase 200 VAC and charges a large capacity capacitor. In this figure, the same parts as those in FIG. 1 are designated by the same reference numerals.

Power supply circuit 1 for X-ray high-voltage device shown in this figure
0 is different from the circuit shown in FIG.
The drive unit 15 and the thyristor rectifying unit 16 are respectively 3
Three-phase 200 supplied from a commercial power source in phase format
That is, the power supply voltage of VAC is taken in and the capacitor 17 is charged.

In the phase detector 14, the power supply voltage input to the thyristor rectifier 16, that is, the T-phase power supply voltage of three-phase 200 VAC supplied from a commercial power supply or the like has a preset polarity, for example, positive polarity. A diode 50 which becomes conductive when the diode 50 is in a conductive state, a light-emitting diode 52 for optical coupling which emits light when the diode 50 is in a conductive state, and a polarity in which the U-phase power supply voltage of the three-phase 200 VAC is preset. For example, when the diode 53 has a positive polarity, the diode 53 which is in a conductive state, the light-emitting diode 55 for optical coupling which emits light when the diode 53 is in a conductive state, and the V-phase power supply voltage of the three-phase 200 VAC are previously set. A diode 56 that is in a conductive state when the polarity is set, for example, a positive polarity, and the diode 56 is in a conductive state. When going on, the light emitting diode 58 for optical coupling to the light emitting, the diodes 50, 5
A plurality of diodes 5 that are conductive so as to correspond to 3, 56
1, 54, 57 and the light emitting diodes 52, 55,
The resistor 59 serves as a current route when 58 emits light.

Then, when the T-phase power supply voltage constituting the power supply voltage of three-phase 200 VAC supplied from the commercial power supply or the like switches from the negative polarity to the positive polarity, the respective diodes 50, 5
Of the elements 3, 56, the T-phase diode 50 and the diodes 51, 54 corresponding to the diode 50 are rendered conductive, and
The light emitting diode 52 of the phase is caused to emit light to generate an optical trigger signal, which is supplied to the drive unit 15. Next, when the U-phase power supply voltage constituting the power supply voltage of the three-phase 200 VAC is switched from the negative polarity to the positive polarity, each diode 5
Of 0, 53, and 56, the U-phase diode 53 and the diodes 51 and 57 corresponding to the diode 53 are turned on to cause the U-phase light-emitting diode 55 to emit light and generate an optical trigger signal, which is sent to the drive unit 15. Supply. Next, when the V-phase power source voltage constituting the three-phase 200 VAC power source voltage is switched from the negative polarity to the positive polarity, the V-phase diode 56 among the respective diodes 50, 53, 56 and the diode 54 corresponding to the diode 56, 57
Is turned on, the V-phase light emitting diode 58 is caused to emit light, and an optical trigger signal is generated and supplied to the drive unit 15.

The drive unit 15 conducts when the optical drive-on signal is output from the charge state detection unit 12 and takes in the drive power supply voltage output from the drive voltage generation unit 13 and outputs the phototransistor 60. In the state where the drive power supply voltage is output from the transistor 60, the T
The phototransistor 61 that conducts when a light trigger signal is output from the phase light emitting diode 52 to generate a trigger signal, and the thyristor rectifying unit 16 while limiting the current value of the trigger signal output from the phototransistor 61. When the optical trigger signal is output from the U-phase light emitting diode 55 provided in the phase detection unit 14 while the drive power supply voltage is being output from the resistor 62 that is supplied to Phototransistor 6 that generates a trigger signal
3, a resistor 64 supplied to the thyristor rectifier 16 while limiting the current value of the trigger signal output from the phototransistor 63, and the phototransistor 6
In the state where the drive power supply voltage is output from 0, the V-phase light emitting diode 5 provided in the phase detection unit 14
When the optical trigger signal is output from 8, the phototransistor 65 that conducts to generate the trigger signal and the current value of the trigger signal output from the phototransistor 65 are supplied to the thyristor rectifying unit 16 while limiting the current value. And a resistor 66.

When the optical drive-on signal is output from the charge state detecting section 12, the phototransistor 60 is turned on, and the drive power supply voltage output from the drive voltage generating section 13 is taken into each phototransistor. 61, 63, 65, and in this state, the T-phase light-emitting diode 5 provided in the phase detector 14
When an optical trigger signal is output from 2, the T-phase phototransistor 61 is turned on to generate a trigger signal, which is supplied to the thyristor rectifier 16. Next, the U-phase light emitting diode 55 provided in the phase detector 14
When the optical trigger signal is output from the U-phase phototransistor 63, the U-phase phototransistor 63 is turned on to generate a trigger signal, which is supplied to the thyristor rectifier 16. Next, the V-phase light-emitting diode 5 provided in the phase detector 14
When an optical trigger signal is output from 8, the V-phase phototransistor 65 is turned on to generate a trigger signal, which is supplied to the thyristor rectifier 16.

In this case, the T-phase, U-phase, and V-phase phototransistors 61 and 6 provided in the drive section 15 are provided.
When one of the elements 3 and 65 is turned on, the rest is turned off, so that the power capacity of the drive voltage generator 13 can be set to about 100 mW as in the above-described embodiment.

