JPS6362079B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention utilizes a Cottcroft-Walton multistage voltage doubler circuit that can obtain any high voltage with a relatively low voltage transformer by combining a capacitor and a diode. This article relates to the high voltage generator for the X-ray tube used.

[Prior art and its problems]

Generally, one or two sets of Kotscroft-Walton multi-stage voltage doubler circuits are installed on the secondary side of the main transformer, and the DC voltage is converted into an AC voltage having an appropriate frequency and amplitude on the primary side of the main transformer. An X-ray apparatus is equipped with a high-frequency inverter to apply the high voltage generated in the voltage doubler circuit to the X-ray tube, and if the peak value of the secondary voltage of the main transformer is E, then
Since a high voltage of NE proportional to the number N of capacitors in the voltage doubler circuit can be obtained, there is an advantage that a high voltage transformer is not required. There is a problem in that it is difficult to regulate and stabilize the emitted X-ray intensity of the ray tube. In other words, the conventional method for stabilizing tube voltage in this type of X-ray equipment is to extract a feedback signal for automatic tube voltage correction directly from the tube voltage applied to the X-ray tube, and use this feedback signal to control the switching regulator. Generally, the inverter's pulse width is controlled through the inverter, and the DC voltage supplied to the inverter is changed to stabilize the tube voltage against load fluctuations such as tube current. Control loops using regulators not only have poor response and take time to boost voltage, but also have the disadvantage that ripple components and steep pulse-like noise that occur in the output cannot be removed from the tube voltage.

As a solution to these drawbacks, JP-A-Sho
Although the stabilization circuit of No. 54-112120 has been proposed,
This stabilization circuit has two feedback control circuits: an inner control loop provided on the output side of the pulse width controller and an outer control loop provided on the tube voltage output side, making the entire circuit complex. However, there is a problem that the ripple component cannot be completely removed.

Furthermore, when attempting to use a commonly used DC stabilized power supply circuit using variable impedance elements in the aforementioned X-ray apparatus, the charging voltage of one capacitor in the voltage doubler circuit is as high as several thousand volts. Moreover, in order to absorb fluctuations in the output voltage of the voltage doubler circuit due to load fluctuations and keep the tube voltage constant, it is necessary to adjust voltage fluctuations of several thousand volts, which is impossible with currently available transistors. Therefore, in order to increase the withstand voltage, it is conceivable to use a plurality of transistors connected in series, but the circuit configuration becomes complicated due to the need to guarantee variations in the characteristics of individual transistors, and this is not practical.

This invention was made in view of the problems of high voltage generators for X-ray equipment that use Kotscroft-Walton's multi-stage voltage doubler circuit as a high voltage source. An object of the present invention is to provide a high voltage generator for an X-ray apparatus, which is configured to be used as an X-ray apparatus and is capable of absorbing fluctuations in the output voltage of a voltage doubler circuit due to load fluctuations and keeping the tube voltage constant. It is.

[Means for solving problems]

In the present invention, as a technical means for achieving the above-mentioned object, a high voltage generator for an X-ray apparatus is configured as follows. That is, the first invention provides a high-voltage system for an X-ray device that generates an X-ray tube voltage by providing a high-frequency inverter on the primary side of a main transformer and a Kotscroft-Walton multi-stage voltage doubler circuit on the secondary side. In the generator, one of the multi-stage voltage doubler circuits
The capacitor charging voltage on the output side of the stage is divided by a capacitor and a resistor, and a linear voltage control element is provided between the positive output end of this voltage dividing circuit and the X-ray tube.
A tube voltage proportional signal proportional to the tube voltage to be applied to the X-ray tube and a tube voltage setting proportional signal from a source of signals proportional to the desired tube voltage to be applied to the X-ray tube.
A tube voltage stabilizing means that compares in a comparison circuit, changes the impedance of the voltage control element according to the differential signal, and controls the tube voltage to a constant value corresponding to the tube voltage setting proportional signal;
A voltage applied to the voltage control element is detected, a low frequency fluctuation component of the voltage doubler circuit included in the detected voltage is separated from a high frequency pulsation component of the voltage doubler circuit caused by the high frequency inverter, and this high frequency pulsation is detected. A second comparison circuit compares the superimposed signal obtained by converting the component into DC and adding it to the low frequency fluctuation component and the reference signal which sets the maximum value of the voltage applied to the voltage control element, and calculates the difference between the two. A signal is input to a voltage control circuit that controls the high frequency inverter, and the input voltage of the voltage doubler circuit is feedback-controlled so that the maximum value of the voltage applied to the voltage control element is kept constant. A half-wave rectification type high voltage generator is constructed by providing feedback control means for absorbing and removing ripple components of the output voltage supplied to the tube.

