Current sampling circuit for collecting nuclear radiation detector signals and high voltage power supply

Abstract

The application discloses a current sampling circuit and a high-voltage power supply for collecting a nuclear radiation detector signal. The current sampling circuit is arranged in a nuclear radiation detector comprising the high-voltage power supply. The high-voltage power supply comprises a transformer assembly. The current sampling circuit comprises a sampling resistance-adjustable collecting unit and a resistance adjusting unit. The sampling resistance-adjustable collecting unit is connected to the secondary side of the transformer assembly. The sampling resistance-adjustable collecting unit is used to collect the voltage of the secondary side of the transformer assembly and output the collected voltage. The resistance adjusting unit is connected to the sampling resistance-adjustable collecting unit. The resistance adjusting unit is used to control the sampling resistance of the sampling resistance-adjustable collecting unit to dynamically change until stable according to the first voltage. The current of the nuclear radiation detector is the ratio between the target voltage and the target resistance. The target resistance is the sampling resistance of the sampling resistance-adjustable collecting unit after the resistance is adjusted to stable. The target voltage is the voltage collected by the sampling resistance-adjustable collecting unit under the target resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear radiation detector measurement, and in particular to a current sampling circuit for collecting nuclear radiation detector signals and a high-voltage power supply. BACKGROUND

[0002] In the field of nuclear radiation detector measurement, the nuclear instrument system of a nuclear power plant is one of the most critical systems of a reactor, which monitors the neutron fluence rate level in the reactor and thus the reactor power by using out-of-core nuclear measurement detectors distributed around the reactor pressure vessel. When detecting the neutron fluence rate level, a high-voltage power supply needs to be provided for the nuclear radiation detector to ionize gas molecules, and the current of the nuclear radiation detector needs to be measured.

[0003] However, the high-voltage power supply device of the nuclear radiation detector generally does not have a current sampling function, so an independent current measurement device needs to be used to measure the current of the nuclear radiation detector. SUMMARY

[0004] The present application aims to provide a current sampling circuit for collecting nuclear radiation detector signals and a high-voltage power supply, which can solve the problem of needing to use an independent current measurement device to measure the current of the nuclear radiation detector.

[0005] In a first aspect, an embodiment of the present application provides a current sampling circuit, which is arranged in a nuclear radiation detector including a high-voltage power supply, the high-voltage power supply including a transformer assembly, and the current sampling circuit including:

[0006] a sampling resistance adjustable acquisition unit connected to the secondary side of the transformer assembly, the sampling resistance adjustable acquisition unit being configured to acquire the voltage of the secondary side of the transformer assembly and output the acquired voltage;

[0007] a resistance adjusting unit connected to the sampling resistance adjustable acquisition unit, the resistance adjusting unit being configured to control the sampling resistance of the sampling resistance adjustable acquisition unit to dynamically change according to a first voltage until the sampling resistance of the sampling resistance adjustable acquisition unit is adjusted to be stable, the first voltage being the voltage acquired by the sampling resistance adjustable acquisition unit;

[0008] wherein the current of the nuclear radiation detector is a ratio between a target voltage and a target resistance, the target resistance being the sampling resistance of the sampling resistance adjustable acquisition unit when the sampling resistance is adjusted to be stable, and the target voltage being the voltage acquired by the sampling resistance adjustable acquisition unit at the target resistance.

[0009] According to some embodiments of the present application, the resistance adjusting unit includes:

[0010] a window comparison subunit, the sampling resistance adjustable acquisition unit is connected to the window comparison subunit, the window comparison subunit is used to confirm whether the first voltage is in a preset voltage range, and if the first voltage is not in the preset voltage range, a control signal is outputted;

[0011] a counting subunit, the window comparison subunit is connected to the counting subunit, and the counting subunit is used to count under the condition of receiving the control signal;

[0012] a decoding subunit, the counting subunit is connected to the decoding subunit, the decoding subunit is connected to the sampling resistance adjustable acquisition unit, and the decoding subunit is used to control the sampling resistance value change of the sampling resistance adjustable acquisition unit according to the counting value of the counting subunit.

[0013] According to some embodiments of the present application, the window comparison subunit comprises:

[0014] a first comparator, a first input end of the first comparator is connected to the sampling resistance adjustable acquisition unit, a second input end of the first comparator is used to input an upper limit value of voltage of the preset voltage range, an output end of the first comparator is connected to a first input end of the counting subunit, and the first comparator is used to control the counting subunit to count according to the comparison result of the upper limit value of voltage and the first voltage;

[0015] a second comparator, a first input end of the second comparator is used to input a lower limit value of voltage of the preset voltage range, a second input end of the second comparator is connected to the sampling resistance adjustable acquisition unit, and an output end of the second comparator is connected to a second input end of the counting subunit, and the second comparator is used to control the counting subunit to count according to the comparison result of the lower limit value of voltage and the first voltage.