The thyristor rectifying unit 16 is connected to the three thyristors 67, 68, 69 for taking in and rectifying the power supply voltage of three-phase 200 VAC supplied from a commercial power source and the thyristors 67, 68, 69, respectively. It is equipped with three diodes 70, 71, 72 which are provided, and take in the power supply voltage of three-phase 200 VAC supplied from a commercial power supply or the like, and each of the T-phase, U-phase and V-phase trigger signals from the drive unit 15 is supplied. Each time it is output, T-phase, U-phase, and V-phase thyristors 67, 68, 69 and diodes 70, 71 corresponding to these thyristors 67, 68, 69,
Two 72 are sequentially turned on to convert the power supply voltage of the three-phase 200 VAC into a DC power supply voltage, and the DC power supply voltage is supplied to the capacitor 17.

As described above, in this embodiment, when the charging of the capacitor 17 is started, the capacitor 17 is charged with the filament power supply voltage having a power of about several hundred W generated by the filament current generator 11.
When the charging of the capacitor 17 is completed to some extent, the charge state detection unit 12 detects this and the drive unit 15
To control the thyristor rectifier 16 and
Since the capacitor 17 is further charged by the thyristor rectification unit 16 to supply the DC power supply voltage to the main power circuit, the charge state detection unit 12, the drive voltage generation unit 13, and the phase detection unit are similar to the above-described embodiment. The operation of the thyristor rectification unit 16 can be controlled by a control circuit having a simple configuration configured by the drive unit 14 and the drive unit 15. While preventing the occurrence of failure due to contact wear when the relay is used, The power supply circuit 10 for the X-ray high-voltage device can be reduced in size and cost as a whole.

[0054]

As described above, according to the power supply circuit for the X-ray high-voltage device of the present invention, the operation of the thyristor rectifier can be controlled by the control circuit having a simple structure, and the relay can be used. It is possible to reduce the size and cost of the entire power supply circuit while preventing the occurrence of failure due to contact wear or the like. In addition, in the X-ray CT apparatus of the present invention, it is possible to improve the space factor when mounting the power supply circuit for the X-ray high-voltage device on the gantry rotating section, and at the same time, to install another apparatus arranged on the gantry rotating section. However, it is possible to prevent noise from being applied to the device, which makes it possible to reduce the size of the entire device and improve reliability.

[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 circuit configuration example of the power supply circuit for the X-ray high-voltage device shown in FIG.

FIG. 3 is a circuit diagram showing another embodiment of a power supply circuit for an X-ray high voltage device according to the present invention.

FIG. 4 is a circuit diagram showing an example of a power supply circuit for a relay-resistance type X-ray high-voltage device, which has been used conventionally and which uses a large-capacity capacitor.

FIG. 5 is a circuit diagram showing an example of a conventional power supply circuit for a thyristor type X-ray high-voltage device using a large-capacity capacitor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 X-ray CT device 2 Bed device 3 Mounting device 4 Image display device 5 Operating console device 9 Mounting device rotating part 10 Power supply circuit for X-ray high-voltage device 11 Filament current generation part (small capacity power supply part) 12 Charge state detection part (charging) State detection section) 13 Drive voltage generation section 14 Phase detection section 15 Drive section (thyristor control section) 16 Thyristor rectification section 17 Large capacity capacitor (large capacity capacitor) 18 Rectification section 19 Small capacity capacitor 20,
21 resistance 22 transformer 23 rectifier 24 small capacity capacitor 25 constant voltage diode 26 resistance 27 light emitting diode 28, 29 diode (diode bridge circuit) 30, 33 light emitting diode 31, 32 diode (diode bridge circuit) 34, 37, 39 resistance 35, 36, 38 Phototransistor (photodetector) 40, 41 Thyristor 42, 43 Diode

Claims (3)

[Claims] 1. A power supply circuit for an X-ray high-voltage device that rectifies an AC input power supply voltage by a thyristor rectifier to charge a large-capacity capacitor and outputs a DC power supply voltage. A small-capacity power supply unit that generates and charges the large-capacity capacitor, and when the amount of charge of the large-capacity capacitor is equal to or greater than a desired set value, this is detected, and according to the phase of the input power-supply voltage, A power supply circuit for an X-ray high-voltage device, comprising: a thyristor control unit that turns on / off each thyristor of the thyristor rectification unit to charge the large-capacity capacitor. 2. A power supply circuit for an X-ray high-voltage device, which rectifies an AC input power supply voltage by a thyristor rectifier to charge a large-capacity capacitor and outputs a DC power supply voltage. A small-capacity power supply unit that generates and charges the large-capacity capacitor, and a constant voltage diode detects this when the charging amount of the large-capacity capacitor exceeds a desired set value, and the detection result is an optical signal. A state of charge detecting section that outputs a phase detection section that detects the phase of the input power supply voltage that is input to the thyristor rectifying section by a diode bridge circuit, and outputs the detection result as an optical signal, and from the state of charge detecting section The large-capacity capacitor is configured by a photodetector element that is conductive when receiving an output optical signal and a photodetector element that is conductive when receiving an optical signal output from the phase detector. When it is detected that the charge amount of the capacitor exceeds a desired set value, each thyristor of the thyristor rectifying unit is turned on / off according to the phase of the input power supply voltage, and the large-capacity capacitor is turned on. A power supply circuit for an X-ray high-voltage device, comprising: a drive unit that charges the battery. 3. An X-ray CT apparatus, wherein the X-ray high-voltage power supply circuit according to claim 1 is arranged in a gantry rotating part.