CN215815783U

CN215815783U - Drive circuit of X-ray tube rotary anode

Info

Publication number: CN215815783U
Application number: CN202122326130.2U
Authority: CN
Inventors: 朱海青
Original assignee: Imd China Co ltd
Current assignee: Imd China Co ltd
Priority date: 2021-09-26
Filing date: 2021-09-26
Publication date: 2022-02-11
Anticipated expiration: 2031-09-26

Abstract

The application relates to a drive circuit of a rotary anode of an X-ray tube, which comprises a starting module, a processing module, an output module, a power supply module and a frequency acquisition module; the power supply module is connected with commercial power and used for regulating and rectifying the commercial power so as to provide input alternating current with specified amplitude and supply voltages with different amplitudes; the starting module is used for accessing a starting command sent from the outside to output a starting signal; the frequency acquisition module is used for acquiring the frequency of input alternating current so as to output a frequency sampling signal; the processing module is used for receiving the starting signal to output a triggering signal; the output module is used for outputting driving voltage with adjustable amplitude when receiving the trigger signal so as to supply power to the load; the processing module is further used for calculating the frequency of the input alternating current according to the frequency sampling signal so as to control the output module to continuously output the driving voltage with the expected amplitude. The power supply control method and the power supply control device have the effect of being capable of stably outputting when the frequency of the network power supply changes.

Description

Drive circuit of X-ray tube rotary anode

Technical Field

The present application relates to the field of electronic medical treatment, and more particularly, to a driving circuit for a rotary anode of an X-ray tube.

Background

In general, a high-power X-ray tube adopts a structure of a rotary anode, and driving the anode to rotate requires that a stator winding is arranged outside an anode part, so that an anode target surface reaches a preset rotating speed in a specific time to bear larger power.

In the related art, a driving circuit generally used for driving the rotation of the rotary anode of the X-ray tube is an analog circuit. When the frequency of the grid power supply changes, the adjustment needs to be carried out in a mode of replacing components, so that the driving circuit of the rotating anode of the X-ray tube can stably output.

For the related art, when the network power frequency changes, it is inconvenient to debug the network power frequency again on site.

SUMMERY OF THE UTILITY MODEL

In order to facilitate stable output when the frequency of a network power supply changes, the application provides a driving circuit of a rotating anode of an X-ray tube.

The technical scheme adopted by the drive circuit of the rotary anode of the X-ray tube is as follows:

a drive circuit of a rotary anode of an X-ray tube comprises a starting module, a processing module, an output module, a power supply module and a frequency acquisition module;

the power supply module is connected with commercial power and used for regulating and rectifying the commercial power so as to provide input alternating current with specified amplitude and supply voltages with different amplitudes;

the starting module is connected with the power supply module and used for accessing a starting command sent from the outside to output a starting signal;

the frequency acquisition module is connected with the power supply module and is used for acquiring the voltage of the input alternating current so as to output a frequency sampling signal;

the processing module is respectively connected with the power supply module and the starting module and used for receiving a starting signal so as to output a triggering signal;

the output module is connected with the processing module and is used for outputting driving voltage with adjustable amplitude when receiving the trigger signal so as to supply power to a load;

the processing module is further connected with a frequency acquisition module and used for calculating the frequency of the alternating current according to the frequency sampling signal so as to control the output module to continuously output the driving voltage with the expected amplitude.

By adopting the technical scheme, the frequency acquisition module can sample the input alternating current, so that the time interval between two adjacent acquisition points is just half of the period of the input alternating current. The processing module can calculate the frequency of the input alternating current according to the time interval between every two received frequency sampling signals, so that the amplitude of the driving voltage output by the output module is controlled to be still unchanged when the frequency of the alternating current is changed, and the stable output state is further achieved.

Optionally, the power supply module includes a filtering protection unit, a transformer, a rectification unit and a switching power supply;

the filter protection unit is connected with the mains supply to output the processed mains supply;

the transformer is connected with the filtering protection unit and used for regulating the voltage of the processed commercial power so as to output input alternating current with specified amplitude;

the rectifying unit is connected with the transformer and used for rectifying the alternating current to output a first amplitude power supply voltage;

the switching power supply is connected with the rectifying unit and used for outputting a second amplitude power supply voltage.