[0016] According to some embodiments of the present application, the sampling resistance adjustable acquisition unit comprises:

[0017] a plurality of sampling resistors, one end of each of the plurality of sampling resistors is connected to the secondary side of the transformer assembly;

[0018] a switch subunit, the other end of each of the plurality of sampling resistors is connected to the switch subunit, the resistance adjusting unit is connected to the switch subunit, and the switch subunit is used to control any one of the plurality of sampling resistors to work,

[0019] wherein the sampling resistance value of the sampling resistance adjustable acquisition unit is the resistance value of the sampling resistor in work.

[0020] According to some embodiments of the present application, further comprising:

[0021] An absolute value unit, the sampling resistance adjustable acquisition unit is connected with the absolute value unit, the absolute value unit is connected with the resistance adjustment unit, and the absolute value unit is used for outputting the first voltage after absolute value processing to the resistance adjustment unit.

[0022] According to some embodiments of the application, the absolute value unit comprises:

[0023] A reverse amplification subunit, the reverse amplification subunit is connected with the sampling resistance adjustable acquisition unit, and the reverse amplification subunit is used for obtaining a second voltage according to the first voltage when the first voltage is a positive voltage, and outputting the second voltage, the second voltage being negative twice of the first voltage.

[0024] A reverse addition subunit, the reverse addition subunit is connected with the reverse amplification subunit, and the reverse addition subunit is connected with the sampling resistance adjustable acquisition unit, and the reverse addition subunit is used for summing the first voltage and the second voltage to obtain a sum voltage when the first voltage is a positive voltage, and outputting the sum voltage after reverse processing to the resistance adjustment unit, and outputting the first voltage after reverse processing to the resistance adjustment unit when the first voltage is a negative voltage.

[0025] According to some embodiments of the application, the reverse amplification subunit comprises:

[0026] A first resistor, one end of the first resistor is connected with the sampling resistance adjustable acquisition unit;

[0027] A first operational amplifier, the other end of the first resistor is connected with the inverting input terminal of the first operational amplifier, and the non-inverting input terminal of the first operational amplifier is grounded;

[0028] A first diode, the positive electrode of the first diode is connected with the output terminal of the first operational amplifier, and the negative electrode of the first diode is connected with the inverting input terminal of the first operational amplifier;

[0029] A second diode, the negative electrode of the second diode is connected with the output terminal of the first operational amplifier;

[0030] A second resistor, one end of the second resistor is connected with the positive electrode of the second diode, and the other end of the second resistor is connected with the inverting input terminal of the first operational amplifier;

[0031] A third resistor, one end of the third resistor is connected with the positive electrode of the second diode, and the other end of the third resistor is connected with the reverse addition subunit.

[0032] According to some embodiments of the application, the reverse addition subunit comprises:

[0033] a second operational amplifier, wherein the inverting input terminal of the second operational amplifier is connected to the reverse amplification subunit, the non-inverting input terminal of the second operational amplifier is connected to the ground, and the output terminal of the second operational amplifier is connected to the resistance adjusting unit;

[0034] a fourth resistor, wherein one end of the fourth resistor is connected to the sampling resistance adjustable acquisition unit, and the other end of the fourth resistor is connected to the inverting input terminal of the second operational amplifier;

[0035] a fifth resistor, wherein one end of the fifth resistor is connected to the inverting input terminal of the second operational amplifier, and the other end of the fifth resistor is connected to the output terminal of the second operational amplifier.

[0036] According to some embodiments of the present application, the current sampling circuit further comprises:

[0037] a high-voltage sampling unit, wherein the high-voltage sampling unit is connected to the second operational amplifier, the high-voltage sampling unit is used to acquire a third voltage, and the high-voltage sampling unit outputs the third voltage to the inverting input terminal of the second operational amplifier, so as to correct the first voltage by using the third voltage, and the third voltage is the output terminal voltage of the secondary side of the transformer assembly.

[0038] According to some embodiments of the present application, the current sampling circuit further comprises:

[0039] a triode, wherein the collector of the triode is used to be connected to a low-voltage power supply, and the emitter of the triode is connected to the primary side of the transformer assembly.

[0040] a first error amplifier, wherein the non-inverting input terminal of the first error amplifier is used to input a preset target voltage, the inverting input terminal of the first error amplifier is connected to the high-voltage sampling unit, and the output terminal of the first error amplifier is connected to the base of the triode, the first error amplifier is used to adjust the base voltage of the triode according to the error between the third voltage and the preset target voltage, so as to adjust the input voltage of the primary side of the transformer assembly, and make the output terminal of the secondary side of the transformer assembly stably output the preset target voltage.

[0041] In the second aspect, the embodiments of the present application provide a high-voltage power supply, comprising the current sampling circuit as described above.

[0042] In the embodiment of the present application, the voltage of the secondary side of the voltage transformation assembly is collected by the sampling resistance adjustable collection unit, the sampling resistance of the sampling resistance adjustable collection unit is dynamically changed by the resistance adjusting unit according to the voltage collected by the sampling resistance adjustable collection unit, until the sampling resistance of the sampling resistance adjustable collection unit is adjusted to be stable, the sampling resistance of the sampling resistance adjustable collection unit under the stable resistance is obtained according to the voltage collected by the sampling resistance adjustable collection unit under the stable resistance, and the current of the nuclear radiation detector is calculated according to the voltage collected by the sampling resistance adjustable collection unit under the target resistance. Compared with the traditional nuclear radiation detector measurement technology, the current of the nuclear radiation detector can be sampled with high precision without using an independent current measurement device.