Further, the high voltage generator according to the second invention is of a full-wave rectification type, and includes a high-frequency inverter on the primary side of the main transformer and a Kotscroft-Walton multistage voltage doubler circuit on the secondary side. In a high voltage generator for an X-ray device that generates an X-ray tube voltage,
One of the multi-stage booster circuits is installed on each pole side of the X-ray tube.
The capacitor charging voltage on the output side of the first stage of the cathode side voltage doubler circuit of the X-ray tube is divided by the capacitor and the resistor, and the capacitor charging voltage on the output side of the first stage of the anode side voltage doubler circuit is divided by the capacitor and the resistor. A linear voltage control element is provided at the positive output terminal of the voltage dividing circuit on the cathode side and the negative output terminal of the voltage dividing circuit on the anode side. comparing an applied tube voltage proportional signal proportional to each tube voltage of and a bipolar tube voltage setting proportional signal from a source of a signal proportional to a desired tube voltage to be applied to the X-ray tube in different comparison circuits; tube voltage stabilizing means for changing the impedance of the voltage control element according to each of the differential signals and controlling the tube voltage to be equal to or less than a certain value corresponding to the tube voltage setting proportional signal; and the cathode side voltage doubler. A voltage applied to a voltage control element provided in a voltage dividing circuit of the circuit is detected, and a low frequency fluctuation component of the cathode side voltage doubler circuit and a high frequency pulsation component of the voltage doubler circuit caused by the high frequency inverter are included in this detected voltage. A superimposed signal obtained by converting the high-frequency pulsating component into a direct current and adding it to the low-frequency fluctuation component, and a reference signal that sets the maximum value of the voltage applied to the voltage control element, are processed by another comparison circuit. By inputting the differential signal into a voltage control circuit that controls the high-frequency inverter and feedback-controlling the input voltage of the cathode side voltage doubler circuit, the maximum value of the voltage applied to the voltage control element is determined. and feedback control means for controlling the voltage to be less than a certain value corresponding to the reference signal and absorbing and removing ripple components of the output voltage supplied to the X-ray tube.

[Effect]

With the above configuration, in both half-wave rectification type and full-wave rectification type, the maximum applied voltage to the voltage control element set by the reference signal corresponds to the tube voltage set on the secondary side of the transformer. It is generated superimposed on the voltage. When low frequency fluctuations and high frequency pulsations occur in the voltage doubler circuit, the voltage applied to the voltage control element fluctuates. After separating the detected applied voltage into a low-frequency fluctuation component and a high-frequency pulsation component, only the high-frequency pulsation component is converted to DC and added again. Voltage control is performed by differential fluctuation between this superimposed signal and the reference signal. The input voltage of the voltage doubler circuit is feedback-controlled via the circuit and the high-frequency inverter, and the maximum value of the voltage applied to the voltage control element is controlled to be below a certain value corresponding to the reference signal. By setting the maximum value of the voltage applied to this voltage control element to be larger than the fluctuation value of the high frequency ripple component, the ripple component of the output voltage supplied to the X-ray tube is absorbed by the voltage applied to the voltage control element. removed.

Further, a tube voltage proportional signal proportional to the tube voltage applied to the X-ray tube and a tube voltage setting proportional signal are compared in the first comparison circuit, and the impedance of the voltage control element is feedback-controlled by the differential signal. By this, the tube voltage is controlled to a constant value corresponding to the tube voltage setting proportional signal.

