CN108834294A - A kind of heater current closed loop sample circuit and X-ray high-frequency and high-voltage generator - Google Patents
A kind of heater current closed loop sample circuit and X-ray high-frequency and high-voltage generator Download PDFInfo
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- CN108834294A CN108834294A CN201810942259.6A CN201810942259A CN108834294A CN 108834294 A CN108834294 A CN 108834294A CN 201810942259 A CN201810942259 A CN 201810942259A CN 108834294 A CN108834294 A CN 108834294A
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05G—X-RAY TECHNIQUE
- H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
- H05G1/08—Electrical details
- H05G1/26—Measuring, controlling or protecting
- H05G1/30—Controlling
- H05G1/34—Anode current, heater current or heater voltage of X-ray tube
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Abstract
The invention discloses a kind of heater current closed loop sample circuit and X-ray high-frequency and high-voltage generators, the heater current closed loop sample circuit is arranged between load circuit and heater current closed loop circuit, including the current detection circuit being successively electrically connected, input filter circuit, RMS-DC converter circuit and voltage follow output circuit, the heater current closed loop sample circuit is for sampling the ac current signal for flowing through the load circuit, and the ac current signal is converted into setting power DC voltage signal and is exported again to the closed loop feedback control of the heater current closed loop circuit to complete heater current.The present invention improves the sampling precision to exchange heater current by setting heater current closed loop sample circuit, improves closed loop gain control precision, tube current precision and imaging definition indirectly.
Description
Technical field
The present invention relates to power technique fields, high more particularly to a kind of heater current closed loop sample circuit and X-ray
Frequency high pressure generator.
Background technique
In medical imaging equipment digital imaging technology, strong electrical field is needed to excite electron cloud, X-ray is generated, wherein high
Electric field needed for frequency high pressure generator is used to X-ray tube.
In the prior art, high-frequency and high-voltage generator is in the case where same tube voltage, to filament heating for a period of time after,
There is different tube currents in the heater current of same bulb.Therefore the low stability of current precision of X-ray tube is poor in the prior art.
It is tens of thousands of to ten tens of thousands of that the major function of high-frequency and high-voltage generator, which is the AC conversion of the 380V of power frequency input,
The high voltage direct current of volt, in order to reduce the volume of generator, we generally will carry out again high frequency after the AC rectification of 380V
Inversion, the alternating-current pulse after inversion are finally output to load by high-tension cable by generator boosting, rectification.Here negative
Load is exactly that the tube filament after heating has many electronics and flow through inside filament, work as lamp as soon as heating to filament electric current
When silk is in a strong electrical field, movement under the action of strong electrical field of the electrons of filament surface forms tube current, according to China
People's republic's standard GB/T 9706.3 requires medical high-frequency and high-voltage generator tube current error precision range ± 20%
Within.
In existing gain control improves, in order to control the precision of tube current, double circle structure is generally used, that is, take
Heater current inner loop control and tube current outer loop control.
It when wherein, for heater current inner loop control, needs to acquire filament current value, according to collected value VoutWith it is pre-
The setting a reference value V that first many experiments obtainrefCompare, the difference compared is input to control core by subsequent error amplifier
Piece carries out closed loop adjusting, and traditional sample circuit generallys use current transformer and is connected on the circuit of driving filament supply, mutually
Electric current is converted to voltage signal by the resistance of sensor pair side parallel connection, and voltage signal is rectified into V through full-bridge bridge rectifier againout
After be sent to conditioning circuit, since each rectifying path of full-bridge bridge rectifier has two groups of diodes, use general-purpose diode one
A diode tube pressuring drop 0.7V or so, using Schottky diode tube voltage drop 0.3V or so, voltage that when small current samples
For value in 2V or so, sampled voltage subtracts 2 diode tube pressuring drops again, and when tube voltage drop minimum is 0.6V, in 2V sampled voltage, just
Only 1.4V is sent to rear class conditioning circuit, caused by error have reached 30%, very not to subsequent filament closed loop conditioning circuit
Benefit.