[0043] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0044] The present application will be further described below in conjunction with the drawings and embodiments, wherein:

[0045] Figure 1 The functional block diagram of the embodiment of the current sampling circuit provided by the present application is shown in the figure;

[0046] Figure 2 The circuit schematic diagram of the sampling resistance adjustable collection unit and the resistance adjusting unit in the embodiment of the current sampling circuit provided by the present application is shown in the figure;

[0047] Figure 3 The circuit schematic diagram of the absolute value unit in the embodiment of the current sampling circuit provided by the present application is shown in the figure;

[0048] Figure 4 The circuit schematic diagram of the first error amplifier and the first current limiting unit in the embodiment of the current sampling circuit provided by the present application is shown in the figure;

[0049] Figure 5 The circuit schematic diagram of the voltage doubling rectification unit and the filtering unit in the embodiment of the current sampling circuit provided by the present application is shown in the figure.

[0050] Reference signs:

[0051] Window comparison subunit 100, counting subunit 110, decoding subunit 120, switching subunit 130, absolute value unit 140, reverse amplification subunit 150, reverse addition subunit 160, high voltage sampling unit 170, second current limiting unit 180, first current limiting unit 190, voltage doubling rectification unit 200, filtering unit 210, proportional amplification unit 220, oscillator 230. DETAILED DESCRIPTION

[0052] Embodiments of the present application are described below in detail with reference to the accompanying drawings, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary only, and are used only for the purpose of explaining the present application, and are not to be understood as limiting the present application.

[0053] In the description of the present application, it needs to be understood that the orientation description, such as the orientation or position relationship indicated by up, down, etc. is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and is not to indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0054] In the description of the present application, multiple refers to more than two. If there is a description of first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0055] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0056] The following refers to Figures 1 to 5 A current sampling circuit and a high-voltage power supply for collecting a nuclear radiation detector signal are described according to an embodiment of the present application.

[0057] An embodiment of the present application provides a current sampling circuit arranged in a nuclear radiation detector including a high-voltage power supply, the high-voltage power supply including a transformer assembly T1, the current sampling circuit including:

[0058] A sampling resistance adjustable acquisition unit, the sampling resistance adjustable acquisition unit being connected with the secondary side of the transformer assembly T1, the sampling resistance adjustable acquisition unit being used to acquire the voltage of the secondary side of the transformer assembly T1 and output the acquired voltage;

[0059] A resistance adjusting unit, the resistance adjusting unit being connected with the sampling resistance adjustable acquisition unit, the resistance adjusting unit being used to control the sampling resistance of the sampling resistance adjustable acquisition unit to dynamically change according to a first voltage until the sampling resistance of the sampling resistance adjustable acquisition unit is adjusted to be stable, the first voltage being the voltage acquired by the sampling resistance adjustable acquisition unit;

[0060] The current of the nuclear radiation detector is a ratio of the target voltage Vsi and a target resistance value, the target resistance value is the sampling resistance value adjusted by the sampling resistance adjustable acquisition unit to be stable, and the target voltage Vsi is the voltage collected by the sampling resistance adjustable acquisition unit at the target resistance value.

[0061] In the embodiment of the present application, the voltage of the secondary side of the voltage transformation assembly T1 is collected by the sampling resistance adjustable acquisition unit, the sampling resistance value of the sampling resistance adjustable acquisition unit is dynamically changed by the resistance value adjusting unit according to the voltage collected by the sampling resistance adjustable acquisition unit until the sampling resistance value of the sampling resistance adjustable acquisition unit is adjusted to be stable, and the current of the nuclear radiation detector can be calculated according to the sampling resistance value of the sampling resistance adjustable acquisition unit adjusted to be stable and the voltage collected by the sampling resistance adjustable acquisition unit at the target resistance value. Compared with the traditional nuclear radiation detector measurement technology, the embodiment of the present application can sample the current of the nuclear radiation detector with high precision without using an independent current measurement device.

[0062] The voltage transformation assembly T1 includes a transformer. The sampling resistance adjustable acquisition unit can use a variable resistor to collect the voltage of the secondary side of the voltage transformation assembly T1. The variable resistor can dynamically change the sampling resistance value under the control of the resistance value adjusting unit, so as to change the sampling range.

[0063] It should be noted that the resistance value adjusting unit can use an MCU, and the MCU controls the sampling resistance value of the sampling resistance adjustable acquisition unit to dynamically change according to the first voltage until the first voltage is within the working voltage range of the sampling resistance adjustable acquisition unit and the sampling resistance value is stable. This can improve the sampling precision of the sampling resistance adjustable acquisition unit and avoid burning out of the sampling resistance adjustable acquisition unit due to the first voltage being too large.

[0064] As shown in the embodiment of the present application, Figure 1 The resistance value adjusting unit includes:

[0065] The window comparison subunit 100 is connected to the sampling resistance adjustable acquisition unit, and the window comparison subunit 100 is configured to determine whether the first voltage is within a preset voltage range, and output a control signal if the first voltage is not within the preset voltage range.

