Sensing transmitter and voltage signal processing circuit thereof

Abstract

The invention discloses a sensing transmitter and a voltage signal processing circuit thereof, belongs to the field of transmitters, is used for realizing segmented calibration of a sensor voltage signal by using an analog circuit, and solves the problem that the voltage signal is difficult to keep higher signal precision in a strong interference environment. Considering that the precision of a voltage signal output by a sensor can be improved by adopting a segmented calibration mode and an analog circuit has relatively strong anti-interference capability, the segmented identification circuit disclosed by the invention can transmit the voltage signal to a segmented calibration circuit corresponding to a voltage value interval to which the voltage signal belongs; the segmented calibration circuit can multiply a received voltage signal by a preset slope and then add a preset intercept, and the signal conditioning circuit is used for conditioning and then outputting the voltage signal, so that segmented calibration of the voltage signal is realized, and each part of circuit is an analog circuit and has strong anti-interference capability; the high signal precision of the voltage signal can be maintained in a strong interference environment, and the application scene of the sensing transmitter is broadened.

Description

Technical Field

[0001] This invention relates to the field of transmitters, and in particular to a sensing transmitter and its voltage signal processing circuit. Background Technology

[0002] Sensor transmitters include sensors and voltage signal processing circuits. The voltage signal processing circuit can process the voltage signal output by the sensor so that the voltage signal can be transmitted accurately and stably. However, there is a lack of mature voltage signal processing circuits in related technologies, which makes it difficult for the voltage signal to maintain high signal accuracy in strong interference environments (especially strong radiation environments such as nuclear power fields), thus limiting the application scenarios of sensor transmitters.

[0003] Therefore, how to provide a solution to the above-mentioned technical problems is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a sensor transmitter and its voltage signal processing circuit. The segmented identification circuit can transmit the voltage signal to the segmented calibration circuit corresponding to the voltage value range to which the voltage signal belongs. The segmented calibration circuit can multiply the received voltage signal by a preset slope and add a preset intercept, and then output it after conditioning by the signal conditioning circuit. This achieves segmented calibration of the voltage signal. Moreover, all parts of the circuit are analog circuits, which have strong anti-interference capabilities, enabling the voltage signal to maintain high signal accuracy in strong interference environments, thus broadening the application scenarios of the sensor transmitter.

[0005] To solve the above-mentioned technical problems, the present invention provides a voltage signal processing circuit applied to a sensor transmitter, comprising:

[0006] The signal acquisition circuit is used to acquire the voltage signal output by the sensor.

[0007] The segmented identification circuit is used to transmit the voltage signal to the segmented calibration circuit corresponding to the voltage value range to which the voltage signal belongs;

[0008] Multiple segmented calibration circuits, each corresponding to a preset voltage value range, are used to multiply the received voltage signal by a preset slope and add a preset intercept to calibrate the voltage signal. The preset parameters of each segmented calibration circuit are different, including a preset slope and a preset intercept.

[0009] The signal conditioning circuit is used to condition the voltage signal output by the segmented calibration circuit in order to enable signal transmission.

[0010] Among them, the signal acquisition circuit, segment recognition circuit, segment calibration circuit, and signal conditioning circuit are all analog circuits.

[0011] On the other hand, the segmentation identification circuit includes:

[0012] The voltage threshold comparison unit, whose input terminal is connected to the output terminal of the signal acquisition circuit, is used to compare the voltage signal output by the signal acquisition circuit with multiple preset threshold voltages and output the original level signal reflecting the voltage value range to which the voltage signal belongs.

[0013] The logic signal conversion unit, whose input terminal is connected to the output terminal of the voltage threshold comparison unit, is used to perform logic conversion on the original level signal to generate a gating control signal.

[0014] The input terminals of multiple signal channels are all connected to the output terminals of the signal acquisition circuit, and the output terminals of multiple signal channels are connected one-to-one to the input terminals of the segmented calibration circuit. The channel selection unit, whose control terminal is connected to the output terminal of the logic signal conversion unit, is used to open the signal channel corresponding to the voltage value range to which the voltage signal belongs under the control of the selection control signal.

[0015] On the other hand, the voltage threshold comparison unit includes:

[0016] The non-inverting or inverting input terminal is connected to a preset threshold voltage, and the other input terminal is connected to multiple comparators at the output terminal of the signal acquisition circuit to output the original level signal;

[0017] Threshold voltage generation circuit, used to generate multiple preset threshold voltages;

[0018] The threshold voltage generation circuit includes a voltage divider circuit, the number of threshold voltages is the same as the number of comparators, and the threshold voltage is set according to the boundary value of a preset voltage value range.

[0019] On the other hand, the logic signal conversion unit includes:

[0020] The input terminal is connected to the output terminal of the voltage threshold comparison unit, which is used to perform logical combination operations on the original level signal to generate a gating control signal that conforms to the control rules of the channel gating unit.

[0021] On the other hand, the segmented calibration circuit includes a slope adjustment sub-circuit and an intercept adjustment sub-circuit:

[0022] The slope adjustment sub-circuit connected to the input terminal of the segment recognition circuit multiplies the received voltage signal by the corresponding preset slope by adjusting the resistance ratio of the resistor network.