Therefore, the sampling technique of existing heater current closed-loop control needs to improve.
Summary of the invention
For the present invention for the technical problem present on, it is higher to provide a kind of sampling precision, improves closed-loop control precision, pipe
The heater current closed loop sample circuit and X-ray high-frequency and high-voltage generator of current precision and imaging definition.
In a first aspect, the technical solution that embodiment of the present invention provides is：A kind of heater current closed loop sample circuit is provided,
It is arranged between load circuit and heater current closed loop circuit, including current detection circuit, the input filter being successively electrically connected
Circuit, RMS-DC converter circuit and voltage follow output circuit,
The current detection circuit is for sampling the ac current signal for flowing through the load circuit and by the ac current signal
It is converted into ac voltage signal；
The input filter circuit is for being filtered and inputting to the ac voltage signal that the current detection circuit samples
To the RMS-DC converter circuit；
The RMS-DC converter circuit for the ac voltage signal of input to be converted into d. c. voltage signal, and passes through
It is exported after filtering；
The voltage follow output circuit is exported again after being used to carry out the d. c. voltage signal power amplification to filament electricity
Closed loop circuit is flowed to complete the closed loop feedback control of heater current.
Preferably, the load circuit be high-frequency and high-voltage generator load, including X-ray bulb and with the X-ray ball
The storage capacitor of pipe concatenation.
Preferably, which includes current transformer and sample resistance, the current transformer primary side and the X
Ray tube connection, secondary side is connected the sample resistance.
Wherein, which includes resistance capacitance filter circuit and integral filter circuit.
Further, which includes the 4th resistance and the 5th electricity for filtering out HF noise signal
Hold, the 4th resistance connect with the sample resistance one end, the other end the first chip of input, the 4th resistance and first chip it
Between connect the 5th capacitor, the 5th capacity earth；The integral filter circuit include the 5th resistance and the 6th capacitor and this
The inside amplifier unit of one chip, the 5th resistance connect the input terminal of the 4th resistance and first chip, the 5th resistance
It connects the 6th capacitor, the output end of the 6th capacitor connects the inside amplifier unit.
Preferably, the RMS-DC converter circuit include power supply, the voltage conversion circuit that is set in first chip
And decoupling capacitor group.
Wherein, which includes the second capacitor, third capacitor and the 4th capacitor, which includes first
Power end and second source end, second capacitor are the filter capacitor of the voltage conversion circuit direct current output of first chip；
The third capacitor is the decoupling capacitor of first power end；4th capacitor is the decoupling capacitor at the second source end；This first
The enable end of chip connects current-limiting resistance.
The voltage follow output circuit connects the DC output end of voltage conversion circuit in first chip.
When it is implemented, the voltage follow output circuit includes the second chip, first capacitor and first resistor, this second
The non-inverting input terminal of chip connects the DC output end of voltage conversion circuit in first chip, the output string of second chip
It is coupled to one end of the second current-limiting resistance, which connects the heater current closed loop circuit；Second chip
The first offset side ground connection, the second offset side of second chip concatenates the first capacitor, the output end feedback of second chip
To the inverting input terminal of second chip.
Second aspect, the technical solution that embodiment of the present invention provides are：A kind of X-ray high-frequency and high-voltage generator is provided,
Including central control unit and connect the rectification unit of the central control unit, high-frequency inversion unit and heater current closed loop electricity
Road, the output of the high-frequency inversion unit are connected to the load circuit, further include heater current closed loop sample circuit above-mentioned, the lamp
Silk current closed-loop sample circuit converts the ac current signal for sampling the ac current signal for flowing through the load circuit
It is exported again at setting power DC voltage signal to the closed loop feedback control of the heater current closed loop circuit to complete heater current.