[0066] The counting subunit 110 is connected to the window comparison subunit 100, and the counting subunit 110 is configured to count when the control signal is received.

[0067] The decoding subunit 120 is connected to the counting subunit 110 and the sampling resistance adjustable acquisition unit, and the decoding subunit 120 is configured to control the sampling resistance value of the sampling resistance adjustable acquisition unit to change according to the count value of the counting subunit 110.

[0068] In this embodiment, the preset voltage range is the working voltage range of the sampling resistance adjustable acquisition unit. The window comparison subunit 100 judges whether the first voltage is within the preset voltage range. If the first voltage is not within the preset voltage range, a control signal is output to the counting subunit 110. The counting subunit 110 counts according to the control signal, so that the count value changes. The decoding subunit 120 controls the sampling resistance of the sampling resistance adjustable acquisition unit to change according to the count value, so as to realize the adjustment of the sampling resistance. When the first voltage changes with the change of the sampling resistance until it is within the preset voltage range, the window comparison subunit 100 does not output the control signal, and the count value of the counting subunit 110 does not change. Therefore, the decoding subunit 120 does not adjust the count value to control the sampling resistance of the sampling resistance adjustable acquisition unit, and the sampling resistance is stable.

[0069] The window comparison subunit 100 can use a window comparator. The upper threshold of the window comparator is the upper limit value of the preset voltage range, and the lower threshold of the window comparator is the lower limit value of the preset voltage range. Whether the first voltage is between the upper threshold and the lower threshold is judged by the window comparator.

[0070] The counting subunit 110 can control the delay time of each change of the sampling resistance by counting length. After waiting for the delay time of the change of the sampling resistance once, the decoding is performed by the decoding subunit 120 to collect the current under the corresponding sampling range.

[0071] It should be noted that, as shown in Figure 2 The counting subunit 110 includes a counter U1. The output end of the window comparison subunit 100 is connected to the input end of the counter U1, and the output end of the counter U1 is connected to the input end of the decoding subunit 120. The counter U1 counts according to the control signal output by the window comparison subunit 100 and outputs the count value to the decoding subunit 120 through the output end.

[0072] As shown in Figure 2 The counter U1 has multiple output ends, and the multiple output ends of the counter U1 are connected to the decoding subunit 120. The count value is output to the decoding subunit 120 through the multiple output ends. The counting subunit 110 further includes an AND gate module U3. The AND gate module U3 has multiple input ends, and the multiple output ends of the counter U1 are connected to the multiple input ends of the AND gate module U3. The output end of the AND gate module U3 is connected to the reset end of the counter U1. The counter U1 counts between multiple count values. When the multiple output ends of the counter U1 are all high, it indicates that each count value has been counted. The output end of the AND gate module U3 outputs a high level to the reset end of the counter U1, so that the counter U1 is reset and starts counting again. The AND gate module U3 includes an AND gate logic circuit. The model of the counter U1 can be SN74HC193D.

[0073] The decoding subunit 120 can employ a decoder U2. The model of the decoder U2 can be SN74HC138D.

[0074] As shown in FIG. 1, the window comparison subunit 100 includes: Figure 2

[0075] The first comparator A1 has a non-inverting input end connected to the sampling resistance adjustable sampling unit, an inverting input end for inputting an upper limit value of a preset voltage range, and an output end connected to a first input end of the counting subunit 110. The first comparator A1 is configured to control the counting subunit 110 to count according to a comparison result of the upper limit value of the preset voltage range and the first voltage.

[0076] The second comparator A2 has a non-inverting input end for inputting a lower limit value of the preset voltage range, an inverting input end connected to the sampling resistance adjustable sampling unit, and an output end connected to a second input end of the counting subunit 110. The second comparator A2 is configured to control the counting subunit 110 to count according to a comparison result of the lower limit value of the preset voltage range and the first voltage.

[0077] In this embodiment, the first comparator A1 is configured to compare the upper limit value of the preset voltage range and the first voltage. When the first voltage is greater than the upper limit value of the voltage, the first comparator A1 outputs a high level to the counting subunit 110, so that the counting subunit 110 counts up. The second comparator A2 is configured to compare the lower limit value of the preset voltage range and the first voltage. When the lower limit value of the voltage is greater than the lower limit value of the voltage, the second comparator A2 outputs a high level to the counting subunit 110, so that the counting subunit 110 counts down.

[0078] As shown in FIG. 1, the sampling resistance adjustable sampling unit includes: Figure 1

[0079] The sampling resistance adjustable sampling unit includes a plurality of sampling resistors Rs, one end of each of the plurality of sampling resistors Rs being connected to a secondary side of a transformer assembly T1.

[0080] The switching subunit 130 has the other end of each of the plurality of sampling resistors Rs connected thereto, and a resistance adjusting unit connected thereto. The switching subunit 130 is configured to control any one of the plurality of sampling resistors Rs to work,

[0081] The sampling resistance of the sampling resistance adjustable sampling unit is the resistance of the sampling resistor Rs that is working.