The high voltage generation circuit of this X-ray device divides the capacitor charging voltage on the output side of the first stage of the multi-stage voltage doubler circuit using a capacitor and a resistor, and connects the positive output end of this voltage divider circuit to the X-ray tube. Since a linear voltage control element is provided in between, only a voltage of about several hundred volts is applied to the linear voltage control element, so a commercially available transistor or the like can be used.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 shows the block configuration of one embodiment of this invention, and 1 is a product AC power supply, for example, 50V at 200V AC.
Generates commercial AC voltage at Hz or 60Hz. This commercial AC voltage is full-wave rectified and smoothed by the rectifier circuit 2 and converted into a DC voltage. The output voltage 3 of the rectifier circuit 2 is input to a voltage control circuit of an opening/closing control type generally called a switching regulator. As is well known, this voltage control circuit is composed of a switching transistor, a pulse generator, a pulse width control section, etc., and the input signal 5 to the pulse width control section is the differential voltage of the comparison amplifier circuit 6. This input signal 5 controls the width of the periodic square wave pulse output from the pulse generator. A reference signal source 7 that outputs a reference signal 8 to the comparison amplifier circuit 6 sets a collector-emitter voltage of a control transistor which is a linear voltage control element 30 to be described later. The input signal 9 of the comparison amplifier circuit 6 that is compared with this reference signal 8 is a feedback voltage signal detected in a system that controls the tube voltage using the output voltage 10 of the voltage control circuit 4, and 10 is feedback-controlled by the reference signal 8 to a constant value.

Reference numeral 11 denotes a high frequency inverter that converts the DC output voltage 10 of the voltage control circuit 4 into AC, and is, for example, a multi-excitation type inverter consisting of two switching transistors that are turned on and off alternately and a high frequency pulse source. The high-voltage transformer 12 has a primary winding that is push-pull driven by a high-frequency inverter 11 and a secondary winding that generates high voltage. The input signal is input into a half-wave rectifier. The output high voltage of the multi-stage voltage doubler circuit 16 is supplied to the X-ray tube 18 via a tube voltage stabilization circuit 19, which is a main part of the present invention and will be explained in detail in FIG. X-ray tube 1
8, a desired tube voltage 21 set by the operator in the tube voltage setting circuit 20 is applied.

The output voltage 22 of the tube voltage stabilizing circuit 19 is a feedback signal proportional to the tube voltage 21, and this output signal has a minimum cutoff frequency of 1 KHz, for example.
The low-pass filter 23 and the highest cut-off frequency are
For example, it is input in parallel to a 7.5KHz high-pass filter 24. 25 is a smoothing circuit that smooths the high-frequency pulsation signal 29 that is the output of the high-pass filter 24 and converts it into a direct current. Voltage 21 fluctuation signal 2
.

In addition, the high voltage transformer 14 and the multistage voltage doubler circuit 1
6, if the high voltage transformer 13 and two sets of multi-stage voltage doubler circuits 17A and 17B are combined, a full-wave rectification type configuration will be obtained. That is, the output 15 on the secondary side of the high voltage transformer 12
A and 15B are multistage voltage doubler circuits 17A and 17, respectively.
B, one multi-stage voltage doubler circuit 17A generates a positive high voltage with respect to ground, and this
The voltage is applied to the anode of the wire tube 18, and the other multi-stage voltage doubler circuit 1
7B generates a negative high voltage and sends it to X-ray tube 1.
8 cathode.

FIG. 2 is a detailed block configuration diagram of the tube voltage stabilizing circuit 19 shown in FIG.
Components that are the same as those in the figures are given the same reference numerals, and their explanations will be omitted. 30 is a linear voltage control element consisting of a transistor installed in the collector, and the base current Ib is controlled by the differential signal of the comparator amplifier 31. This comparison amplifier 31 includes a tube voltage setting circuit 2.
0 and the tube voltage setting proportional signal ei generated at the movable contact 32 and the tube voltage applied to the X-ray tube 18.
Tube voltage proportional signal obtained by dividing Eo with partial pressure low resistors Ra and Rb
Ea is input. When ei=Ea is in equilibrium, tube voltage Eo
is set to Eo=Ra+Rb/Ra·ei. The multi-stage voltage doubler circuit 16 is a 10-stage type, and the capacity is, for example,
21 0.03μF capacitors C and 20 diodes 33 with the same voltage resistance as the capacitors C.
It is composed of. In addition, in the first stage, the capacitor charging voltage is divided by two capacitors C ₁ and C ₂ and resistors R ₁ and R ₂ , and the ratio of the resistance values of resistors R ₁ and R ₂ is 1:8.3. do. In addition, the collector-emitter voltage V _CE of the voltage control element 30 is also divided by two voltage dividing resistors R ₃ and R ₄ , and a detection voltage proportional to the collector-emitter voltage V _CE generated at this voltage dividing point is generated. is input to the aforementioned low-pass filter 23 and high-pass filter 24. The diode 34 is for reducing the voltage burden on the voltage control element, and a resistor connected in parallel with this diode 34
R5 is for protecting the voltage control element 30.