The beneficial effect of embodiment of the present invention is：The heater current closed loop sample circuit and X-ray of the present embodiment are high
The AC signal of different frequency is directly changed into the sample circuit of direct current virtual value by being arranged, solved by frequency high pressure generator
Bridge rectifier bring diode tube pressuring drop in traditional sampling circuit, and sampling is easily caused under low voltage condition
The larger problem of error substantially increases the sampling precision of heater current, while the sampling raising pair of High-accuracy direct current virtual value
The precision of subsequent closed loop gain control guarantees the clarity of patient's film making image to improve the precision of tube current.And this
The heater current closed loop sample circuit accuracy of invention is high, circuit structure is simple.
Detailed description of the invention
Fig. 1 is the circuit module figure of heater current closed loop sample circuit of the present invention；
Fig. 2 is the circuit structure diagram of the heater current closed loop sample circuit of the embodiment of the present invention；And
Fig. 3 is the circuit module figure of the X-ray high-frequency and high-voltage generator of the embodiment of the present invention.
Specific embodiment
Understand in order to make the object, technical scheme and advantages of the embodiment of the invention clearer, with reference to the accompanying drawing to this hair
Bright embodiment is described in further detail.Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but simultaneously
It is not as a limitation of the invention.
Fig. 1 is please referred to, in order to improve heater current closed loop gain, to improve x-ray imaging clarity, the present invention relates to adopt
The higher heater current closed loop sample circuit of sample precision and the X-ray high-frequency and high-voltage for using the heater current closed loop sample circuit
Generator.
The heater current closed loop sample circuit includes current detection circuit 2, input filter circuit 3, RMS-DC converter circuit 4
And voltage follow output circuit 5.
The output of the X-ray high-frequency and high-voltage generator is connected to load circuit 1.
Please also refer to Fig. 2, in the present embodiment, which is applied in medical X ray machine.This is negative
Carry the conventional load circuit that circuit 1 is X-ray production apparatus, including bulb Q11 and storage capacitor C17.There is filament inside bulb Q11.
In order to couple the driving signal for flowing through filament, the current detection circuit 2 by current transformer, such as the first mutual inductor CT21 with
The driving signal coupling of the filament of bulb Q11 is connected.
The storage capacitor of the load circuit 1, that is, the 7th capacitor C17 are connected in parallel on the both ends bulb Q11, receive external height
Energy storage filters after piezoelectricity energy, after external high-frequency and high-voltage generator energy is sent, in bulb Q11 both ends generation+KV and-KV
High pressure, the electronics for flowing through heater current moves under strong electric field, generates tube current.Tube current is according to national standard GB's 9706.3
It is required that error range control is within ± 20%.
The current detection circuit 2, by current transformer, such as the first mutual inductor CT21 and sampling resistor, such as third
Resistance R23 composition, for sampling heater current according to a certain percentage, sample rate current flows through sampling resistor, and current signal is become
Change voltage signal into, voltage signal is output to the input filter circuit 3 on the first chip U1 again.
In the present embodiment, first chip U1 can use high-precision RMS-DC converter chip, for example, by using chip
AD637, thus the virtual value for the complicated wave form that high precision computation is sampled from the heater current.
The input filter circuit 3, for receive current detection circuit 2 sampling ac voltage signal, carry out RC filtering with
And after First-order Integral filtering, it is output to the input terminal of the first chip U1.
The RMS-DC converter circuit 4, the AC signal of the different frequency for that will input, by internal absolute value circuit,
Such as active rectifier, it is converted into direct current virtual value, is output to the voltage follow output circuit 5.
The voltage follow output circuit 5, the direct current signal for exporting RMS-DC converter circuit 4 carry out power amplification,
Anti-interference ability is improved, then is output to the heater current closed loop circuit 6.The heater current closed loop circuit 6 is external connection circuit.