By adopting the technical scheme, the filtering protection unit can perform basic processing on the commercial power and has the function of protecting the circuit. The transformer can change the voltage of the commercial power to obtain input alternating current with proper size. The rectifying unit can rectify an input alternating current of a specified amplitude into a direct current of a specified amplitude. Because the voltages used by all parts in the driving circuit are different, the switching power supply is required to change direct current with specified amplitude into direct current with other amplitudes so as to meet the requirement of the whole driving circuit.

Optionally, the frequency acquisition module includes a bidirectional optical coupler and a switching tube;

the bidirectional optical coupler is connected with the transformer, is connected with the input alternating current and is used for acquiring a zero crossing point of the input alternating current so as to output a zero acquisition signal of a low level;

the switching tube is connected with the bidirectional optical coupler and used for converting the low level of the zero point acquisition signal into the high level so as to output a frequency sampling signal.

By adopting the technical scheme, the bidirectional optical coupler can be switched on when the voltage in the input alternating current is in a non-zero state, and switched off when the voltage is in zero, and the zero crossing point of the input alternating current can be conveniently acquired by matching with the switching tube, so that the processing module can calculate the frequency of the input alternating current according to the time interval between adjacent zero crossing points.

Optionally, the output module includes a trigger unit, a voltage regulator and a load motor;

the trigger unit is connected with the processing module and used for receiving the trigger signal so as to output a driving signal;

the voltage regulating device is respectively connected with the filtering protection unit and the trigger unit and is used for accessing the processed commercial power and regulating and outputting driving voltage with adjustable amplitude after receiving the driving signal;

the load motor is connected with the voltage regulating device to work under the driving voltage.

Through adopting above-mentioned technical scheme, though voltage regulator can adjust drive voltage's amplitude, but receive the influence of net power supply frequency change easily, and then cause drive voltage's amplitude to change. When the processing module calculates the frequency of the input alternating current, the voltage regulating device can be controlled according to the frequency so that the driving voltage is maintained at a desired amplitude value to stabilize the output.

Optionally, one stator winding of the load motor is connected in series with the phase shift capacitor, a branch of the stator winding connected in series with the phase shift capacitor is connected in parallel with the other stator winding, and a common end of the two stator windings is connected with the voltage regulating device;

and the common end of the two stator windings is connected with the voltage regulating device through a protection switch.

By adopting the technical scheme, the phase difference of the current passing through the two stator windings is 90 degrees by the phase shift capacitor, so that a rotating magnetic field can be formed when the stator of the load motor is electrified, and the rotor, namely the anode of the X-ray tube, is driven to rotate. The protection switch can be turned off when there is a fault in the circuit to protect the circuit.

Optionally, the system further comprises two detection and comparison modules;

the two detection and comparison modules are respectively used for detecting the current value flowing through the stator winding after the protection switch is controlled to be closed when the processing module receives the starting signal, outputting a fault prompt signal when the current value is not zero, and outputting a normal state signal when the current value is zero;

the processing module is also respectively connected with the two detection and comparison modules, and is used for controlling the protection switch to be switched off when receiving the fault prompt signal and outputting the trigger signal when receiving the normal state signal.

By adopting the technical scheme, the detection and comparison module can detect the current flowing through the two stator windings when the protection switch is closed, and the current circuit state is judged according to the current. When current flows through the stator winding, the voltage regulating device is considered to have a fault, otherwise, the current circuit is considered to be normal, and the driving circuit is protected when used.

Optionally, the two detection and comparison modules are further respectively configured to detect a current value flowing through the stator winding after the trigger unit drives the voltage regulator to be turned on, output an abnormal prompt signal when the current value is lower than a preset value, and output a normal start signal when the current value is not lower than the preset value;

the processing module is also used for controlling the protection switch to be switched off and not outputting the trigger signal any more when receiving the abnormal prompt signal, and controlling the communication interface connected with the processing module to output a starting success signal when receiving the normal starting signal.

By adopting the technical scheme, the detection and comparison module can also monitor the driving circuit after the driving circuit is started so as to ensure that the driving circuit can normally work and timely detect faults in the driving circuit.