[0023] The intercept adjustment sub-circuit includes:

[0024] A reference voltage source is used to output a reference voltage, which can be adjusted by a resistor or potentiometer to set the preset intercept.

[0025] The input terminal is connected to the reference voltage source and the output terminal of the slope adjustment sub-circuit, respectively. The output terminal is connected to the signal conditioning circuit via an adder circuit, which is used to superimpose the output signal of the slope adjustment sub-circuit with the reference voltage.

[0026] On the other hand, the slope adjustment sub-circuit includes:

[0027] An operational amplifier connected to the segmented identification circuit and the adjustable resistor network is used to multiply the received voltage signal by a corresponding preset slope.

[0028] An adjustable resistor network, including at least one potentiometer or precision adjustable resistor, is used to adjust the preset slope by changing the resistance ratio.

[0029] On the other hand, the voltage signal processing circuit also includes:

[0030] The temperature compensation circuit is used to generate a temperature compensation voltage signal based on the deviation of the actual temperature from the standard temperature, and couples the temperature compensation voltage signal to the output of each segment calibration circuit.

[0031] On the other hand, the temperature compensation circuit includes:

[0032] The temperature acquisition and processing unit is used to acquire the actual temperature through a temperature sensor and convert it into a corresponding temperature electrical signal.

[0033] The temperature compensation numerical calculation unit connected to the temperature acquisition and processing unit is used to compare the temperature electrical signal with the reference electrical signal corresponding to the standard temperature and generate a compensation voltage signal that reflects the temperature deviation.

[0034] A signal coupling unit connecting the temperature compensation numerical calculation unit and the output terminals of each segment calibration circuit is used to couple the compensation voltage signal to the output signal of the segment calibration circuit.

[0035] On the other hand, the temperature compensation numerical calculation unit includes:

[0036] The comparator circuit is used to determine whether the temperature signal corresponding to the actual temperature is higher or lower than the reference signal corresponding to the standard temperature.

[0037] Operational circuits, including subtractors and adders;

[0038] The adder is used to calculate the difference between the temperature electrical signal and the reference electrical signal;

[0039] The adder is used to convert the difference into a negative compensation voltage signal when the actual temperature is higher than the standard temperature, and to convert the difference into a positive compensation voltage signal when the actual temperature is lower than the standard temperature.

[0040] To address the aforementioned technical problems, the present invention also provides a sensor transmitter, including a sensor and a voltage signal processing circuit as described above connected to the sensor.

[0041] Beneficial effects: The present invention provides a voltage signal processing circuit. Considering that (1) the segmented calibration method can improve the accuracy of the output voltage signal of the sensor, and (2) the analog circuit has strong anti-interference capability, in the present invention, the segmented identification circuit can send the voltage signal to the segmented calibration circuit corresponding to the voltage value range to which the voltage signal belongs, so that the segmented calibration circuit can multiply the received voltage signal by a preset slope and add a preset intercept, and output it after conditioning by the signal conditioning circuit, thereby realizing the segmented calibration of the voltage signal. Moreover, each part of the circuit is an analog circuit with strong anti-interference capability, so that the voltage signal can maintain high signal accuracy in a strong interference environment, thus broadening the application scenarios of the sensor transmitter.

[0042] The present invention also provides a sensor transmitter that has the same beneficial effects as the voltage signal processing circuit described above. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the relevant technologies and the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the structure of the first voltage signal processing circuit provided by the present invention;

[0045] Figure 2 This invention provides a schematic diagram of the structure of a segmentation identification circuit;

[0046] Figure 3 A schematic diagram of a segmented calibration circuit provided by the present invention;

[0047] Figure 4 This is a schematic diagram of the structure of the second voltage signal processing circuit provided by the present invention;

[0048] Figure 5 This is a schematic diagram of a temperature compensation circuit provided by the present invention. Detailed Implementation

[0049] The core of this invention is to provide a sensor transmitter and its voltage signal processing circuit. The segmented identification circuit can transmit the voltage signal to the segmented calibration circuit corresponding to the voltage value range to which the voltage signal belongs. The segmented calibration circuit can multiply the received voltage signal by a preset slope and add a preset intercept, and then output it after conditioning by the signal conditioning circuit, thereby realizing the segmented calibration of the voltage signal. Moreover, all parts of the circuit are analog circuits, which have strong anti-interference capabilities, so that the voltage signal can maintain high signal accuracy in strong interference environments, thus broadening the application scenarios of the sensor transmitter.

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a first voltage signal processing circuit provided by the present invention. This voltage signal processing circuit is applied to a sensor transmitter and includes:

[0052] Signal acquisition circuit 1 is used to acquire the voltage signal output by the sensor;

[0053] The segment identification circuit 2 is used to transmit the voltage signal to the segment calibration circuit 3 corresponding to the voltage value range to which the voltage signal belongs;

[0054] Multiple segmented calibration circuits 3, each corresponding to a preset voltage value range, are used to multiply the received voltage signal by a preset slope and add a preset intercept to calibrate the voltage signal. The preset parameters of each segmented calibration circuit 3 are different, including a preset slope and a preset intercept.