This will exchange heater current and be converted into the heater current closed loop sample circuit of direct current virtual value and correspond to X-ray height
The working principle of frequency high pressure generator is：
After bulb Q11 filament in load circuit 1 flows through electric current, the mutual inductor with current detection circuit 2, such as first mutually
Sensor CT21 series connection, mutual inductor collect heater current, flow through sampling resistor, such as 3rd resistor with certain proportion output electric current
R23.Current signal at sampling resistor both ends is converted into voltage signal, and sampling resistor is connected with input filter circuit 3, voltage
Signal is input to direct current virtual value after the resistance capacitance filter circuit of input filter circuit 3 and First-order Integral network filtering
The first chip U1 in conversion chip, such as the present embodiment, by direct current RMS-DC converter chip interior absolute value circuit, such as
Active rectifier after ac voltage signal is converted into DC voltage, is output to rear class voltage follow output circuit 5, then export
To external filament current closed-loop circuit 6.
The heater current closed loop sample circuit and X-ray high-frequency and high-voltage generator of the present embodiment pass through setting sampling electricity
The AC signal of different frequency is directly changed into direct current virtual value by road, improves the sampling precision of heater current, while high-precision
The sampling of degree direct current virtual value improves the precision controlled subsequent closed loop gain, to improve the precision of tube current, guarantees disease
The clarity of people's film making image.
Embodiment 1
As shown in figure 3, the present embodiment introduces X-ray high-frequency and high-voltage generator.
The X-ray high-frequency and high-voltage generator be used for X-ray production apparatus, including central control unit 10 and connect the center control
Rectification unit 12, high-frequency inversion unit 14, tube current closed loop circuit 7 and the heater current closed loop circuit 6 of unit 10 processed.
The improvement of the present embodiment is that sampling with high precision circuit is arranged in heater current closed loop circuit.
The output of the high-frequency inversion unit 14 is connected to the load circuit 1 of X-ray production apparatus, the heater current closed loop sample circuit
Setting power DC electricity is converted into for sampling the ac current signal for flowing through the load circuit 1, and by the ac current signal
Pressure signal is exported again to the closed loop feedback control of the heater current closed loop circuit 6 to complete heater current, improves the essence of tube current
Degree and subsequent imaging definition.
In the present embodiment, the load circuit 1 of medical X ray machine is the conventional load circuit of X-ray production apparatus, including bulb Q11
And storage capacitor C17.
Embodiment 2
Referring again to Fig. 1, the present embodiment specifically introduces the heater current closed loop sample circuit.
The heater current closed loop sample circuit be arranged in X-ray production apparatus load circuit 1 and heater current closed loop circuit 6 it
Between, including current detection circuit 2, input filter circuit 3, RMS-DC converter circuit 4 and the voltage follow being successively electrically connected
Output circuit 5.
The current detection circuit 2 sampling flows through the ac current signal of the load circuit 1 and turns the ac current signal
Change ac voltage signal into.The ac voltage signal that the input filter circuit 3 samples the current detection circuit 2 is filtered
And it is input to the RMS-DC converter circuit 4.The ac voltage signal of input is converted into direct current by the RMS-DC converter circuit 4
Signal is pressed, and is exported after filtering.The voltage follow output circuit 5 will be defeated again after d. c. voltage signal progress power amplification
Out to the closed loop feedback control of the heater current closed loop circuit 6 to complete heater current.
Please with reference to Fig. 1 and Fig. 2, in the present embodiment, exchange heater current is converted into the filament electricity of direct current virtual value
It flows closed loop sample circuit to be applied in the heater current closed loop circuit 6 of medical high-frequency high voltage generator, can accurately realize filament electricity
The acquisition of stream reduces sampling error, and then provides the precision of high tube current, guarantees the clarity of last image.
1 load circuit 1 of load circuit of the X-ray production apparatus includes the capacitor the of the first bulb Q11 and the parallel connection of the both ends bulb Q11
Seven C17.The 7th C17 of the capacitor is high-voltage energy storage capacitor.
After the high voltage energy storage filtering that 7th capacitor C17 generates external high frequency high pressure generator, it is connected in parallel on bulb Q11
Both ends, when heater current flows through, central control unit 10 controls the high pressure for providing+KV He-KV, and the electronics of filament surface is in height
It is moved under piezoelectric field, generates tube current, tube current is according to the requirement of national standard GB 9706.3, and error range is within ± 20%.