Optionally, the detection and comparison module includes a current detection unit, a processing unit and a comparison unit;

the current detection unit is used for detecting the current value flowing through the stator winding and outputting a current detection signal;

the processing unit is connected with the current detection unit and used for converting a current value reflected by the current detection signal into a corresponding voltage and amplifying the voltage so as to output a voltage detection signal;

the comparison unit is connected with the processing unit and used for outputting a fault prompt signal when the processing module receives a starting signal and controlling the voltage reflected by the voltage detection signal to be non-zero after the protection switch is closed, outputting a state normal signal when the voltage reflected by the voltage detection signal is zero, outputting an abnormal prompt signal when the voltage reflected by the voltage detection signal is lower than a preset value after the trigger unit drives the voltage regulating device to be switched on, and outputting a normal starting signal when the voltage reflected by the voltage detection signal is not lower than the preset value.

By adopting the technical scheme, whether the working state of the current drive circuit is abnormal or not can be judged according to the detected current value, so that the operation safety of the drive circuit is improved.

Optionally, the system further comprises an adjusting module, wherein the adjusting module is connected to the processing module and is used for adjusting the starting time and the maintaining voltage.

By adopting the technical scheme, the starting time is the time for reaching the maximum rotating speed, the maintaining voltage is the voltage capable of maintaining the rotation of the load motor, and the starting time and the maintaining voltage can be adjusted according to the frequency calculated by the processing module due to the influence of the starting time and the maintaining voltage when the frequency of the alternating current changes.

Optionally, the processing module is a single chip microcomputer.

By adopting the technical scheme, the single chip microcomputer is high in integration level, small in size, strong in control capability and high in reliability.

In summary, the present application includes at least one of the following beneficial technical effects:

1. by arranging the frequency acquisition module, the processing module can calculate the frequency of the alternating current, so that the processing module can adjust according to the frequency to control the output module to continuously output the driving voltage with the expected amplitude and keep stable output;

2. the working state of the output module can be monitored in real time by arranging the detection comparison module, faults can be found in time, the circuit is protected, and loss is reduced.

Drawings

Fig. 1 is a system schematic diagram of a drive circuit of an X-ray tube rotary anode according to an embodiment of the present application.

Fig. 2 is a schematic circuit diagram of a power module according to an embodiment of the present application.

Fig. 3 is a circuit diagram of a start module according to an embodiment of the present application.

Fig. 4 is a schematic circuit diagram of the single chip microcomputer and the adjusting module according to the embodiment of the present application.

Fig. 5 is a circuit diagram of an output module according to an embodiment of the present application.

Fig. 6 is a schematic circuit diagram of a detection comparison module according to an embodiment of the present application.

Fig. 7 is a schematic circuit diagram of a frequency acquisition module according to an embodiment of the present application.

Description of reference numerals: 1. a power supply module; 11. a filtering protection unit; 12. a transformer; 13. a rectifying unit; 14. a switching power supply; 2. a starting module; 21. a voltage stabilization unit; 22. a high-speed starting unit; 23. a low-speed starting unit; 3. a single chip microcomputer; 4. an output module; 41. a load motor; 42. a trigger unit; 5. a frequency acquisition module; 6. an adjustment module; 61. a voltage regulating unit; 62. a time adjustment unit; 7. a detection comparison module; 71. current detection means, 72, and processing means; 73. a comparison unit; 8. and a communication interface.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below with reference to fig. 1-7 and the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The embodiment of the application discloses drive circuit of X-ray tube rotating anode can control the rotating of the anode target surface of the rotating anode X-ray tube in a short time, and set the starting time of the maximum rotating speed according to the working mode, and control the maintaining voltage needed by keeping the anode rotating.

Referring to fig. 1, the driving circuit of the rotating anode of the X-ray tube includes a power module 1, a starting module 2, a processing module, an output module 4, a frequency acquisition module 5, an adjusting module 6 and a detection comparison module 7, so that the driving circuit of the present application not only can output stably when the frequency of the network power supply changes, but also can protect the driving circuit when the working state of the driving circuit is abnormal.

Referring to fig. 1 and 2, a power module 1 is connected to a 230V commercial power, and is used for regulating and rectifying the commercial power to output an input alternating current with a specified amplitude and supply voltages with different amplitudes. The power module 1 includes a filter protection unit 11, a transformer 12, a rectification unit 13, and a switching power supply 14.

Specifically, the primary side of the transformer 12 is connected to the mains supply, so that the transformer 12 can regulate the mains supply to output the input alternating current with the specified amplitude. The above-mentioned specified amplitude satisfies the amplitude required by the driving circuit, and in this application, the secondary side of the transformer 12 outputs 12V ac power.

