KR20110012585A - Boost rectifier of power supply for x-ray generator - Google Patents

Abstract

PURPOSE: A boost rectifier of a power supply device for an X-ray generator is provided to obtain an X-ray waveform of high quality by arranging condensers with different capacities on a plurality of voltage doubling stages. CONSTITUTION: A boost rectifier(215) includes a positive rectifier and a negative rectifier. The positive rectifier supplies the boosted voltage to the positive terminal of an X-ray tube(216) after the positive rectifier boosts the voltage induced to the secondary side of a transformer to the high voltage of N times. N voltage doubling states of the positive rectifier include a positive condenser, a positive diode group, a negative condenser, and a negative diode group. The negative rectifier supplies the boosted voltage to the negative terminal of the X-ray tube after the voltage induced to the secondary side of the transformer is boosted to the high voltage of N times.

Description

Boost rectifier of power supply for x-ray generator

The present invention relates to a step-up rectifier of a power supply for an x-ray generator.

In general, an X-ray photographing apparatus uses X-rays having different transmittances depending on materials to show differences in transmittance between various organs in the human body as X-ray images (images of shadows in which various structures in the human body are projected onto a film). In addition to the diagnosis of various organs and lungs, it is used for non-destructive testing to find defects in structures.

In recent years, portable X-ray photographing apparatuses have been developed, and these small X-ray photographing apparatuses can generate X-rays even at a relatively low 70 KV voltage, thereby enabling the production of miniaturized portable photographing apparatuses.

In other words, since a huge amount of energy is required at the time of X-ray irradiation, a power supply device capable of providing such a large amount of energy is required, and a power supply device capable of obtaining a high voltage even at a low voltage has been developed and used.

1 is an exemplary view for explaining the principle of obtaining a high voltage of the power supply device according to the prior art.

As shown in FIG. 1, as a boost rectification unit in a power supply according to the prior art, the boost rectification unit obtains a high voltage by using a plurality of diodes and a capacitor.

In other words, when a negative AC pulse voltage is applied to the secondary side of the transformer, a closed circuit of the capacitor C1 and the diode D1 is configured to accumulate the secondary voltage of the transformer to the capacitor C1, and a positive AC pulse voltage is applied to the capacitor C1. The closed circuit of the capacitor C1, the diode D3, and the capacitor C4 is configured so that the voltage stored in the capacitor C1 and the secondary voltage of the transformer are accumulated in the capacitor C4.

In this way, voltages are accumulated in the capacitors C2, C5, C3, and C6 in sequence. A high voltage corresponding to six times the voltage stored in the capacitor C1 is accumulated in the capacitor C6 of the final stage, and the accumulated high voltage is stored in the X-ray tube. To be authorized.

However, at the moment when the AC pulse voltage of the transformer is applied, the voltage is accumulated in the capacitor of each stage, but the voltage is not accumulated in the capacitor of each stage during the off time when the AC pulse voltage of the transformer is not applied. Since the discharge to supply the load power, the DC voltage of the final stage has a voltage ripple by the switching frequency.

The smaller the voltage ripple, the better the quality of the x-rays coming out of the x-ray dube of the output stage. Therefore, it is necessary to reduce the voltage ripple. However, in order to reduce such voltage ripple, the switching frequency of the primary side of the transformer must be increased. However, the design of the product has a problem of increasing the switching frequency.

The present invention is to solve the problems of the prior art as described above, by using a full-wave rectification method to configure the boost rectification unit, by configuring the capacity of the capacitor for each back pressure stage different, it is possible to reduce the tube voltage ripple in the X-ray tube To provide a step-up rectifier of a power supply for an x-ray generator.

The present invention provides a boosting rectifying unit of a power supply device for an X-ray generator, by using a full-wave rectifying method to configure a boosting rectifying unit, and having a different capacitance of each back pressure stage to obtain a high quality X-ray waveform. .