The current detection circuit 2 includes current transformer, such as the first mutual inductor CT21 and sample resistance, such as third
Resistance R23.The first mutual inductor CT2 primary side is connect with X-ray bulb Q11, and the secondary side of first mutual inductor CT2 is connected, and this takes
Sample resistance.
Bulb Q11 internal filaments first end is connected with the second end of the first mutual inductor CT21, second end and the first mutual inductance
The first end of device CT21, the first end of the 7th capacitor C17 are connected, the third end of the first bulb Q11 and the second of the 7th capacitor C17
End is connected.Filament second end, the first end of the first mutual inductor CT21 of the first end of 7th capacitor C17 and the first bulb Q11
It is connected, second end is connected with the third end of the first bulb Q11.
In the current detection circuit 2, the primary side and filament drive Voltage Series of first mutual inductor CT21 flow through filament
Electric current also flows through first mutual inductor CT21 simultaneously, and first mutual inductor CT21 is according to a certain percentage by the output electric current of filament
Sample the secondary side of mutual inductor.The 3rd resistor R23 of the first mutual inductor CT21 pair side parallel connection is flowed through, is produced on 3rd resistor R23
Raw voltage signal, this voltage signal are output to the input filter circuit 3 again.
The input filter circuit 3 includes resistance capacitance filter circuit and integral filter circuit, in the present embodiment, the integral
Filter circuit is First-order Integral web filter circuit.
Input filter circuit 3 includes the 4th resistance R34, the 5th capacitor R35, the 5th resistance R35 and the 6th capacitor C36.
4th resistance R34 and the 5th capacitor C35 constitute resistance capacitance filter circuit, filter out HF noise signal.This
Amplifier together constitutes with First-order Integral web filter circuit together inside five resistance R35 and the 6th capacitor C36 and the first chip U1.
As shown in Fig. 2, the first of the 4th resistance R34 first end and the first end of the first chip U1, the 5th capacitor C35
End, the second end of the 5th resistance R35 are connected, the third end of the second end of the 4th resistance R34 and the first mutual inductor CT21, third
The second end of resistance R23 is connected.The of the first end of the first end of 5th capacitor C35 and the first chip U1, the 4th resistance R34
One end, the second end of the 5th resistance R35 are connected, and the second end of the 5th capacitor C35 is connected with GND.The of 5th resistance R35
One end is connected with the second end of the 6th capacitor C36, the first end of second end and the first chip U1, the first end of the 4th resistance R34,
The first end of 5th capacitor C35 is connected.The 13rd end, the 14th end of the first end of 6th capacitor C36 and the first chip U1
It is connected, second end is connected with the first end of the 5th resistance R35.
The resistance capacitance filter circuit is for filtering out HF noise signal, the 4th resistance R34 and the sample resistance one end
Connection, the other end input first chip U1, connect the 5th capacitor C35 between the 4th resistance R34 and first chip U1,
5th capacitor C35 ground connection；The integral filter circuit includes the 5th resistance R35 and the 6th capacitor C36 and first chip U1
Inside amplifier unit, the 5th resistance R35 connects the input terminal of the 4th resistance R34 Yu first chip U1, the 5th electricity
Resistance R35 connects the 6th capacitor C36, and the output end of the 6th capacitor C36 connects the inside amplifier unit.
The voltage signal passes through the resistance capacitance filter circuit and First-order Integral network filtering being made of capacitor and resistance
After circuit, it is output to RMS-DC converter circuit 4, such as the input terminal of the first chip U1 in the present embodiment.
The RMS-DC converter circuit 4 receives after external communication signal by internal absolute value circuit, such as active rectification
Ac voltage signal is converted into DC voltage, then is output to voltage follow output circuit 5 by device.The voltage follow output circuit 5
The outside filament current closed-loop circuit 6 is fed back to after amplifying the power of output signal.