[0082] ​​In this embodiment, the plurality of sampling resistors Rs have different resistance values, and the plurality of sampling resistors Rs correspond to a plurality of ranges. The resistance value adjusting unit can control the switch sub-unit 130 to conduct any one of the plurality of sampling resistors Rs, so that the conducted sampling resistor works, and the resistance value of the working sampling resistor is the sampling resistance value of the sampling resistance adjustable collection unit.

[0083] As shown in Figure 2 The switch sub-unit 130 includes a plurality of relays, and the plurality of relays correspond one-to-one to the plurality of sampling resistors Rs. The plurality of relays are connected to the plurality of sampling resistors Rs. The resistance value adjusting unit is connected to the control end of the plurality of relays, and can control the on-off state of the plurality of relays, thereby controlling any one of the plurality of sampling resistors Rs to work.

[0084] In an embodiment of the present application, the sampling resistance adjustable collection unit further comprises:

[0085] The absolute value unit 140 is connected to the resistance value adjusting unit, and is configured to perform absolute value processing on the first voltage and output the absolute value processed first voltage to the resistance value adjusting unit.

[0086] In this embodiment, the absolute value unit 140 can perform absolute value processing on the first voltage output by the sampling resistance adjustable collection unit, and output the absolute value processed first voltage, i.e., the target voltage Vsi.

[0087] The absolute value unit 140 can be a full-wave rectifier circuit.

[0088] In an embodiment of the present application, as shown in Figures 1 to 2 The absolute value unit 140 includes:

[0089] The reverse amplification sub-unit 150 is connected to the sampling resistance adjustable collection unit, and is configured to obtain a second voltage from the first voltage when the first voltage is a positive voltage, and output the second voltage, the second voltage being negative twice the first voltage.

[0090] The reverse addition sub-unit 160 is connected to the reverse amplification sub-unit 150 and the sampling resistance adjustable collection unit, and is configured to sum the first voltage and the second voltage to obtain a sum voltage when the first voltage is a positive voltage, and output the sum voltage after reverse processing to the resistance value adjusting unit, and perform reverse processing on the first voltage and output the reverse processed first voltage to the resistance value adjusting unit when the first voltage is a negative voltage.

[0091] In the embodiment, when the first voltage output by the sampling resistance-adjustable acquisition unit is a positive voltage, the reverse amplification sub-unit 150 obtains a second voltage from the first voltage and outputs the second voltage, the second voltage being negative twice the first voltage, the reverse addition sub-unit 160 obtains a summation voltage by summing the first voltage and the second voltage, and then outputs the summation voltage after reverse processing, so that the first voltage remains unchanged, and the voltage output by the reverse addition sub-unit 160 to the resistance-adjusting unit is still the first voltage. When the first voltage output by the sampling resistance-adjustable acquisition unit is a negative voltage, the reverse amplification sub-unit 150 does not process the first voltage, the voltage output by the reverse amplification sub-unit 150 is 0, the reverse addition sub-unit 160 outputs the first voltage after reverse processing, so that the first voltage becomes a positive voltage, and the voltage output by the reverse addition sub-unit 160 to the resistance-adjusting unit is the converted first voltage.

[0092] As shown in the embodiment of the present application, Figure 3 The reverse amplification sub-unit 150 includes:

[0093] The first resistance R1 has one end connected to the sampling resistance-adjustable acquisition unit.

[0094] The first operational amplifier A3 has its inverting input end connected to the other end of the first resistance R1, and its non-inverting input end grounded.

[0095] The first diode D1 has its positive electrode connected to the output end of the first operational amplifier A3, and its negative electrode connected to the inverting input end of the first operational amplifier A3.

[0096] The second diode D2 has its negative electrode connected to the output end of the first operational amplifier A3.

[0097] The second resistance R2 has one end connected to the positive electrode of the second diode D2, and the other end connected to the inverting input end of the first operational amplifier A3.

[0098] The third resistance R4 has one end connected to the positive electrode of the second diode D2, and the other end connected to the reverse addition sub-unit 160.

[0099] In this embodiment, when the first voltage is positive, the first diode D1 is off and the second diode D2 is on. The first resistor R1, the second resistor R2, the third resistor R4, and the first operational amplifier A3 collectively amplify the first voltage. By setting the ratio of the first resistor R1, the second resistor R2, and the third resistor R4, the first voltage is amplified by a factor of two and inverted to obtain the second voltage. The second voltage is output from the third resistor R4 to the inverting adder subunit 160. When the first voltage is negative, the first diode D1 is on and the second diode D2 is off. At this time, the first operational amplifier A3 clamps the voltage at one end of the second resistor R2 to 0. Under the feedback effect of the inverting adder subunit 160, the voltage at one end of the third resistor R4 is 0. Therefore, no current flows through the inverting amplification subunit 150, and it does not function.

[0100] One embodiment of this application, such as Figure 3 As shown, the inverse adder subunit 160 includes:

[0101] The second operational amplifier A4 has an inverting amplification subunit 150 connected to its inverting input terminal, a non-inverting input terminal grounded, and an output terminal connected to a resistance adjustment unit.

[0102] The fourth resistor R3 is connected at one end to the sampling resistance adjustable acquisition unit, and at the other end to the inverting input terminal of the second operational amplifier A4.