[0055] Signal conditioning circuit 4 is used to condition the voltage signal output by segment calibration circuit 3 in order to enable signal transmission;

[0056] Among them, the signal acquisition circuit 1, the segment identification circuit 2, the segment calibration circuit 3, and the signal conditioning circuit 4 are all analog circuits.

[0057] Specifically, considering the technical problems mentioned above, and taking into account that (1) segmented calibration can improve the accuracy of the sensor output voltage signal, and (2) analog circuits have strong anti-interference capabilities, this embodiment of the invention aims to design a pure analog circuit to perform segmented calibration on the voltage signal collected from the sensor of the sensor transmitter, thereby improving the accuracy of the signal transmitted by the sensor transmitter. For example, in order to enable the sensor transmitter to work stably in a nuclear radiation environment and improve the signal processing accuracy, this embodiment of the invention can use a pure analog circuit to realize the functions of voltage signal acquisition, interval identification, segmented calibration and conditioning, so as to avoid problems such as timing violations of digital circuits in a radiation environment, and at the same time solve the defects of existing similar equipment that lack segmented calibration function.

[0058] For example, voltage signal processing circuits can be applied to nuclear-grade pressure sensor transmitters (ST). Signal acquisition circuit 1 acquires the mV-level voltage signal output from the pressure sensor and filters out noise using an RC filter network. Segment identification circuit 2 divides the signal into four intervals: 0-0.5V, 0.5-2V, 2-3V, and 3-4V. Segment calibration circuits 3, corresponding to each interval, perform calibration using preset slopes of 1.2, 1.5, 1.3, and 1.4, and preset intercepts of 0.2V, 0.3V, 0.4V, and 0.5V, respectively. Signal conditioning circuit 4 amplifies the calibrated signal to 1-5V using an operational amplifier (OPAMP). All of the above circuits are composed of analog components and do not include digital circuit modules.

[0059] Specifically, for signal acquisition circuit 1, if the voltage signal processing circuit is applied to a nuclear-grade pressure sensor transmitter, including a signal acquisition module and a signal amplification module, both adopt pure analog circuits and radiation-resistant design.

[0060] Signal acquisition module:

[0061] The core components include a radiation-hardened operational amplifier (RHOP) as a signal buffer, with its non-inverting input connected to the pressure sensor output to receive the weak 0-40mV voltage signal (including noise) from the sensor; an RC filter network (RCFN) is configured, consisting of a 2kΩ precision metal film resistor and a 220nF PTFE capacitor, connected in parallel between the operational amplifier output and ground, with a cutoff frequency of approximately 358Hz, used to filter out high-frequency noise (such as signals above 1MHz generated by electromagnetic interference) and 50Hz power frequency interference in the signal; the circuit layout adopts a close-range wiring of "sensor-filter network-buffer", with a grounded copper foil shielding layer (GNDShield) covering the surface to isolate external radiation and electromagnetic interference; the components are selected in ceramic packages (CERDIP, Ceramic Dual In-line Package), which can withstand a total dose radiation ≥30kGy.

[0062] Signal amplification module:

[0063] A radiation-hardened instrumentation amplifier (RHIA) is used, with its input connected to the output of the signal acquisition module (i.e., the 0-40mV signal output by the buffer). By adjusting an external precision resistor (Rg=100Ω), the amplification factor is set to 100 times (amplification factor formula: G=1+49.4kΩ / Rg), linearly amplifying the 0-40mV signal to 0-4V to meet the signal amplitude requirements of the subsequent segmentation identification circuit 2. A 10μH ferrite bead and a 100nF decoupling capacitor are connected in series at the amplifier power supply to suppress power supply noise coupling. The circuit layout uses differential traces to reduce common-mode interference and ensure that the nonlinear error of the amplified signal is ≤0.05%FS.

[0064] The working process of signal acquisition circuit 1: The 0-40mV noisy signal output by the sensor is first filtered out by the RC filter network of the signal acquisition module, then buffered by the anti-radiation operational amplifier, and then enters the anti-radiation instrumentation amplifier of the signal amplification module. After being amplified 100 times, a stable 0-4V signal is output and sent to segment identification circuit 2.

[0065] Specifically, the signal conditioning circuit 4 can be of various types, such as a VI conversion circuit (VIC, Voltage-to-Current Conversion Circuit), which can convert the voltage value output by the segmented calibration circuit 3 into a 4-20mA current value (the current is an analog signal, which has stronger anti-interference ability) and has a good linear proportional relationship.

[0066] Specifically, for a better explanation of the embodiments of the present invention, please refer to... Figure 1 , Figure 1 This is a schematic diagram of a voltage signal processing circuit provided by the present invention. Except for the sensor, each part can be set on the circuit board. The sensor is set independently. The power supply module can supply power to each part respectively. The power supply module can supply power to the sensor in the sensor transmitter through a voltage regulation module with isolation function to avoid mutual interference between signals.