Next, the operation of the above embodiment will be explained. In the Kotscroft-Walton multi-stage voltage doubler circuit 16, when a load current is actually applied, the voltage distribution of each capacitor C is not perfect as shown in the calculation, and the voltage drop ΔV and the high frequency generated by the high frequency inverter 11 are A pulsating voltage δV occurs. That is, it is expressed by the following formula: ΔV=io/f·c(2/3n ³ +nz/2+n/3) (1) δV=io/f·c·n(n+1)/2 (2). In addition, is high frequency inverter 1
1, c is the capacitance of the capacitor C, n is the number of stages in the multistage voltage doubler circuit 11, and io is the tube current of the X-ray tube. In order to maintain the tube voltage Eo at the set value, it is necessary to detect the voltage drop ΔV and the high frequency pulsating voltage δV mentioned above and perform feedback control on each. In this invention, the base current Ib of the voltage control element 30 is Feedback control is performed using a differential signal between the setting proportional signal ei and the tube voltage proportional signal Ea, and the voltage drop ΔV is absorbed. On the other hand, a voltage larger than the high-frequency pulsating voltage δV generated in the range of variation of the tube current io is set as the collector-emitter voltage V _CE of the voltage control element 30 using the reference signal 8, and this collector-emitter voltage V _CE The detection signal of
By controlling the secondary voltage Ei of the high-voltage transformer 12 through the feedback control system 1, the collector-emitter voltage _VCE is controlled to be below the maximum applied voltage set by the reference signal 8, and the high-frequency pulsating voltage δV is absorbed and removed.

Next, a more detailed explanation will be given using specific numerical values with reference to FIGS. 3 and 4. Now, the number of stages in Kotscroft-Walton's multi-stage voltage doubler circuit 16 is 10.
The smoothing capacitor C is 0.03 μF, the operating frequency of the multi-stage voltage doubler 16 is 25 KHz, and the fluctuation of the tube current io is 0 to 0.
3mA, and the set tube voltage Eo is 60KV. In the case of no load, the input voltage Ei to obtain a tube voltage Eo of 60KV is 3000V, and the ripple voltage δV and voltage drop ΔV are zero. Assuming that feedback control of the primary side of the transformer 12 and control of the base current Ib of the voltage control element 30 are not performed,
When 3mA is required as the tube current io, the voltage drop ΔV is 2880V from the above equation (1), and similarly (2)
From the formula, the ripple voltage ΔV is 220V, which appears as output fluctuation.

Therefore, for load fluctuations of 0 to 3 mA, the tube voltage
To keep Eo constant at 60KV, ΔV + δV = 2880
It is necessary to adjust the fluctuation of +220 = 3100V. Assuming that the voltage sharing between the collector and emitter of the voltage control element 30 in a no-load state is 400V, an input voltage Ei of 3020V is supplied so that Ea+E _R =60400V in a no-load state. At this time, voltage dividing resistor R ₁ ,
If the voltages across R ₂ are E _R1 and E _R2 , E _R = E _R2 + E _R2
= 6040V, and from R ₁ :R ₂ = 1:8.3, E _R1 = 6040/9.3 = 649.5≒650V. Therefore, the output voltage at the output terminal 35 of the voltage control element 30 is E _R1
−V _CE = 250V, and the voltage control element 30
400V is absorbed and the tube voltage Eo becomes 60KV.

On the other hand, when the tube current io is 3 mA, from equations (1) and (2), ΔV = 2880V, δV = 220V, and ΔV + δV
= 3100V fluctuation. Here, ΔV+V _CE =
It is necessary to set the input power Ei such that only 2880V + 400V = 3280V is output more than 60KV. Therefore, Ei=60000+3200/20=3164V. When this Ei = 3164V is applied, when io = 0mA, E _R =
E _R1 + E _R2 = 6328V, but the voltage drop ΔV' and ripple voltage δV' of the voltage dividing resistor R ₁ + R ₂ when io = 3 mA are ΔV' = io/f・c・n, δV′=io /f・c
・From the equation of n, ΔV′=40V, δV′=40V. This state is shown in the time chart of E _R and time in FIG. 3A.

Also, when io = 3mA, E _R1 = 6328/9.3 = 680.43≒680V, and the voltage drop ∆V and knotple voltage across the voltage dividing resistor _R1 are ∆V = 40/9.3≒4.3V, δV = 40/ 9.3≒4.3V. This state is shown in the time chart of the voltage E _R1 across the voltage dividing resistor R ₁ in FIG. 3C.