The RMS-DC converter circuit 4 includes power supply, the voltage conversion circuit being set in first chip U1, decoupling
Capacitance group and second resistance R42.The enabled current limliting electricity for terminating to external high level that second resistance R42 is the first chip U1
Resistance.
Wherein, which includes the second capacitor C42, third capacitor C43 and the 4th capacitor C44.Power supply electricity
Source includes the first power end and second source end.The second capacitor C42 is the voltage conversion circuit direct current of first chip U1
The filter capacitor of output can effectively filter out high frequency ripple.The third capacitor C43 is the decoupling capacitor of first power end.It should
4th capacitor C44 is the decoupling capacitor at the second source end；The enable end of first chip U1 connects second resistance R42.
It include absolute value circuit and filter circuit inside first chip U1, which can be active rectification
Device.The alternating voltage of different frequency can be converted to direct current virtual value and exported by the absolute value circuit and filter circuit.
Specifically connection relationship is：The of the first end of first chip U1 first end and the 4th resistance R34, the 5th resistance R35
Two ends, the first end of the 5th capacitor C35 are connected；Third end is connected with the 4th end, mutually with the first end of 3rd resistor R23, first
The 4th end of sensor CT21 and GND are connected；5th end is connected with the first end of second resistance R42；6th end and the 9th end phase
Even, then it is connected with the third end of the second end of the second capacitor C42, the second chip U2；The first end at the 8th end and the second capacitor C42
It is connected；Tenth end is connected with the first end of third capacitor C43, power supply -12V；The second end of tenth one end and the 4th capacitor C44,
Power supply+12V is connected；13rd end is connected with the 14th end, then is connected with the first end of the 6th capacitor C36；Second end, the 7th
End, the 12nd end do not connect vacantly；The first end of second capacitor C42 is connected with the 8th end of the first chip U1, second end and first
The 9th end of chip U1, the 6th end of the first chip U1, the third end of the second chip U2 are connected；The first end of third capacitor C43
It is connected with the tenth end of the first chip U1, power supply -12V, second end is connected with the first end of the 4th capacitor C44, GND；4th electricity
The first end for holding C44 is connected with the second end of third capacitor C43, GND, and the tenth one end of second end and the first chip U1, power supply+
12V is connected；The first end of second resistance R42 is connected with the 5th end of the first chip U1, and second end is connected with power supply+12V.
The voltage follow output circuit 5 includes the second chip U2, first capacitor C51 and first resistor R51.
The voltage follow output circuit 5 connects the DC output end of voltage conversion circuit in first chip U1.Second core
Piece U2 is amplifier amplifier, is connected into voltage follower here.The decoupling electricity that first capacitor C51 is the second chip U2 power supply+12V
Hold；First resistor R51 is the second current-limiting resistance that amplifier is output to external filament current closed-loop circuit 6.
The non-inverting input terminal of second chip U2 connects the DC output end of voltage conversion circuit in first chip U1, should
The output of second chip U2 is connected serially to one end of the second current-limiting resistance.The second current-limiting resistance other end connects the heater current and closes
Loop circuit 6.The first offset side of second chip U2 is grounded, and the second offset side of second chip U2 concatenates the first capacitor
The output end of C51, second chip U2 feed back to the inverting input terminal of second chip U2.
The working principle of foregoing circuit is：
After bulb Q11 filament in load circuit 1 flows through electric current, the mutual inductor serial with current detection circuit, mutual inductor
Heater current is collected, with certain proportion output stream over-sampling resistance, is converted into voltage signal, sampling electricity at sampling resistor both ends
Resistance is connected with input filter circuit 3, and voltage signal is long-pending by the resistance and capacitor filter and single order of input filter circuit 3
It is input to direct current RMS-DC converter chip after subnetwork filtering, such as the input terminal of the first chip U1 in the present embodiment.Pass through
Ac voltage signal, is converted into DC voltage by direct current RMS-DC converter chip interior absolute value circuit, such as active rectifier
Afterwards, it is output to rear class voltage follow output circuit 5, then is output to external filament current closed-loop circuit 6.