[0067] This invention provides a voltage signal processing circuit. Considering that (1) segmented calibration can improve the accuracy of the output voltage signal of the sensor, and (2) analog circuits have strong anti-interference capabilities, in this invention, the segmented identification circuit can send the voltage signal to the segmented calibration circuit corresponding to the voltage value range to which the voltage signal belongs, so that the segmented calibration circuit can multiply the received voltage signal by a preset slope and add a preset intercept, and output it after conditioning by the signal conditioning circuit, thereby realizing the segmented calibration of the voltage signal. Moreover, each part of the circuit is an analog circuit with strong anti-interference capabilities, so that the voltage signal can maintain high signal accuracy in a strong interference environment, thus broadening the application scenarios of the sensor transmitter.

[0068] Based on the above embodiments:

[0069] As an optional embodiment, the segmentation identification circuit 2 includes:

[0070] The voltage threshold comparison unit, whose input terminal is connected to the output terminal of the signal acquisition circuit 1, is used to compare the voltage signal output by the signal acquisition circuit 1 with a plurality of preset threshold voltages and output the original level signal reflecting the voltage value range to which the voltage signal belongs.

[0071] The logic signal conversion unit, whose input terminal is connected to the output terminal of the voltage threshold comparison unit, is used to perform logic conversion on the original level signal and generate a gating control signal.

[0072] The input terminals of multiple signal channels are all connected to the output terminal of signal acquisition circuit 1, and the output terminals of multiple signal channels are connected one-to-one to the input terminal of segment calibration circuit 3. The channel selection unit, which is connected to the output terminal of logic signal conversion unit, is used to open the signal channel corresponding to the voltage value range of the voltage signal under the control of the selection control signal.

[0073] Specifically, in order to achieve automatic identification of the voltage value range to which the voltage signal belongs, this embodiment of the invention can replace the range judgment method that relies on digital circuits with a combination of pure analog circuits for voltage comparison, logic conversion and channel selection, so as to ensure reliable range division in the nuclear radiation environment and provide a basis for subsequent segmented calibration. The above-mentioned segmented identification circuit 2 is set in this embodiment of the invention.

[0074] Specifically, for example, in the segmented identification circuit 2, the voltage threshold comparison unit uses four comparators to compare the 1.1V signal output from the signal acquisition circuit 1 with the 0.5V, 2V, 3V, and 4V thresholds, and outputs the original level signal of "1,0,0,0". The logic signal conversion unit consists of three NAND gates, which convert the original level signal into a gating control signal of "1,0,0". The channel gating unit uses a multiplexed analog switch (MAS), which opens the corresponding channel under the action of the gating control signal and sends the 1.1V signal to the segmented calibration circuit 3 corresponding to the 0.5-2V range.

[0075] Of course, in addition to the specific form described above, the segmentation identification circuit 2 can also take other forms, and the embodiments of the present invention are not limited here.

[0076] As an optional embodiment, the voltage threshold comparison unit includes:

[0077] The non-inverting or inverting input terminal is connected to a preset threshold voltage, and the other input terminal is connected to multiple comparators at the output terminal of the signal acquisition circuit 1 to output the original level signal;

[0078] Threshold voltage generation circuit, used to generate multiple preset threshold voltages;

[0079] The threshold voltage generation circuit includes a voltage divider circuit. The number of threshold voltages is the same as the number of comparators. The threshold voltage is set according to the boundary value of a preset voltage value range.

[0080] Specifically, in order to accurately determine the range to which the voltage signal belongs, this embodiment of the invention uses a comparator to compare the signal with a preset threshold voltage. The threshold voltage is set according to the range boundary value. A pure analog comparator is used to achieve direct output of the signal level, avoiding the radiation sensitivity problem caused by digital circuit processing.

[0081] Specifically, in order to provide a stable threshold voltage for interval identification, multiple precise thresholds can be generated by a voltage divider circuit in this embodiment of the invention. A pure analog resistor voltage divider method is used to ensure that the threshold voltage can be flexibly set according to the interval requirements and is stably output in a radiation environment.

[0082] For example, the threshold voltage generation circuit is a voltage divider circuit, consisting of a 10V DC power supply and precision resistors of 1kΩ, 3kΩ, 5kΩ, and 7kΩ connected in series. The voltage divider generates threshold voltages of 0.5V, 2V, 3V, and 4V respectively, which are then output to the inverting input of each comparator.

[0083] Of course, in addition to the specific forms described above, the voltage threshold comparison unit can also take other forms, and the embodiments of the present invention are not limited here.

[0084] As an optional embodiment, the logic signal conversion unit includes:

[0085] The input terminal and the output terminal of the voltage threshold comparison unit are connected to multiple logic gate circuits to perform logical combination operations on the original level signal to generate a gating control signal that conforms to the control rules of the channel gating unit.

[0086] Specifically, considering that the original level signal output by the voltage threshold comparison unit needs to be converted into a signal that conforms to the control logic of the channel selection unit, this embodiment of the invention achieves signal conversion in the pure analog domain through the combination operation of logic gate circuits, ensuring the accuracy of channel selection and stability under radiation environment.