Also, if Ei = 3164V is applied as described above, E _9L = 3164×20−3164×2−(ΔV−ΔV′)−
(δV−δV′)=31640×20−3164×2−(2880−40)
−(220−40)=53932V. However, E _9L is the lowest voltage of the nine stages between the points 37 and 38 of the voltage doubler circuit 16. This state is expressed as points 37 and 38 in Figure 3B.
The time chart shows the nine stages of voltage E ₉ between .

Furthermore, when applying Ei=3164V,
When io=0mA, E _R2 =3164×2×8・3/9.3=5647.6≒5648V. Also, ΔE _R2 = ΔV′×8.3/9.3=35.7≒36V, and δE _R2 = δV′×8.3/9.3=35.7≒36V. However, ΔE _R2 and ΔE _R2 are the voltage drop and ripple voltage of the voltage dividing resistor R ₂ . This state is expressed by the voltage dividing resistor shown in Figure 3D.
The voltage across _R2 is shown in the time chart of E _R2 .

When io = 3mA, the voltage between points 39 and 38 is
As is clear from Figure 3 A and B, E _9P + E _RP =
54112 + 6288 = 60400V E _9L + E _RL = 53932 + 6248 = 60180V. Therefore, (E _9P + E _RP ) - (E _9L + E _RL ) = 220V. Therefore, the voltage that the voltage control element 30 needs to absorb at the bottom of the ripple is E _9P +E _RP −60000=
It becomes 400V.

Also, when io = 3 mA, the total ripple voltage δV generated between points 39 and 38 is calculated from equation (2) as δV =
3000/25000×0.03× ^10-6 ×10×(10-1)/2=220V
Therefore, this voltage δV = 220V is (E _9P + E _RP ) - (E _9L +
E _RL ) = 60400 - 60180 = 220V, which is the maximum difference in voltage that the voltage control element 30 absorbs in order to stabilize the tube voltage Eo at 60KV.

This means that by controlling the collector-emitter voltage V _CE of the voltage control element 30, which changes with pulsation, to 400 V or less, the ripple voltage δV is absorbed by the collector-emitter voltage V _CE , and the tube voltage This shows that it does not appear in Eo.

Figure 4 shows a time chart when the tube voltage Eo is set to 40KV and io = 0 to 3mA, and A, B, C, and D in the same figure are A, B, and C in Figure 3. ,D.

Fig. 5 shows a full-wave rectification system with two sets of multi-stage voltage doubler circuits 15A and 15B, and in the figure, the same parts as in Figs. The explanation will be omitted. The voltage control elements 30 and 41 are of the same standard, and the other voltage control element 41 is installed between the negative electrode 42 of the voltage doubler circuit 17A and the ground 43 as a collector grounding element, and the tube voltage from the contact linked to the tube voltage setting circuit is controlled. The impedance of the voltage control element 41 is controlled by a comparator amplifier 44 which receives the setting proportional signal and the tube voltage proportional signal from the voltage dividing resistor Ra. However, the collector-emitter voltage of this voltage control element 41 is not detected.
This device has a voltage doubler circuit 1 by a voltage control element 30.
The effect of stabilizing the high voltage in the negative half cycle of 7B is the same as in the case of FIG. 2, and the voltage control element 41
The stabilizing circuit mainly controls the high voltage of the positive half cycle of the voltage doubler circuit 17A in a similar manner.

〔Effect of the invention〕

This invention is constructed and operates as described above,
According to the high voltage generator of the X-ray apparatus of this invention,
In both half-wave rectification type and full-wave rectification type, a voltage larger than the ripple voltage generated in the range of tube current fluctuation is applied in the no-load state, and the voltage between the collector and emitter of the voltage control element is adjusted. In addition to absorbing and removing ripple voltage through feedback control to keep it below the maximum value,
The impedance of the voltage control element is feedback-controlled using a differential signal between the tube voltage proportional signal and the tube voltage setting proportional signal to maintain the tube voltage constant, completely eliminating the effects of voltage drop and high frequency ripple components. can do. Moreover, since the capacitor charging voltage in the first stage of the voltage doubler circuit is divided between the capacitor and the resistor and applied to the voltage control element, a commercially available transistor can be used as the voltage control element, and it is generally Since transistors have frequency characteristics of several MHz or more, they also have excellent responsiveness.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a high voltage generator for an X-ray apparatus according to an embodiment of the present invention, Fig. 2 is a more detailed block diagram thereof, and Figs. 3 and 4 each show a tube voltage of 60KV. FIG. 2 is a timing chart when the voltage is set to 40 KV, and FIG. 5 is a block diagram of another embodiment of the present invention. 6... Second comparison circuit, 7... Reference signal source, 11...
High frequency inverter, 12, 13... transformer, 16,
17A, 17B...Multi-stage pressure booster circuit, 18...X-ray tube,
19...Tube voltage stabilization circuit, 30, 41...Voltage control element, _C1 , _C2 ...Voltage dividing capacitor, _R1 , _R2 ...Voltage dividing resistor.