In the current detection circuit 2, mutual inductor primary side and filament drive Voltage Series flow through the electric current of filament while also flowing
Mutual inductor is crossed, mutual inductor by the output current sample of filament to mutual inductor pair side, flows through mutual inductor pair side according to a certain percentage
Resistance in parallel generates voltage signal on resistance, this voltage signal is output to the input filter circuit 3 of chip again.
After resistance capacitance filter circuit and First-order Integral web filter circuit, be output to direct current has the voltage signal
Valid value conversion chip, such as the first chip U1 in the present embodiment.Conversion chip receives after external communication signal by inside
Ac voltage signal is converted into DC voltage by absolute value circuit, such as active rectifier；It is output to voltage follow output electricity again
Road 5；External filament current closed-loop circuit is given after the power of the amplification output signal of voltage follow output circuit 5.
The heater current closed loop sample circuit and X-ray high-frequency and high-voltage generator of the present embodiment pass through setting sampling electricity
The AC signal of different frequency is directly changed into direct current virtual value by road, solves conventional bridge rectification circuit bring diode
Tube voltage drop, the problem for causing sampling error larger under low voltage condition substantially increase the sampling precision of heater current, simultaneously
The sampling of High-accuracy direct current virtual value improves the precision controlled subsequent closed loop gain, to improve the precision of tube current, protects
Demonstrate,prove the clarity of patient's film making image.And heater current closed loop sample circuit accuracy of the invention is high, circuit structure is simple.
Mode the above is only the implementation of the present invention is not intended to limit the scope of the invention, all to utilize this
Equivalent structure or equivalent flow shift made by description of the invention and accompanying drawing content, it is relevant to be applied directly or indirectly in other
Technical field is included within the scope of the present invention.
Claims (10)
1. a kind of heater current closed loop sample circuit, which is characterized in that setting load circuit and heater current closed loop circuit it
Between, including current detection circuit, input filter circuit, RMS-DC converter circuit and the voltage follow output being successively electrically connected
Circuit,
The current detection circuit is for sampling the ac current signal for flowing through the load circuit and believing the alternating current
Number it is converted into ac voltage signal；
The input filter circuit is for being filtered the ac voltage signal that the current detection circuit samples and defeated
Enter to the RMS-DC converter circuit；
The RMS-DC converter circuit for the ac voltage signal of input to be converted into d. c. voltage signal, and passes through
It is exported after filtering；
The voltage follow output circuit is used to after the d. c. voltage signal is carried out power amplification exported again to the filament
Current closed-loop circuit is to complete the closed loop feedback control of heater current.
2. heater current closed loop sample circuit according to claim 1, which is characterized in that the load circuit is that high frequency is high
The load for pressing generator, including X-ray bulb and the storage capacitor concatenated with the X-ray bulb.
3. heater current closed loop sample circuit according to claim 2, which is characterized in that the current detection circuit includes
Current transformer and sample resistance, the current transformer primary side are connect with the X-ray bulb, the secondary side series connection sampling
Resistance.
4. heater current closed loop sample circuit according to claim 3, which is characterized in that the input filter circuit includes
Resistance capacitance filter circuit and integral filter circuit.
5. heater current closed loop sample circuit according to claim 4, which is characterized in that the resistance capacitance filter circuit
It include the 4th resistance and the 5th capacitor for filtering out HF noise signal, the 4th resistance and described sample resistance one end connect
It connecing, the other end inputs the first chip, connect the 5th capacitor between the 4th resistance and first chip, the described 5th
Capacity earth；The integral filter circuit includes the inside amplifier list of the 5th resistance and the 6th capacitor and first chip
Member, the 5th resistance connect the input terminal of the 4th resistance and first chip, the 5th resistance series connection described the
Six capacitors, the output end connection of the 6th capacitor internal amplifier unit.