[0087] Specifically, for a better explanation of the embodiments of the present invention, please refer to... Figure 2 , Figure 2 This is a schematic diagram of a segmented identification circuit 2 provided by the present invention. The segmented identification circuit 2 in the figure consists of a voltage threshold comparison unit, a logic signal conversion unit, a channel selection unit, and supporting components, as indicated below:

[0088] (1) Circuit composition and identification analysis:

[0089] Core functional units:

[0090] Voltage threshold comparison unit: Composed of operational amplifiers (comparators) U3A, U3B, U3C, and U3D (operating in open-loop comparison mode);

[0091] Logic signal conversion unit: composed of logic gates U1A, U1B, U1C, U1D, and U2D;

[0092] Channel selection unit: Composed of multiple analog switches S1.

[0093] Passive components and power supplies: Resistors: R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R16 (including threshold voltage dividers, signal connections, pull-up / pull-down resistors);

[0094] Power supply: VSS 5V (low voltage power supply), VCC 5.5V (op-amp / logic gate power supply), ±5.5V VEE (multi-channel switching power supply).

[0095] (2) Signal flow and working mechanism:

[0096] Signal input:

[0097] The output signal of signal acquisition circuit 1 is connected to R16 and sent to the non-inverting input terminal (+) of U3A, U3B, U3C and U3D.

[0098] Threshold voltage generation:

[0099] The VSS5V provides different threshold voltages (such as interval boundary values) to the inverting input terminal (-) of U3A-U3D through a voltage divider network composed of R5, R1, R2, R3, R4, R10, R11, and R12. Among them, the independent voltage divider resistors R11 and R12 can generate smaller and more precise voltage thresholds to meet the requirements of precise voltage thresholds.

[0100] Threshold comparison operation:

[0101] U3A-U3D compares the "input signal (non-inverting input)" with the "threshold voltage (inverting input)" and outputs the original level signal (high / low level); R6-R9 are pull-up resistors for the open-loop output of the op-amp, ensuring level compatibility with subsequent logic gates.

[0102] Logic signal conversion:

[0103] The original level signal is input to the NOR gate logic network composed of U1A-U1D and U2D, and converted into the control signal of S1 (A0, A1, A2, EOS, etc. pin levels).

[0104] Channel selection output:

[0105] After receiving the control signal, S1 selects the corresponding input channel (IN1-IN8), and the signal is output to the subsequent segment calibration circuit 3 via R13, completing the signal routing from "interval identification to channel selection".

[0106] (3) Key design features:

[0107] Radiation resistance: The operational amplifiers (U3A-U3D) are radiation-resistant models, resistant to nuclear radiation environments, with an open-loop gain ≥100dB, ensuring threshold comparison accuracy;

[0108] Analog domain implementation: The entire function is completed through pure analog circuits (operational amplifier comparator, logic gate operation, analog switch gating), avoiding the timing risks of digital circuits in the radiation environment;

[0109] This circuit, through hierarchical analog circuit design, realizes the full-process function of "voltage range identification - logic conversion - channel selection", providing a reliable signal path for subsequent segmented calibration and meeting the stable operation requirements under nuclear radiation environment.

[0110] Of course, in addition to the specific forms described above, the logic signal conversion unit can also take other forms, and the embodiments of the present invention are not limited here.

[0111] As an optional embodiment, the segmented calibration circuit 3 includes a slope adjustment sub-circuit and an intercept adjustment sub-circuit:

[0112] The slope adjustment sub-circuit connected to the input terminal of the segment recognition circuit 2 multiplies the received voltage signal by the corresponding preset slope by adjusting the resistance ratio of the resistor network.

[0113] The intercept adjustment sub-circuit includes:

[0114] A reference voltage source is used to output a reference voltage, which can be adjusted by a resistor or potentiometer to set a preset intercept.

[0115] The input terminals are connected to the reference voltage source and the output terminal of the slope adjustment sub-circuit, respectively. The output terminal is connected to the addition circuit of the signal conditioning circuit 4, which is used to superimpose the output signal of the slope adjustment sub-circuit with the reference voltage.

[0116] Specifically, considering that the actual voltage signal exhibits nonlinear characteristics in different ranges, accurate calibration can be achieved by segmenting the slope and intercept. Therefore, in this embodiment of the invention, a pure analog method is adopted to adjust the slope using a resistor network and adjust the intercept by superimposing a reference voltage, thus avoiding the unreliability of digital calibration in a radiation environment.

[0117] Of course, in addition to the specific form described above, the segmented calibration circuit 3 can also take other forms, and the embodiments of the present invention are not limited here.

[0118] As an optional embodiment, the slope adjustment sub-circuit includes:

[0119] An operational amplifier connected to the segmentation identification circuit 2 and the adjustable resistor network is used to multiply the received voltage signal by the corresponding preset slope.

[0120] An adjustable resistor network, including at least one potentiometer or precision adjustable resistor, is used to adjust a preset slope by changing the resistance ratio.