In addition, the present invention provides a boosting rectifying unit of the power supply device for the X-ray generator to improve the reliability of the product by configuring the boosting rectifying unit using a full-wave rectification method, by configuring the capacity of the capacitor in each back pressure stage differently. It is.

To this end, the step-up rectifier of the power supply device for the x-ray generator according to an aspect of the present invention is connected to the N side of the back of the transformer for controlling the tube voltage in series, the voltage induced in the secondary side of the transformer (+) Side rectifier for boosting the voltage to N times the high voltage to provide the (+) side terminal of the X-ray tube; And N back pressure stages are connected in series to the secondary side of the transformer to boost the voltage at the secondary side of the transformer to a N-times high voltage to provide a negative terminal to the negative terminal of the X-ray tube. It may be characterized by including a rectifying unit.

Preferably, the N back pressure stages of the (+) side rectifier may include: (+) capacitors that accumulate voltage when a negative AC pulse voltage is applied to the secondary side of the transformer; (+) Diode group connected in parallel to the (+) capacitor; A negative capacitor accumulating the voltage when a positive AC pulse voltage is applied; And a (-) side diode group connected in parallel to the (-) side capacitor on the secondary side of the transformer.

The (+) side diode group is two diodes connected in series, and at least two (+) side diodes connected in parallel to the (+) side capacitor in the first back pressure stage among the back pressure stages connected in series with the secondary side of the transformer. It can include a group.

The (-) side diode group is two diodes connected in series, and the first back stage among the back stages connected in series with the secondary side of the transformer is at least two (-) side diodes connected in parallel to the (-) side capacitor. It can include a group.

Preferably, the N back pressure stages of the (+) side rectifiers have (7-N) (+) side capacitors connected in parallel, and (7-N) (-) sides connected in parallel with different capacitor capacities. It may be characterized by including a capacitor, respectively. And the N back pressure stages of the (-) side rectifier may include (7-N) (+) side capacitors connected in parallel with different capacitor capacities; And (7-N) (-) side capacitors connected in parallel, respectively.

Preferably, the N back pressure stages of the (-) side rectifier may include: (+) side capacitors that accumulate voltage when a negative AC pulse voltage is applied to the secondary side of the transformer; (+) Diode group connected in parallel to the (+) capacitor; A negative capacitor accumulating the voltage when a positive AC pulse voltage is applied; And a (-) side diode group connected in parallel to the (-) side capacitor on the secondary side of the transformer.

When a negative (-) or (+) AC pulse voltage is applied, an N-fold voltage may be accumulated in each of the (+) side capacitor and the (-) side capacitor of the Nth back pressure stage connected in series with the secondary side of the transformer. .

Hereinafter, the step-up rectifier of the power supply device for the x-ray generator according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 3. That is, the present invention comprises a boost rectification unit in the power supply device for the x-ray generator using a full-wave rectification method or onion rectification method to achieve the same effect as to increase the switching frequency twice, for each back pressure stage in the boost rectification unit The capacity of the capacitor is to be configured differently.

2 is an exemplary view showing the configuration of a power supply for an x-ray generator according to an embodiment of the present invention.

As shown in FIG. 2, a power supply device for an X-ray generator according to an embodiment of the present invention includes an AC power supply unit 201, a charger 202, a PCM board 203, a lithium polymer battery 204, and a power control unit. 205, sequence control unit 206, PWM IC 207 for tube voltage control, PWM IC 208 for tube current control, switching elements 209 and 210 for tube voltage control, switching elements 211 and 212 for tube current control, transformer for tube voltage control 213, a filament control transformer 214, a boost rectifier 215, an x-ray tube 216, a tube voltage detector 217, a tube current detector 218, and the like.

Referring to the operation of the power supply for the X-ray generator is configured as follows.

That is, the AC power supplied from the AC power supply unit 100 may be charged in the lithium polymer battery 140 connected to the AC power source after passing through the PCM board 130 through the charger 2. The voltage of the lithium polymer battery 4 may be applied to both ends of the tube voltage control switching elements 190 and 200 and the filament control switching elements 210 and 220 by the sequence control unit 6 connected to the power control unit 5, respectively. have.