The rectifying unit 13 is connected to the secondary side of the transformer 12, and is connected to the input ac power for rectifying the input ac power with the specified amplitude to convert the input ac power with the specified amplitude into a dc power with the specified amplitude, that is, a first amplitude power supply voltage. The rectifying unit 13 may specifically employ a full-wave rectifying circuit.

It will be appreciated that the voltages required by the various parts of the drive circuit will vary and the power supply module 1 will need to provide a variety of supply voltages. Therefore, the switching power supply 14 is connected to the output terminal of the rectifying unit 13 to convert the first amplitude power supply voltage into the second amplitude power supply voltage and output it. In the present application, the first amplitude supply voltage is 12V and the second amplitude supply voltage is 5V.

In consideration of the special situation that the commercial power jumps due to external factors, the filter protection unit 11 includes a voltage dependent resistor connected in parallel to the commercial power to protect the power module 1.

The filter protection unit 11, the transformer 12, the rectification unit 13, and the switching power supply 14 are all commonly used circuits in various power modules 1, and therefore, a description of each part is not repeated here.

Referring to fig. 1 and 3, the starting module 2 is connected to the power module 1, and is configured to access an externally sent starting command to output a starting signal.

It can be understood that, in order to meet the requirements of the application environment of the driving circuit of the present application, the start command can be divided into a high-speed mode and a low-speed mode. It should be noted that two modes can only be enabled at one time. Correspondingly, the starting module 2 comprises a high-speed starting unit 22 and a low-speed starting unit 23.

Since the high-speed starting unit 22 and the low-speed starting unit 23 work in a similar manner, the high-speed starting unit 22 is taken as an example and is briefly described as follows:

the high-speed startup unit 22 includes an optocoupler OP1, and when the optocoupler OP1 receives a startup command of the high-speed mode, the optocoupler OP1 is turned on and outputs a startup signal. Specifically, the input anode and the input cathode of the optocoupler OP1 are respectively connected to a communication interface 8, wherein the input cathode is switched to a low level. When the communication interface 8 receives the start command, the input anode of the optical coupler OP1 is connected to a high level, and at this time, the photodiode of the optical coupler OP1 is turned on to output an optical electrical signal, and the phototransistor of the optical coupler OP1 receives the optical electrical signal to be turned on, that is, the two output ends of the optical coupler OP1 can be turned on, so that the output end of the high-speed start unit 22 outputs a high level signal, that is, outputs a start signal.

Of course, the low-speed starting unit 23 and the high-speed starting unit 22 may share a common branch.

Preferably, the starting module 2 may further include two voltage stabilizing units 21, where the two voltage stabilizing units 21 are respectively connected to the high-speed starting unit 22 and the low-speed starting unit 23, so that the starting signal output by the high-speed starting unit 22 and the starting signal output by the low-speed starting unit 23 can be output after being stabilized.

Referring to fig. 1 and 4, the processing module is respectively connected to the power module 1 and the start module 2, and is configured to receive a start signal to output a trigger signal. In the application, the processing module is preferably a single chip microcomputer 3, and the model number of the single chip microcomputer is PIC24FV16KM 202-I/SO. Specifically, the pin 17 and the pin 18 of the single chip microcomputer 3 are respectively connected to the output ends of the two voltage stabilizing units 21, and are configured to output a trigger signal when receiving a start signal output by the high-speed start unit 22 or a start signal output by the low-speed start unit 23.

Referring to fig. 1 and 5, the output module 4 is respectively connected to the power module 1 and the single chip microcomputer 3, and is configured to output a driving voltage with an adjustable amplitude when receiving a trigger signal, so as to supply power to a load.

The output module 4 includes a voltage regulating device and a load motor 41.

Wherein, the voltage regulating device is preferably a triac Q1 according to application environment. Triac Q1 is more suitable for ac voltage regulation than other voltage regulation devices. In order to reduce the driving power for driving the triac Q1 and the interference generated when the triac Q1 is triggered, the output module 4 further includes a trigger unit 42 for applying a trigger signal of the singlechip 3 to the triac Q1.

Specifically, the trigger unit 42 includes an optically coupled triac driver OPT 1. And the input anode of the optical coupling bidirectional thyristor driver OPT1 is connected with the No. 7 pin of the singlechip 3 and is used for receiving a trigger signal. When the input anode of the optically coupled triac driver OPT1 receives a trigger signal, its two output terminals can be turned on to output a drive signal. Further, the optically coupled triac driver OPT1 is preferably MOC3021, so that the two output terminals of the optically coupled triac driver OPT1 can be turned on or off at any time, thereby facilitating the control of the state of the triac Q1.