[0121] Specifically, in order to accurately adjust the preset slope of segmented calibration, this embodiment of the invention can use a combination of operational amplifier and adjustable resistor network to achieve continuous adjustment of the resistance ratio within the analog domain, ensuring that the slope parameters of different intervals can be flexibly set and improving calibration accuracy.

[0122] Specifically, for a better explanation of the embodiments of the present invention, please refer to... Figure 3 , Figure 3 This is a schematic diagram of a segmented calibration circuit 3 provided by the present invention. The segmented calibration circuit 3 consists of a slope adjustment sub-circuit, an intercept adjustment sub-circuit, and supporting components, as indicated below:

[0123] (1) Circuit composition and identification analysis:

[0124] Core functional units:

[0125] Slope adjustment sub-circuit: composed of operational amplifier U30;

[0126] Intercept adjustment sub-circuit: It consists of voltage follower U32 and voltage divider circuit (corresponding to reference voltage source) and operational amplifier U31 (corresponding to addition operation circuit).

[0127] Passive components and power supplies:

[0128] Resistors: R83, R84, R85, R86, R87, R88, R89, R90, R91 (including feedback adjustment, voltage divider, and current limiting resistors);

[0129] Capacitors: C57, C58, C59, C60, C61 (power supply decoupling and signal filtering capacitors);

[0130] Power supply: 5V (op-amp power supply), VEF2.5 (2.5V reference voltage, used for intercept adjustment).

[0131] Signal interface:

[0132] Input: VIN (output voltage of segment identification circuit 2);

[0133] Output: Pin 1 of U31 (output of segment calibration circuit 3, which is sent to subsequent signal conditioning circuit 4).

[0134] (2) Signal flow and working mechanism:

[0135] Slope adjustment sub-circuit (U30 module):

[0136] Signal input: Vin is connected to the non-inverting input (pin 3) of U30;

[0137] Feedback network: The inverting input (pin 4) of U30 forms an adjustable feedback network through R84, R85, and R83.

[0138] R85 is a precision potentiometer. Adjusting its resistance value can change the feedback coefficient, thereby adjusting the amplification factor of U30 (i.e., the "preset slope", such as adjusting the slope from 1.2 to 1.5 by adjusting the resistance value ratio).

[0139] R83 and R84 are fixed resistors, which work together with R85 to form a closed-loop feedback to ensure amplification linearity.

[0140] Power supply filtering: C57 is connected in parallel to the 5V power supply terminal of U30 to filter out power supply noise and improve the stability of slope adjustment.

[0141] Reference voltage source:

[0142] Reference voltage: VEF2.5 provides a stable 2.5V reference, which is connected to the IN+ terminal (pin 3) of U32.

[0143] Voltage divider adjustment: R90 and R91 form an adjustable voltage divider circuit (R91 is a potentiometer) to divide the 2.5V reference voltage and output a cutoff compensation voltage (connected to the non-inverting input of U31, corresponding to the "preset cutoff", such as a cutoff adjustment of 0.2~0.5V).

[0144] Filtering and voltage regulation: C60 is connected in parallel to the output of the voltage divider circuit to filter out voltage divider noise; C59 is the power supply decoupling capacitor of U32 to ensure the accuracy of the reference buffer.

[0145] Addition circuit (U31 module):

[0146] Signal input:

[0147] The output of U30 (the signal after slope adjustment) is connected to the non-inverting input (pin 3) of U31 via R88.

[0148] The cutoff compensation voltage is connected to the non-inverting input (pin 3) of U31 via R86.

[0149] Operational feedback: R87 and R89 form a feedback network to construct an addition operation model (by setting the superposition weight of slope and intercept through resistor ratio) to achieve the linear superposition of "slope adjustment signal + intercept compensation voltage".

[0150] Power supply filtering: C58 is connected in parallel to the 5V power supply terminal of U31 to suppress the interference of power fluctuations on the output.

[0151] (3) Key design features

[0152] Pure analog calibration: The entire process uses operational amplifiers, resistor networks, and reference sources to achieve "slope adjustment-intercept compensation-signal superposition", which fits the "pure analog circuit" design and avoids the radiation sensitivity of digital calibration;

[0153] Parameter adjustability: Continuous parameter adjustment is achieved through R85 (slope) and R91 (intercept) to adapt to nonlinear compensation requirements in different ranges (such as slope 1.2 and intercept 0.2V in the 0-0.5V range, slope 1.3 and intercept 0.4V in the 2-3V range, etc.).

[0154] Anti-interference design: Decoupling capacitors (C57, C58, C59) are configured on the power supply side, and filter capacitors (C60, C61) are used in the signal path to suppress noise coupling in the radiation environment and ensure calibration accuracy.

[0155] This circuit achieves precise calibration of "slope linear amplification + intercept voltage compensation" through hierarchical analog circuit design, providing stable and adjustable segmented compensation capability for voltage signal processing under nuclear radiation environment.