At this time, when a predetermined switch for irradiating the X-ray from the user using the X-ray imaging apparatus is pressed, the sequence control unit 160 determines the tube voltage DC command value and tube current DC command value suitable for the X-ray irradiation condition set from the outside to determine the PWM voltage for tube voltage control ( 170) and the tube current control PWM IC 180, respectively.

In addition, the tube voltage control PWM IC 170 receives the tube voltage DC command value and the output of the tube voltage detector 270 and inputs the output determined based on the tube voltage to the gates of the corresponding tube voltage control switching elements 190 and 200 to control the tube voltage control transformer 230. The voltage generated on the primary side of the c) and induced on the secondary side may be boosted to high pressure by the boost rectifying unit 250, rectified by DC, and applied to the X-ray tube 260.

In addition, the tube current control PWM IC 180 receives the output of the tube current DC command value and the tube current detector 280 and inputs the output determined based on this to the gate of the corresponding tube current control switching elements 210 and 220, thereby controlling the filament control transformer ( 240) The primary side voltage is generated, and the coil of the X-ray tube 260 is heated by the voltage induced on the secondary side.

3 is an exemplary view showing a detailed configuration of the boost rectifying unit 215 shown in FIG.

As shown in FIG. 3, the boost rectifier 215 in the power supply device according to the present invention boosts the voltage induced on the secondary side of the tube voltage control transformer to a high voltage and provides it to the (+) side terminal of the X-ray tube. ) And a (-) side rectifier for providing a voltage to the (-) side terminal of the X-ray tube.

First, the (+) rectifier has N back pressure stages connected in series to the secondary side of the transformer for controlling the tube voltage, and boosts the voltage induced on the secondary side of the transformer to N times the high voltage, thereby increasing the (+) Can be provided to the side terminal.

Each of the N back pressure stages of the (+) rectifier is connected in parallel to the (+) capacitor and (+) capacitor which accumulate the voltage when a negative AC pulse voltage is applied to the secondary side of the transformer. A) side diode group, a (-) side capacitor that accumulates voltage when a positive (+) AC pulse voltage is applied, and a (-) side diode group connected in parallel to the (-) side capacitor on the secondary side of the transformer It may include.

At this time, the (+) side diode group is two diodes connected in series, and the first one of the back pressure stages connected in series with the transformer withstands damage of components due to inrush current during initial charging. And at least two (+) side diode groups connected in parallel to the (+) side capacitors.

In particular, the N back pressure stages of the (+) rectifier according to the present invention have (7-N) (+) side capacitors connected in parallel with different capacitor capacities so as to further reduce the tube voltage ripple during charging, and It can be configured to include each (7-N) (-) side capacitors connected in parallel.

For example, six (+) side capacitors and (-) side capacitors are connected in parallel to the first back pressure stage, and five (+) side capacitors and (-) side capacitors are connected in parallel to the second back pressure stage, respectively. Four (+) side capacitors and (-) side capacitors are connected in parallel to the third back pressure stage, and three (+) side capacitors and (-) side capacitors are connected in parallel to the fourth back pressure stage. Two (+) side capacitors and (-) side capacitors are connected in parallel to the back pressure stage, and one (+) side capacitor and (-) side capacitor are respectively connected in parallel to the sixth back pressure stage.

In addition, the (-) side diode group is two diodes connected in series, and the first one of the back pressure stages connected in series with the secondary side of the transformer can withstand the damage of the component due to inrush current during initial charging. It may be configured to include at least two (-) side diode groups connected in parallel to the (-) side capacitor.

In this case, the contacts between the two diodes in the (+) side diode group of each back pressure stage and the contacts between the two diodes in the (−) side diode group may be connected to each other.