6. heater current closed loop sample circuit according to claim 5, which is characterized in that the RMS-DC converter circuit packet
Include power supply, the voltage conversion circuit being set in first chip and decoupling capacitor group.
7. heater current closed loop sample circuit according to claim 6, which is characterized in that the decoupling capacitor group includes the
Two capacitors, third capacitor and the 4th capacitor, the power supply include the first power end and second source end, described second
Capacitor is the filter capacitor of the voltage conversion circuit direct current output of first chip；The third capacitor is first power supply
The decoupling capacitor at end；4th capacitor is the decoupling capacitor at the second source end；The enable end of first chip connects
Current-limiting resistance.
8. heater current closed loop sample circuit according to claim 7, which is characterized in that the voltage follow output circuit
Connect the DC output end of voltage conversion circuit in first chip.
9. heater current closed loop sample circuit according to claim 8, which is characterized in that the voltage follow output circuit
Including the second chip, first capacitor and first resistor, the non-inverting input terminal of second chip is connected in first chip
The DC output end of voltage conversion circuit, the output of second chip are connected serially to one end of the second current-limiting resistance, and described second
The current-limiting resistance other end connects the heater current closed loop circuit；First offset side of second chip is grounded, and described second
Second offset side of chip concatenates the first capacitor, and the output end of second chip feeds back to the reverse phase of second chip
Input terminal.
10. a kind of X-ray high-frequency and high-voltage generator, the rectification including central control unit and the connection central control unit
The output of unit, high-frequency inversion unit and heater current closed loop circuit, the high-frequency inversion unit is connected to the load circuit,
It is characterized in that, further including heater current closed loop sample circuit as described in any one of claims 1-9, the heater current
The ac current signal is converted by closed loop sample circuit for sampling the ac current signal for flowing through the load circuit
Setting power DC voltage signal exports again to the heater current closed loop circuit closed loop feedback control for completing heater current.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810942259.6A CN108834294A (en) | 2018-08-17 | 2018-08-17 | A kind of heater current closed loop sample circuit and X-ray high-frequency and high-voltage generator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810942259.6A CN108834294A (en) | 2018-08-17 | 2018-08-17 | A kind of heater current closed loop sample circuit and X-ray high-frequency and high-voltage generator |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110505743A (en) * | 2019-09-11 | 2019-11-26 | 上海联影医疗科技有限公司 | Tube filament electric current output control system |
| CN111050455A (en) * | 2019-12-04 | 2020-04-21 | 深圳市安健科技股份有限公司 | Bulb tube current automatic calibration method and device, electronic equipment and storage medium |
| CN113438785A (en) * | 2021-06-18 | 2021-09-24 | 浙江国研智能电气有限公司 | Power supply for bulb tube filament of high-voltage X-ray machine |
| CN113839559A (en) * | 2021-08-23 | 2021-12-24 | 安徽明辨电子科技有限公司 | High-voltage floating high-frequency direct-current filament power supply |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110505743A (en) * | 2019-09-11 | 2019-11-26 | 上海联影医疗科技有限公司 | Tube filament electric current output control system |
| CN110505743B (en) * | 2019-09-11 | 2024-05-14 | 上海联影医疗科技股份有限公司 | Bulb tube filament current output control system |
| CN111050455A (en) * | 2019-12-04 | 2020-04-21 | 深圳市安健科技股份有限公司 | Bulb tube current automatic calibration method and device, electronic equipment and storage medium |
| CN111050455B (en) * | 2019-12-04 | 2022-05-06 | 深圳市安健科技股份有限公司 | Bulb tube current automatic calibration method and device, electronic equipment and storage medium |
| CN113438785A (en) * | 2021-06-18 | 2021-09-24 | 浙江国研智能电气有限公司 | Power supply for bulb tube filament of high-voltage X-ray machine |
| CN113839559A (en) * | 2021-08-23 | 2021-12-24 | 安徽明辨电子科技有限公司 | High-voltage floating high-frequency direct-current filament power supply |
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Application publication date: 20181116 |