The triac Q1 is respectively connected with the output end of the filter protection circuit and the output end of the optical coupling triac driver OPT1, and is used for accessing the commercial power processed by the filter protection circuit and outputting driving voltage with adjustable amplitude after receiving the driving signal.

One stator winding of the load motor 41 is connected in series with the phase shift capacitor and the stator winding is connected in parallel with the other stator winding, and the common end of the two stator windings is connected with a triac Q1 through a protection switch K1, so that the load motor 41 can form a rotating magnetic field when working under a driving voltage.

The protection switch K1 is connected with the No. 10 pin of the singlechip 3 and is used for controlling the conduction state of the load motor 41 and the triac Q1 so as to protect the circuit. Specifically, the protection switch K1 is a solid-state relay.

The driving circuit of the present application will be further described below in conjunction with the process of starting the load motor 41:

first, it should be noted that when the single chip microcomputer 3 receives the start signal, and before the trigger signal is output, the state of the current output module 4 needs to be determined, so as to output the trigger signal after determining that the output module 4 has no fault. Therefore, when the single chip microcomputer 3 receives the starting signal, the single chip microcomputer 3 firstly controls the protection switch K1 to be closed.

Referring to fig. 1 and 6, in particular, the detection and comparison module 7 is used for detecting the value of current flowing through the stator winding, outputting a fault notification signal when the current value is non-zero, and outputting a state normal signal when the current value is zero. Because the number of the stator windings is two, the number of the detection and comparison modules 7 is also two correspondingly.

Taking one of the detection and comparison modules 7 as an example, the following specific description is given:

the detection comparison module 7 comprises a current detection unit 71, a processing unit 72 and a comparison unit 73;

the current detection unit 71 detects a value of a current flowing through one stator winding, and outputs a current detection signal. It is understood that there are many detecting instruments for detecting and outputting the current value, such as a current sensor, a current tester, a current transformer, and the like. But different processing modes are needed when the current value detected by each instrument is processed. Therefore, when any instrument for detecting current is adopted, a corresponding processing mode should be set. In the present application, the current detection unit 71 is preferably a current transformer. The processing unit 72 and the comparing unit 73 are explained below on the basis thereof.

The processing unit 72 is connected to the current detection unit 71, and is configured to convert the current value reflected by the current detection signal into a corresponding voltage and amplify the voltage to output a voltage detection signal. The processing unit 72 includes a sampling resistor and an operational amplifier U2. The sampling resistor is connected in series with the current detection unit 71 to convert a current value reflected by the current detection signal into a corresponding voltage.

The current value measured by the current transformer is smaller because the current value measured by the current transformer depends on the turn ratio of the primary side and the secondary side and is inversely proportional to the turn ratio of the primary side and the secondary side. Accordingly, the voltage obtained by the sampling resistor is also small, and needs to be amplified by the operational amplifier U2.

The non-inverting input terminal of the operational amplifier U2 is connected to the sampling resistor for amplifying the voltage to output a voltage detection signal. The gain factor of the operational amplifier U2 depends on the resistance of the input resistor and the feedback resistor, and the gain factor of the operational amplifier U2 can be adjusted by changing the resistance of the feedback resistor.

The comparing unit 73 is connected to the processing unit 72, and is configured to output a failure indication signal when the voltage reflected by the voltage detection signal is non-zero, and output a state normal signal when the voltage reflected by the voltage detection signal is zero. Specifically, the comparison unit 73 includes a switching tube Q5. The base electrode of the switching tube Q5 is connected with the output end of the operational amplifier U2, when the voltage value reflected by the voltage detection signal is not lower than the preset value, the switching tube Q5 is conducted, and the collector electrode of the switching tube Q5 outputs low level, namely, a fault prompt signal is output. On the contrary, when the voltage value reflected by the voltage detection signal is lower than the preset value, the switching tube Q5 is turned off, and the collector of the switching tube Q5 outputs a high level, that is, outputs a normal state signal.