Referring to the principle that the voltage is accumulated in each capacitor according to this configuration as follows.

For example, if a negative AC pulse voltage is applied to the secondary side of the transformer, a closed circuit of the capacitors C73, diodes D23, D22 is configured to accumulate the secondary voltage of the transformer on the capacitor C73, and a positive AC pulse voltage is generated. When applied, the closed circuits of the capacitors C74, diodes D24, and D21 are configured so that the secondary voltage of the transformer is accumulated in the capacitor C74.

Next, when a negative AC pulse voltage is applied to the secondary side of the transformer, a closed circuit of capacitors C73, C78, diodes D43, D25, and capacitor C74 is formed, and the voltage accumulated in capacitor C74 and capacitor secondary voltage of capacitor C78 is formed. When a positive AC pulse voltage is applied, a closed circuit of capacitors C74, C80, diodes D44, D26, and capacitor C73 is configured to accumulate the voltage accumulated in capacitor 73 and the secondary voltage of the transformer in capacitor C80. do.

In this manner, alternating pulse voltages of (-) and (+) are applied alternately to accumulate voltages in the capacitors C79, C81, C92, C94, C93, C95, C97, and C96 in order. The high voltage corresponding to six times the voltage accumulated in C74 is accumulated, and the accumulated high voltage is applied to the positive terminal of the X-ray tube. In the capacitor C96, a high voltage corresponding to six times the voltage stored in the capacitor C73 is accumulated, and the accumulated high voltage is applied to the negative terminal of the X-ray tube.

In addition, the (-) side rectifying unit has N back pressure stages connected in series to the secondary side of the transformer for controlling the tube voltage, and boosts the voltage induced on the secondary side of the transformer to N times the high voltage so that the (-) Can be provided to the side terminal.

The N back pressure stages of the (-) rectifier are connected to the (+) capacitor and (+) capacitor connected in parallel to accumulate the voltage when a negative AC pulse voltage is applied to the secondary side of the transformer. The negative diode group, the negative (+) capacitor that accumulates the voltage, and the negative (-) diode group connected in parallel to the negative capacitor are connected to the secondary side of the transformer. It may include.

At this time, the (+) side diode group is two diodes connected in series, and the first one of the back pressure stages connected in series to the secondary side of the transformer can withstand the damage of the component due to inrush current during initial charging. It may be configured to include at least two (+) side diode groups connected in parallel to the (+) side capacitor.

In addition, the (-) side diode group is two diodes connected in series, and the first one of the back pressure stages connected in series with the secondary side of the transformer can withstand the damage of the component due to inrush current during initial charging. It may be configured to include at least two (-) side diode groups connected in parallel to the (-) side capacitor.

In this case, the contacts between the two diodes in the (+) side diode group of each back pressure stage and the contacts between the two diodes in the (−) side diode group may be connected to each other.

According to this configuration, the principle of accumulating voltage in each capacitor is the same as described in the (+) side rectifier described above, and thus will be omitted below.

As described above, the present invention constitutes a boost rectification unit in a power supply device for the X-ray generator using a full-wave rectification method or an onion rectification method so as to obtain the same effect as doubling the switching frequency. By differently configuring the capacitance of each capacitor, the tube voltage ripple in the X-ray tube can be reduced, and a good X-ray waveform can be obtained.

In addition, the present invention constitutes a step-up rectifier in the power supply device for the x-ray generator using a full-wave rectification method or onion rectification method to achieve the same effect as to increase the switching frequency twice, for each back pressure stage in the boost rectification unit By configuring the capacitors differently, the reliability of the product can be improved.

According to the present invention, the boost rectifying unit of the power supply device for the x-ray generator may be modified and applied in various forms within the scope of the technical idea of the present invention, and the present invention is not limited to the above embodiment. In addition, the embodiments and drawings are merely for the purpose of describing the contents of the invention in detail, not intended to limit the scope of the technical idea of the invention, the present invention described above is common knowledge in the technical field to which the present invention belongs As those skilled in the art can have various substitutions, modifications, and changes without departing from the technical spirit of the present invention, it is not limited to the above embodiments and the accompanying drawings, of course, and not only the claims to be described below but also claims Judgment should be made including scope and equivalence.