[0156] As an optional embodiment, the voltage signal processing circuit further includes:

[0157] Temperature compensation circuit 5 is used to generate a temperature compensation voltage signal based on the deviation of the actual temperature from the standard temperature, and couple the temperature compensation voltage signal to the output of each segment calibration circuit 3.

[0158] Specifically, for a better explanation of the embodiments of the present invention, please refer to... Figure 4 , Figure 4 The diagram shows the structure of the second voltage signal processing circuit provided by the present invention. A temperature compensation circuit 5 is introduced in the diagram. Considering that temperature changes will cause the sensor output signal to drift, the present invention can generate a temperature compensation voltage through an analog circuit and couple it to the calibration signal (the output of each segment calibration circuit 3) to eliminate temperature error and solve the problem of radiation environment incompatibility of related equipment that relies on digital circuits to achieve temperature compensation.

[0159] For example, when the actual temperature is 50℃ (standard temperature is 25℃), the temperature compensation circuit 5 generates a temperature compensation voltage signal of -0.15V; this signal is coupled to the 1.65V signal output by the segmented calibration circuit 3, and finally outputs a 1.5V compensated signal to eliminate the signal deviation caused by the temperature rise.

[0160] As an optional embodiment, the temperature compensation circuit 5 includes:

[0161] The temperature acquisition and processing unit is used to acquire the actual temperature through a temperature sensor and convert it into a corresponding temperature electrical signal.

[0162] The temperature compensation numerical calculation unit, which is connected to the temperature acquisition and processing unit, is used to compare the temperature electrical signal with the reference electrical signal corresponding to the standard temperature and generate a compensation voltage signal that reflects the temperature deviation.

[0163] The signal coupling unit, which connects the temperature compensation numerical calculation unit and the output terminals of each segment calibration circuit 3, is used to couple the compensation voltage signal to the output signal of the segment calibration circuit 3.

[0164] Specifically, for a better explanation of the embodiments of the present invention, please refer to... Figure 5 , Figure 5 This is a schematic diagram of the structure of a temperature compensation circuit 5 provided by the present invention. In order to realize a complete temperature compensation process, the embodiments of the present invention can use a pure analog circuit chain of temperature acquisition and processing unit, compensation value calculation unit and signal coupling unit to avoid digital processing from temperature signal acquisition to compensation implementation, thereby ensuring the stability of temperature compensation under nuclear radiation environment.

[0165] Specifically, for example, the temperature acquisition and processing unit acquires the ambient temperature of 50℃ through a thermistor and converts it into a 0.8V temperature electrical signal; the temperature compensation numerical calculation unit compares this signal with the 0.5V reference electrical signal corresponding to 25℃ and generates a -0.15V compensation voltage; the signal coupling unit couples the -0.15V to the output signal of the segmented calibration circuit 3 through an operational amplifier adder circuit.

[0166] As an optional embodiment, the temperature compensation numerical calculation unit includes:

[0167] The comparator circuit is used to determine whether the temperature signal corresponding to the actual temperature is higher or lower than the reference signal corresponding to the standard temperature.

[0168] Operational circuits, including subtractors and adders;

[0169] An adder is used to calculate the difference between the temperature electrical signal and the reference electrical signal;

[0170] The adder is used to convert the difference into a negative compensation voltage signal when the actual temperature is higher than the standard temperature, and to convert the difference into a positive compensation voltage signal when the actual temperature is lower than the standard temperature.

[0171] Specifically, in order to accurately determine the direction of temperature deviation and calculate the corresponding compensation value, in this embodiment of the invention, a comparator circuit can be used to determine the temperature level, and by combining the operations of a subtractor and an adder, positive and negative compensation voltage signals in the analog domain can be generated to ensure that the compensation value matches the temperature deviation.

[0172] For example, the comparator circuit of the temperature compensation numerical calculation unit compares the 0.8V temperature signal corresponding to 50℃ with the 0.5V temperature signal corresponding to 25℃, and outputs a high level to indicate that the actual temperature is higher than the standard temperature; in the arithmetic circuit, the subtractor calculates the deviation of 0.8V-0.5V=0.3V, and the adder converts 0.3V into a negative compensation voltage of -0.15V; if the actual temperature is 10℃ (corresponding to 0.3V), the adder converts 0.5V-0.3V=0.2V into a positive compensation voltage of +0.1V.

[0173] Alternatively, as an optional embodiment, the channel selection unit includes a multiplexer analog switch;

[0174] The input terminals of the multiple signal channels of the multi-channel analog switch are respectively connected to the output terminals of the signal acquisition circuit 1, and the output terminals of the multiple signal channels are respectively connected to the input terminals of the corresponding segment calibration circuit 3.

[0175] A multi-channel analog switch is used to select the corresponding signal channel based on the selection control signal received from the control terminal.

[0176] Specifically, in order to switch signal channels based on the interval identification results, this embodiment of the invention can use a multi-channel analog switch as a channel selection unit, and realize channel switching through analog control signals to ensure accurate selection of signal paths in pure analog circuits and adapt to the requirements of radiation environment.