[0103] The fifth resistor R5 is connected at one end to the inverting input of the second operational amplifier A4, and at the other end to the output of the second operational amplifier A4.

[0104] In this embodiment, by setting the ratio of the fourth resistor R3 and the fifth resistor R5, the second operational amplifier A4, the fourth resistor R3, and the fifth resistor R5 together act as an inverse resistor. When the first voltage is positive, the inverse adder subunit 160 sums the first voltage and the second voltage to obtain a summed voltage, then inverses the summed voltage and outputs it to the resistance adjustment unit. When the first voltage is negative, the first voltage is inverted and output to the resistance adjustment unit.

[0105] One embodiment of this application, such as Figure 1 As shown, it also includes:

[0106] High voltage sampling unit 170 is connected to the second operational amplifier A4. The high voltage sampling unit 170 is used to acquire the third voltage HV and output it to the inverting input terminal of the second operational amplifier A4, thereby using the third voltage HV to correct the first voltage. The third voltage HV is the output terminal voltage of the secondary side of the transformer component T1.

[0107] In the embodiment of the present application, the sampling resistor connected to the secondary side of the transformer assembly T1 consumes current, so the output voltage of the secondary side of the transformer assembly T1 is used to correct the first voltage, so that the target voltage Vsi obtained subsequently is more accurate, and thus the result of calculating the current of the nuclear radiation detector by using the target voltage Vsi is more accurate.

[0108] The output end of the secondary side of the transformer assembly T1 is used to connect a load.

[0109] As shown in Figure 4 , the high-voltage sampling unit 170 includes a voltage follower A5 connected to the output end of the secondary side of the transformer assembly T1, the voltage follower A5 is connected to the inverting input end of the second operational amplifier A4, and the voltage follower A5 outputs a third voltage HV to the inverting input end of the second operational amplifier A4.

[0110] In an embodiment of the present application, as shown in Figure 1 , the present application further comprises:

[0111] A triode Q1, the collector of the triode Q1 is used to connect a low-voltage power supply, and the emitter of the triode Q1 is connected to the primary side of the transformer assembly T1.

[0112] A first error amplifier A6, as shown in Figure 4 , the non-inverting input end of the first error amplifier A6 is used to input a preset target voltage Vset, the inverting input end of the first error amplifier A6 is connected to the high-voltage sampling unit 170, and the output end of the first error amplifier A6 is connected to the base of the triode Q1. The first error amplifier A6 is used to adjust the base voltage of the triode Q1 according to the error between the third voltage HV and the preset target voltage Vset, so as to adjust the input voltage of the primary side of the transformer assembly T1, so that the output end of the secondary side of the transformer assembly T1 stably outputs the preset target voltage Vset.

[0113] In the embodiment, the low-voltage power supply provides voltage for the primary side of the transformer assembly T1 through the triode Q1, and the first error amplifier A6 adjusts the base voltage of the triode Q1 according to the error between the third voltage HV and the preset target voltage Vset, so as to adjust the input voltage of the primary side of the transformer assembly T1, so that the output end of the secondary side of the transformer assembly T1 stably outputs the preset target voltage Vset.

[0114] The collector of the triode Q1 is connected to the low-voltage power supply through a second current limiting unit 180, and the second current limiting unit 180 can play a current limiting protection role. The second current limiting unit 180 can adopt a MOS tube current limiting protection circuit.

[0115] In an embodiment of the present application, as shown in Figure 1As shown in the figure, the high-voltage power supply further comprises:

[0116] The proportional amplification unit 220 comprises a third operational amplifier A8, the output end of the first error amplifier A6 is connected to the non-inverting input end of the third operational amplifier A8, and the output end of the third operational amplifier A8 is connected to the base of the triode Q1.

[0117] In this embodiment, the third operational amplifier A8 inputs the voltage of the first error amplifier A6 after gain adjustment to the base of the triode Q1, so as to adjust the input voltage of the primary side of the transformer assembly T1 by controlling the triode Q1.

[0118] As shown in the figure, Figure 1 As shown in the figure, the high-voltage power supply further comprises:

[0119] The first current limiting unit 190 has an input end connected to the output end of the second operational amplifier A4, and an output end connected to the non-inverting input end of the third operational amplifier A8.

[0120] In this embodiment, the output end of the second operational amplifier A4 is connected to the non-inverting input end of the third operational amplifier A8 through the first current limiting unit 190, and the first current limiting unit 190 plays a role of short-circuit current protection.

[0121] As shown in the figure, Figure 4 The first current limiting unit 190 comprises a second error amplifier A7 and a third diode D3, the non-inverting input end of the second error amplifier A7 is connected to the absolute value unit 140, the inverting input end of the second error amplifier A7 is used for inputting a preset reference voltage, the output end of the second error amplifier A7 is connected to the negative electrode of the third diode D3, and the positive electrode of the third diode D3 is connected to the non-inverting input end of the second error amplifier A7. The second error amplifier A7 calculates the error between the target voltage Vsi output by the absolute value unit 140 and the preset reference voltage, and outputs to the third diode D3. If the error between the target voltage Vsi and the preset reference voltage is large, the output end voltage of the second error amplifier A7 breaks through the third diode D3, and the output end voltage of the second error amplifier A7 is output to the non-inverting input end of the third operational amplifier A8, and then output to the base of the triode Q1 through the gain adjustment of the third operational amplifier A8, so as to adjust the input voltage of the primary side of the transformer assembly T1 by controlling the triode Q1, thereby reducing the output current of the transformer assembly T1.