In other words, when the protection switch K1 is closed and a current is detected to flow through the two stator windings, that is, the current value reflected by the current detection signal is not zero, and similarly, the voltage value reflected by the voltage detection signal is not zero, the fault indication signal output by the switching tube Q5 can indicate that the triac Q1 has failed. If the current value flowing through the two stator windings is detected to be zero, namely the voltage value reflected by the voltage detection signal is also zero, at the moment, the switching tube Q5 is in an off state, and the state normal signal output by the switching tube Q5 can indicate that the triac Q1 does not have a fault currently.

It is worth noting that the processing unit 72 further comprises peripheral circuits of an operational amplifier U2. The preset value can be adjusted by setting the resistance value of the resistor on the peripheral circuit. Wherein, in the present application, the preset value is 0.7V.

Of course, in order to implement the function of the detection and comparison module 7, a current sensor may be used to detect the current flowing through the stator winding, and a comparator may be used to determine the state of the triac Q1. Other embodiments are provided herein and are not intended to be limiting.

The No. 2 pin and the No. 3 pin of the singlechip 3 are respectively connected with the output ends of the switch tube Q5 and the switch tube Q6 and used for receiving fault prompting signals and normal state signals. When the single chip microcomputer 3 receives the fault prompt signal, the single chip microcomputer 3 controls the protection switch K1 to be switched off so as to avoid the damage caused by continuous heating of the stator winding. When the single chip microcomputer 3 receives the state normal signal, the single chip microcomputer 3 outputs a trigger signal, namely, the optical coupling bidirectional controlled silicon driver OPT1 can drive the triac Q1 to be conducted.

Of course, the detection and comparison module 7 can detect not only the operating state of the triac Q1 after the protection switch K1 is closed, but also the stator winding after the triac Q1 is turned on. Specifically, when the voltage reflected by the voltage detection signal is not lower than a preset value, a normal start signal is output, and when the voltage reflected by the voltage detection signal is lower than the preset value, an abnormal prompt signal is output.

In other words, after the triac Q1 is turned on, when the voltage value reflected by the voltage detection signal is higher than the preset value, the switching tube Q5 is turned on, and the collector of the switching tube Q5 outputs a low level, that is, outputs a normal start signal, which indicates that the driving circuit is currently working normally. On the contrary, when the voltage value reflected by the voltage detection signal is lower than the preset value, the switching tube Q5 is in an off state at the moment, and the collector of the switching tube Q5 outputs a high level, that is, outputs an abnormal prompt signal, which indicates that the current flowing through the stator winding is out of the normal range, that is, indicates that a fault exists in the driving circuit.

Correspondingly, the singlechip 3 is also used for receiving an abnormal prompt signal and a normal starting signal. When receiving the abnormal prompt signal, the singlechip 3 controls the protection switch K1 to be switched off, and simultaneously, the trigger signal is not output any more, so that the optical coupling bidirectional triode thyristor driver OPT1 drives the triac Q1 to be switched off. When receiving the normal starting signal, the singlechip 3 controls the communication interface 8 to output a starting success signal.

It can be understood that pin 11 of the single chip microcomputer 3 is connected with a trigger switch K2, and the trigger switch K2 is connected with the communication interface 8. Normally, the trigger switch K2 is in an open state. However, when the single chip microcomputer 3 receives a normal starting signal, the single chip microcomputer 3 controls the trigger switch K2 to be closed, so that the communication interface 8 outputs a starting success signal.

Referring to fig. 1 and 7, it will be appreciated that the mains power frequency may be 50Hz or 60Hz, which may occasionally fluctuate by ± 1Hz when under a determined mains power. This has an effect on the driving voltage output from the triac Q1, causing the driving voltage to change. Specifically, controlling the conduction angle of the triac Q1 can control the magnitude of the drive voltage. When the frequency of the grid power supply changes, the period of the grid power supply also changes correspondingly, and then the driving voltage corresponding to the same conduction angle changes. Therefore, it is necessary to detect the frequency to adjust the stable output driving voltage according to the current frequency.

The frequency acquisition module 5 is connected with the power supply module 1 and used for acquiring the frequency of the input alternating current so as to output a frequency sampling signal. The frequency acquisition module 5 includes a bidirectional optical coupler OPT2 and a switching tube Q3.