1 is an exemplary view for explaining the principle of obtaining a high voltage of the power supply according to the prior art,

2 is an exemplary view showing a configuration of a power supply device of an x-ray generator according to an embodiment of the present invention,

3 is an exemplary view showing a detailed configuration of the boost rectifying unit 215 shown in FIG.

<Description of Symbols for Main Parts of Drawings>

201: AC power supply

202: charger

203: PCM board

204: lithium polymer battery

205: power control unit

206: sequence control unit

207: PWM IC for tube voltage control

208: PWM IC for tube current control

209, 210: switching element for tube voltage control

211 and 212: switching elements for tube current control

213: Transformer for controlling the tube voltage

214: Filament Control Transformer

215: step-up rectifier

216: x-ray tube

217: tube voltage detector

218: tube current detector

Claims (10)

N back-pressure stages are connected in series to the secondary side of the transformer for controlling the tube voltage, and the voltage induced on the secondary side of the transformer is boosted to N times the high voltage to provide to the (+) terminal of the X-ray tube. ) Rectifier; And N back pressure stages are connected to the secondary side of the transformer in series, and the (-) side rectifying unit boosts the voltage induced on the secondary side of the transformer to N times the high voltage and provides it to the (-) side terminal of the X-ray tube. Step-up rectifier of the power supply for the x-ray generator comprising a. According to claim 1, N back pressure stages of the (+) side rectifying portion, A positive capacitor accumulating the voltage when a negative AC pulse voltage is applied to the secondary side of the transformer; (+) Diode group connected in parallel to the (+) capacitor; A negative capacitor accumulating the voltage when a positive AC pulse voltage is applied; And Step-up rectifier of the power supply for the x-ray generator including a (-) side diode group connected in parallel to the (-) side capacitor on the secondary side of the transformer. The method of claim 2, The (+) side diode group, Step-up rectifier of the power supply for the x-ray generator, characterized in that the two diodes connected in series. The method of claim 2, The first back pressure stage of the back voltage stage connected in series with the secondary side of the transformer includes at least two (+) side diode group connected in parallel to the (+) side capacitor of the power supply for the x-ray generator Boost rectifier. The method of claim 2, The (-) side diode group, Step-up rectifier of the power supply for the x-ray generator, characterized in that the two diodes connected in series. The method of claim 2, The first back voltage stage among the back voltage stages connected in series to the secondary side of the transformer includes at least two (-) side diode group connected in parallel to the (-) side capacitor of the power supply for the x-ray generator Boost rectifier. The method according to claim 1 or 2, N back pressure stages of the (+) side rectifying portion, (7-N) positive capacitors connected in parallel with different capacitor capacities; And (7-N) (-) side capacitors connected in parallel, respectively. The method according to claim 1 or 2, N back pressure stages of the (-) side rectifying portion, (7-N) positive capacitors connected in parallel with different capacitor capacities; And (7-N) (-) side capacitors connected in parallel, respectively. According to claim 1, N back pressure stages of the (-) side rectifying portion, A positive capacitor accumulating the voltage when a negative AC pulse voltage is applied to the secondary side of the transformer; (+) Diode group connected in parallel to the (+) capacitor; A negative capacitor accumulating the voltage when a positive AC pulse voltage is applied; And Step-up rectifier of the power supply for the x-ray generator including a (-) side diode group connected in parallel to the (-) side capacitor on the secondary side of the transformer. The method according to claim 2 or 9, When (-) or (+) AC pulse voltage is applied, N times voltage is accumulated in each of the (+) and (-) capacitors of the N-th back pressure stage connected in series with the secondary side of the transformer. Step-up rectifier of the power supply for the x-ray generator.

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