Claims (1)

[Claims] 1. A high frequency inverter on the primary side of the main transformer, 2.
In a high voltage generator of an X-ray apparatus that is equipped with a Kotscroft-Walton multi-stage voltage doubler circuit on the next side and generates an X-ray tube voltage, the capacitor charging voltage on the output side of the first stage of the multi-stage voltage doubler circuit is connected to the capacitor. and a resistor, a linear voltage control element is provided between the positive output end of this voltage dividing circuit and the X-ray tube, and a tube voltage proportional signal proportional to the tube voltage applied to the X-ray tube; A tube voltage setting proportional signal from a signal source proportional to a desired tube voltage to be applied to the X-ray tube is compared in a first comparator circuit, and the impedance of the voltage control element is determined by the differential signal. a tube voltage stabilizing means for controlling the tube voltage to be equal to or less than a certain value corresponding to the tube voltage setting proportional signal; The low frequency fluctuation component of the voltage doubler circuit and the high frequency pulsation component of the voltage doubler circuit caused by the high frequency inverter are separated, and the high frequency pulsation component is converted into DC and added to the low frequency fluctuation component, resulting in a superimposed signal, and the voltage control A second comparator circuit compares the reference signal that sets the maximum value of the voltage applied to the element, and inputs the differential signal to the voltage control circuit that controls the high frequency inverter to control the voltage doubler circuit. feedback control means for controlling the maximum value of the voltage applied to the voltage control element to be constant by feedback-controlling the input voltage of the X-ray tube, and absorbing and removing ripple components of the output voltage supplied to the X-ray tube. A high voltage generator for an X-ray apparatus, characterized in that: 2 A high frequency inverter is installed on the primary side of the main transformer, 2
In a high voltage generator for an X-ray apparatus that is equipped with a Kotscroft-Walton multi-stage voltage doubler circuit on the next side to generate an X-ray tube voltage, one set of the multi-stage voltage doubler circuits is provided on each pole side of the X-ray tube. , the capacitor charging voltage on the output side of the first stage of the cathode side voltage doubler circuit of the X-ray tube is divided by a capacitor and a resistor, and the capacitor charging voltage on the output side of the first stage of the anode side voltage doubler circuit is divided by the capacitor. A linear voltage control element is provided at the positive output terminal of the voltage dividing circuit on the cathode side and a negative output terminal of the voltage dividing circuit on the anode side, respectively. The applied tube voltage proportional signal proportional to the voltage and the bipolar tube voltage setting proportional signal from the source of the signal proportional to the desired tube voltage to be applied to the X-ray tube are compared in different comparison circuits, and each difference is calculated. tube voltage stabilizing means that changes the impedance of the voltage control element according to a dynamic signal and controls the tube voltage to a constant value corresponding to the tube voltage setting proportional signal;
A voltage applied to a voltage control element provided in a voltage dividing circuit of the cathode side voltage doubler circuit is detected, and a low frequency fluctuation component of the cathode side voltage doubler circuit included in this detected voltage and the voltage doubler by the high frequency inverter are detected. A superimposed signal obtained by separating the high frequency pulsating component of the circuit, converting the high frequency pulsating component into DC and adding it to the low frequency fluctuation component, and a reference signal that sets the maximum value of the voltage applied to the voltage control element, The differential signal is input to a voltage control circuit that controls the high-frequency inverter, and the input voltage of the cathode side voltage doubler circuit is feedback-controlled, thereby controlling the voltage to the voltage control element. The X-ray device is characterized in that it is provided with feedback control means for controlling the maximum value of the applied voltage to be equal to or less than a certain value corresponding to the reference signal and for absorbing and removing ripple components of the output voltage supplied to the X-ray tube. Equipment high voltage generator.