The bidirectional optical coupler OPT2 is connected to the secondary side of the transformer 12, and is connected to the input alternating current for acquiring the zero crossing point of the input alternating current to output a zero point acquisition signal of low level. The two input terminals of the bidirectional photo-coupler OPT2 can be turned on when the voltage is not zero, so that the two output terminals of the bidirectional photo-coupler OPT2 output high level signals. On the contrary, when the voltages connected to the two input ends of the bidirectional optical coupler OPT2 are zero, the two output ends of the bidirectional optical coupler OPT2 output low levels, that is, output zero-point acquisition signals. Since it is most convenient to calculate the frequency from the time interval between zeros in a sine wave, a bidirectional optical coupler OPT2 is employed to acquire the zero crossings.

The base electrode of the switching tube Q3 is connected to the anode output end of the bidirectional optical coupler OPT2, when the base electrode of the switching tube Q3 receives the zero-point acquisition signal, that is, the base electrode of the switching tube Q3 is at a low level, the switching tube Q3 is turned off, and the collector electrode of the switching tube Q3 outputs a high-level signal, that is, a frequency sampling signal. On the contrary, when the base of the switching tube Q3 is at a high level, the switching tube Q3 is turned on, and the collector of the switching tube Q3 outputs a low level signal, i.e., does not output a frequency sampling signal. The NPN type switching transistor Q3 is used in this application. Of course, the switching tube Q3 may also be a PNP type, and only needs to be adaptively adjusted according to requirements.

And a No. 16 pin of the singlechip 3 is connected with a collector of a switching tube Q3 and used for receiving frequency sampling signals, calculating the current frequency of the grid power supply according to the time interval of two adjacent frequency sampling signals, further calculating the conduction angle of the triac Q1, and outputting a trigger signal according to the maintaining voltage and the starting time so that the triac Q1 adjusts the driving voltage to an expected amplitude value.

Referring to fig. 1 and 4, it is worth explaining that the adjusting module 6 is used for presetting the starting time and the maintaining voltage. The adjusting module 6 includes a voltage adjusting unit 61 and a time adjusting unit 62. Specifically, the voltage adjusting unit 61 and the time adjusting unit 62 both adjust the sustain voltage and the start-up time by adjusting the voltage division of the resistor of the potentiometer. The adjustment of the voltage applied to the single chip 3 by voltage division is a conventional means in the art, and therefore, will not be described in detail here.

Pin 14 and pin 15 of the single chip microcomputer 3 are respectively connected with the voltage adjusting unit 61 and the time adjusting unit 62. When the single chip microcomputer 3 receives the frequency sampling signal and calculates the frequency, the current voltage values of the voltage adjusting unit 61 and the time adjusting unit 62 are read, and then the trigger signal output by the single chip microcomputer 3 is adjusted to adjust the starting time and the maintaining voltage.

The implementation principle of the drive circuit of the rotary anode of the X-ray tube in the embodiment of the application is as follows: when the driving circuit receives a starting command, the detection and comparison module 7 can detect the current flowing through the two stator windings in the starting process of the driving circuit so as to monitor the state of the driving circuit in the starting process in real time, find abnormality in time and avoid the damage of the driving circuit. Meanwhile, the frequency acquisition module 5 can acquire the frequency of the grid power supply, so that when the frequency of the grid power supply fluctuates, the single chip microcomputer 3 can adjust the conduction angle of the triac Q1 according to the frequency, and the output module 4 can stably output the driving voltage with the expected amplitude.

The foregoing is a preferred embodiment of the present application and is not intended to limit the scope of the application in any way, and any features disclosed in this specification (including the abstract and drawings) may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

Claims

1. A drive circuit for a rotary anode of an X-ray tube, characterized by: the device comprises a starting module (2), a processing module, an output module (4), a power supply module (1) and a frequency acquisition module (5);

the power supply module (1) is connected with a mains supply and is used for regulating and rectifying the mains supply to provide input alternating current with specified amplitude and supply voltages with different amplitudes;

the starting module (2) is connected with the power supply module (1) and is used for accessing a starting command sent from the outside to output a starting signal;

the frequency acquisition module (5) is connected with the power supply module (1) and is used for acquiring the voltage of the input alternating current so as to output a frequency sampling signal;

the processing module is respectively connected with the power module (1) and the starting module (2) and is used for receiving a starting signal so as to output a triggering signal;

the output module (4) is connected with the processing module and is used for outputting driving voltage with adjustable amplitude when receiving the trigger signal so as to supply power to a load;

the processing module is also connected with a frequency acquisition module (5) and used for calculating the frequency of the alternating current according to the frequency sampling signal so as to control the output module (4) to continuously output the driving voltage with the expected amplitude.