[0122] As shown in the figure, Figure 1 As shown in the figure, the high-voltage power supply further comprises:

[0123] The voltage doubling rectification unit 200 is connected to the secondary side of the transformer assembly T1.

[0124] In this embodiment, the voltage doubling rectifier unit 200 can multiply the voltage of the secondary side of the transformer assembly T1 and output.

[0125] As shown in Figure 5 , the voltage doubling rectifier unit 200 includes a first capacitor C5, a second capacitor C6, a fourth diode D4, and a fifth diode D5. One end of the secondary side of the transformer assembly T1 is connected to one end of the first capacitor C5, the other end of the first capacitor C5 is connected to the positive electrode of the fifth diode D5, the other end of the secondary side of the transformer assembly T1 is connected to the positive electrode of the fourth diode D4, the negative electrode of the fourth diode D4 is connected to the positive electrode of the fifth diode D5, the negative electrode of the fifth diode D5 is connected to one end of the second capacitor C6, and the other end of the second capacitor C6 is connected to the other end of the secondary side of the transformer assembly T1.

[0126] In an embodiment of the present application, as shown in Figure 1 , the high-voltage power supply further includes:

[0127] A filter unit 210 is connected to the voltage doubling rectifier unit 200.

[0128] In this embodiment, the filter unit 210 can filter the high-voltage signal output by the voltage doubling rectifier unit 200 and output.

[0129] As shown in Figure 5 , the filter unit 210 uses a high-voltage low-pass filter circuit, which includes a sixth resistor R17, a seventh resistor R18, an eighth resistor R19, a third capacitor C7, and a fourth capacitor C8. One end of the second capacitor C6 is connected to one end of the sixth resistor R17, the other end of the sixth resistor R17 is connected to one end of the third capacitor C7, and the other end of the second capacitor C6 is connected to the other end of the third capacitor C7. One end of the third capacitor C7 is connected to one end of the seventh resistor R18, the other end of the seventh resistor R18 is connected to one end of the fourth capacitor C8, and the other end of the fourth capacitor C8 is connected to the other end of the third capacitor C7. The other end of the seventh resistor R18 is connected to one end of the eighth resistor R19, and the other end of the eighth resistor R19 is used to output the filtered high-voltage signal, which is the third voltage HV.

[0130] In an embodiment of the present application, as shown in Figure 1 , the high-voltage power supply further includes:

[0131] A chopper circuit is connected to the primary side of the transformer assembly T1.

[0132] In this embodiment, the chopper circuit chops the voltage of the primary side of the transformer assembly T1 to convert it into a pulse voltage.

[0133] The chopper circuit comprises an oscillator 230 and a switch tube Q2, an input end of the switch tube Q2 is connected to a primary side of the transformer assembly T1, an output end of the switch tube Q2 is grounded, and an output end of the oscillator 230 is connected to a control end of the switch tube Q2. The switch tube Q2 can be a MOS tube. The oscillator 230 can be a NE555D.

[0134] In addition, the application further provides a high-voltage power supply comprising the current sampling circuit.

[0135] The nuclear radiation detector provided by the application can realize the processes realized by the circuit embodiments and achieve the same beneficial effects. To avoid repetition, details are not described herein.

[0136] The application is described in detail above in combination with the drawings, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application.

Claims

1. A current sampling circuit for acquiring signals from a nuclear radiation detector, characterized in that, The current sampling circuit is located within a nuclear radiation detector that includes a high-voltage power supply, the high-voltage power supply comprising a transformer assembly, and the detector itself comprising: An adjustable sampling resistance acquisition unit is connected to the secondary side of the transformer assembly. The adjustable sampling resistance acquisition unit is used to acquire the voltage on the secondary side of the transformer assembly and output the acquired voltage. A resistance adjustment unit is connected to the adjustable sampling resistance acquisition unit. The resistance adjustment unit is used to control the dynamic change of the sampling resistance of the adjustable sampling resistance acquisition unit according to the first voltage, until the sampling resistance of the adjustable sampling resistance acquisition unit is adjusted to a stable value. The first voltage is the voltage acquired by the adjustable sampling resistance acquisition unit. Wherein, the current of the nuclear radiation detector is the ratio between the target voltage and the target resistance, the target resistance is the sampling resistance value that the adjustable sampling resistance acquisition unit adjusts to a stable value, and the target voltage is the voltage acquired by the adjustable sampling resistance acquisition unit at the target resistance value; The resistance adjustment unit includes: A window comparison subunit is connected to the adjustable sampling resistance acquisition unit. The window comparison subunit is used to confirm whether the first voltage is within a preset voltage range. If the first voltage is not within the preset voltage range, a control signal is output. A counting subunit is provided, and the window comparison subunit is connected to the counting subunit. The counting subunit is used to perform counting upon receiving the control signal. A decoding subunit is provided, the counting subunit is connected to the decoding subunit, the decoding subunit is connected to the adjustable sampling resistance acquisition unit, and the decoding subunit is used to control the change of the sampling resistance of the adjustable sampling resistance acquisition unit according to the count value of the counting subunit.