2. The drive circuit for an X-ray tube rotary anode of claim 1, wherein: the power supply module (1) comprises a filtering protection unit (11), a transformer (12), a rectifying unit (13) and a switching power supply (14);

the filtering protection unit (11) is connected with the mains supply to output the processed mains supply;

the transformer (12) is connected with the filtering protection unit (11) and is used for regulating the voltage of the processed commercial power so as to output input alternating current with a specified amplitude;

the rectifying unit (13) is connected with the transformer (12) and is used for rectifying the alternating current to output a first amplitude power supply voltage;

the switching power supply (14) is connected with the rectifying unit (13) and used for outputting a second amplitude power supply voltage.

3. The drive circuit for an X-ray tube rotary anode of claim 2, wherein: the frequency acquisition module (5) comprises a bidirectional optical coupler and a switching tube;

the bidirectional optical coupler is connected with the transformer (12), is connected with the input alternating current and is used for acquiring a zero crossing point of the input alternating current so as to output a zero acquisition signal of a low level;

4. The drive circuit for an X-ray tube rotary anode of claim 3, wherein: the output module (4) comprises a trigger unit (42), a voltage regulating device and a load motor (41);

the trigger unit (42) is connected with the processing module and used for receiving the trigger signal to output a driving signal;

the voltage regulating device is respectively connected with the filtering protection unit (11) and the trigger unit (42) and is used for accessing the processed commercial power and regulating and outputting driving voltage with adjustable amplitude after receiving the driving signal;

the load motor (41) is connected with the voltage regulating device to work under the driving voltage.

5. The drive circuit for an X-ray tube rotary anode of claim 4, wherein: one stator winding of the load motor (41) is connected with the phase-shift capacitor in series, a branch of the stator winding connected with the phase-shift capacitor in series is connected with the other stator winding in parallel, and the common end of the two stator windings is connected with the voltage regulating device;

6. The drive circuit for an X-ray tube rotary anode of claim 5, wherein: the device also comprises two detection and comparison modules (7);

the two detection and comparison modules (7) are respectively used for detecting the current value flowing through the stator winding after the protection switch is controlled to be closed when the processing module receives the starting signal, outputting a fault prompt signal when the current value is not zero, and outputting a normal state signal when the current value is zero;

the processing module is also respectively connected with the two detection and comparison modules (7) and is used for controlling the protection switch to be switched off when receiving the fault prompt signal and outputting the trigger signal when receiving the normal state signal.

7. The drive circuit for an X-ray tube rotary anode of claim 6, wherein: the two detection and comparison modules (7) are respectively used for detecting the current value flowing through the stator winding after the trigger unit (42) drives the voltage regulating device to be conducted, outputting an abnormal prompt signal when the current value is lower than a preset value, and outputting a normal starting signal when the current value is not lower than the preset value;

the processing module is also used for controlling the protection switch to be switched off and not outputting the trigger signal any more when receiving the abnormal prompt signal, and controlling a communication interface (8) connected with the processing module to output a starting success signal when receiving the normal starting signal.

8. The drive circuit for an X-ray tube rotary anode of claim 7, wherein: the detection comparison module (7) comprises a current detection unit (71), a processing unit (72) and a comparison unit (73);

the current detection unit (71) is used for detecting the current value flowing through the stator winding and outputting a current detection signal;

the processing unit (72) is connected with the current detection unit (71) and is used for converting a current value reflected by the current detection signal into a corresponding voltage and amplifying the voltage to output a voltage detection signal;

the comparison unit (73) is connected with the processing unit (72) and is used for outputting a fault prompt signal when the processing module receives a starting signal and controlling the voltage reflected by the voltage detection signal after the protection switch is closed to be non-zero, outputting a state normal signal when the voltage reflected by the voltage detection signal is zero, outputting an abnormal prompt signal when the voltage reflected by the voltage detection signal after the voltage regulating device is driven to be conducted by the trigger unit (42) is lower than a preset value, and outputting a normal starting signal when the voltage reflected by the voltage detection signal is not lower than the preset value.

9. The drive circuit for an X-ray tube rotary anode of claim 1, wherein: the device also comprises an adjusting module (6), wherein the adjusting module (6) is connected with the processing module and is used for adjusting the starting time and the maintaining voltage.

10. Drive circuit of an X-ray tube rotary anode according to any of claims 1-9, characterized in that: the processing module is a singlechip (3).