2. The current sampling circuit according to claim 1, characterized in that, The window comparison subunit includes: The first comparator has an adjustable sampling resistance acquisition unit connected to its first input terminal. The second input terminal of the first comparator is used to input the upper limit value of the preset voltage range. The output terminal of the first comparator is connected to the first input terminal of the counting subunit. The first comparator is used to control the counting subunit to count based on the comparison result between the upper limit value and the first voltage. The second comparator has a first input terminal for inputting the lower limit value of the preset voltage range, a second input terminal connected to the sampling resistance adjustable acquisition unit, and an output terminal connected to the second input terminal of the counting subunit. The second comparator is used to control the counting subunit to count based on the comparison result between the lower limit value and the first voltage.

3. The current sampling circuit according to claim 1, characterized in that, The adjustable sampling resistance acquisition unit includes: Multiple sampling resistors, one end of each of the multiple sampling resistors being connected to the secondary side of the transformer assembly; A switching subunit is included, with the other ends of each of the plurality of sampling resistors connected to it. A resistance adjustment unit is also connected to the switching subunit. The switching subunit is used to control the operation of any one of the plurality of sampling resistors. The sampling resistance of the adjustable sampling unit is the resistance value of the sampling resistor in operation.

4. The current sampling circuit according to claim 1, characterized in that, Also includes: An absolute value unit is provided, wherein the sampling resistance adjustable acquisition unit is connected to the absolute value unit, and the absolute value unit is connected to the resistance adjustment unit. The absolute value unit is used to process the first voltage into absolute values ​​and then output it to the resistance adjustment unit.

5. The current sampling circuit according to claim 4, characterized in that, The absolute value unit includes: An inverting amplification subunit is connected to the adjustable sampling resistance acquisition unit. The inverting amplification subunit is used to obtain a second voltage based on the first voltage when the first voltage is a positive voltage, and output the second voltage, which is negative twice the first voltage. The inverting addition subunit is connected to the inverting amplification subunit and the sampling resistance adjustable acquisition unit. The inverting addition subunit is used to sum the first voltage and the second voltage when the first voltage is positive, and then invert the summed voltage and output it to the resistance adjustment unit. When the first voltage is negative, the first voltage is inverted and output to the resistance adjustment unit.

6. The current sampling circuit according to claim 5, characterized in that, The inverting amplification subunit includes: The first resistor, wherein the adjustable sampling resistance acquisition unit is connected to one end of the first resistor; The first operational amplifier has the other end of the first resistor connected to the inverting input terminal of the first operational amplifier, and the non-inverting input terminal of the first operational amplifier grounded. The first diode is connected to the positive terminal of the first operational amplifier, and the negative terminal of the first diode is connected to the inverting input terminal of the first operational amplifier. The second diode is connected to the negative terminal of the first operational amplifier; The second resistor has its positive terminal connected to one end of the second diode, and the other end of the second resistor is connected to the inverting input terminal of the first operational amplifier. The third resistor is connected to one end of the positive terminal of the second diode, and the other end of the third resistor is connected to the reverse adder subunit.

7. The current sampling circuit according to claim 5, characterized in that, The inverse addition subunit includes: The second operational amplifier has an inverting amplification subunit connected to the inverting input terminal of the second operational amplifier, a non-inverting input terminal of the second operational amplifier grounded, and an output terminal of the second operational amplifier connected to the resistance adjustment unit. The fourth resistor has one end connected to the sampling resistance adjustable acquisition unit and the other end connected to the inverting input terminal of the second operational amplifier. The fifth resistor has one end connected to the inverting input terminal of the second operational amplifier and the other end connected to the output terminal of the second operational amplifier.

8. The current sampling circuit according to claim 7, characterized in that, Also includes: A high-voltage sampling unit is connected to the second operational amplifier. The high-voltage sampling unit is used to acquire a third voltage and output it to the inverting input terminal of the second operational amplifier, thereby using the third voltage to correct the first voltage. The third voltage is the output voltage of the secondary side of the transformer assembly.

9. The current sampling circuit according to claim 8, characterized in that, Also includes: A transistor, wherein the collector of the transistor is connected to a low-voltage power supply, and the emitter of the transistor is connected to the primary side of the transformer assembly; A first error amplifier has a non-inverting input terminal for inputting a preset target voltage, an inverting input terminal connected to the high-voltage sampling unit, and an output terminal connected to the base of the transistor. The first error amplifier is used to adjust the base voltage of the transistor according to the error between the third voltage and the preset target voltage, thereby adjusting the input voltage on the primary side of the transformer assembly, so that the output terminal on the secondary side of the transformer assembly stably outputs the preset target voltage.

10. A high-voltage power supply, characterized in that, Includes the current sampling circuit as described in any one of claims 1 to 9.

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