[0177] Specifically, for example, the channel selection unit uses a multi-channel analog switch, with the input terminals of its eight signal channels all connected to the 1.1V signal output from the signal acquisition circuit 1, and the output terminals connected to four segmented calibration circuits 3 respectively; the control terminals A0, A1, and A2 are connected to the "1,0,0" level output from the logic signal conversion unit, which selects the second channel and sends the 1.1V signal to the segmented calibration circuit 3 corresponding to the 0.5-2V range.

[0178] The present invention also provides a sensing transmitter, including a sensor and a voltage signal processing circuit as described in the foregoing embodiments connected to the sensor.

[0179] For a description of the sensor transmitter provided in the embodiments of the present invention, please refer to the aforementioned embodiments of the voltage signal processing circuit; the embodiments of the present invention will not be repeated here.

[0180] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should also be noted that in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0181] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A voltage signal processing circuit, characterized in that, Applications in sensor transmitters include: The signal acquisition circuit is used to acquire the voltage signal output by the sensor. The segmented identification circuit is used to transmit the voltage signal to the segmented calibration circuit corresponding to the voltage value range to which the voltage signal belongs; Multiple segmented calibration circuits, each corresponding to a preset voltage value range, are used to multiply the received voltage signal by a preset slope and add a preset intercept to calibrate the voltage signal. The preset parameters of each segmented calibration circuit are different, including a preset slope and a preset intercept. The signal conditioning circuit is used to condition the voltage signal output by the segmented calibration circuit in order to enable signal transmission. Among them, the signal acquisition circuit, segment recognition circuit, segment calibration circuit, and signal conditioning circuit are all analog circuits.

2. The voltage signal processing circuit according to claim 1, characterized in that, The segmentation identification circuit includes: The voltage threshold comparison unit, whose input terminal is connected to the output terminal of the signal acquisition circuit, is used to compare the voltage signal output by the signal acquisition circuit with multiple preset threshold voltages and output the original level signal reflecting the voltage value range to which the voltage signal belongs. The logic signal conversion unit, whose input terminal is connected to the output terminal of the voltage threshold comparison unit, is used to perform logic conversion on the original level signal to generate a gating control signal. The input terminals of multiple signal channels are all connected to the output terminals of the signal acquisition circuit, and the output terminals of multiple signal channels are connected one-to-one to the input terminals of the segmented calibration circuit. The channel selection unit, whose control terminal is connected to the output terminal of the logic signal conversion unit, is used to open the signal channel corresponding to the voltage value range to which the voltage signal belongs under the control of the selection control signal.

3. The voltage signal processing circuit according to claim 2, characterized in that, The voltage threshold comparison unit includes: The non-inverting or inverting input terminal is connected to a preset threshold voltage, and the other input terminal is connected to multiple comparators at the output terminal of the signal acquisition circuit to output the original level signal; Threshold voltage generation circuit, used to generate multiple preset threshold voltages; The threshold voltage generation circuit includes a voltage divider circuit, the number of threshold voltages is the same as the number of comparators, and the threshold voltage is set according to the boundary value of a preset voltage value range.

4. The voltage signal processing circuit according to claim 2, characterized in that, The logic signal conversion unit includes: The input terminal is connected to the output terminal of the voltage threshold comparison unit, which is used to perform logical combination operations on the original level signal to generate a gating control signal that conforms to the control rules of the channel gating unit.

5. The voltage signal processing circuit according to claim 1, characterized in that, The segmented calibration circuit includes a slope adjustment sub-circuit and an intercept adjustment sub-circuit: The slope adjustment sub-circuit connected to the input terminal of the segment recognition circuit multiplies the received voltage signal by the corresponding preset slope by adjusting the resistance ratio of the resistor network. The intercept adjustment sub-circuit includes: A reference voltage source is used to output a reference voltage, which can be adjusted by a resistor or potentiometer to set the preset intercept. The input terminal is connected to the reference voltage source and the output terminal of the slope adjustment sub-circuit, respectively. The output terminal is connected to the signal conditioning circuit via an adder circuit, which is used to superimpose the output signal of the slope adjustment sub-circuit with the reference voltage.

6. The voltage signal processing circuit according to claim 5, characterized in that, The slope adjustment sub-circuit includes: An operational amplifier connected to the segmented identification circuit and the adjustable resistor network is used to multiply the received voltage signal by a corresponding preset slope. An adjustable resistor network, including at least one potentiometer or precision adjustable resistor, is used to adjust the preset slope by changing the resistance ratio.

7. The voltage signal processing circuit according to any one of claims 1 to 6, characterized in that, The voltage signal processing circuit further includes: The temperature compensation circuit is used to generate a temperature compensation voltage signal based on the deviation of the actual temperature from the standard temperature, and couples the temperature compensation voltage signal to the output of each segment calibration circuit.

8. The voltage signal processing circuit according to claim 7, characterized in that, The temperature compensation circuit includes: The temperature acquisition and processing unit is used to acquire the actual temperature through a temperature sensor and convert it into a corresponding temperature electrical signal. The temperature compensation numerical calculation unit connected to the temperature acquisition and processing unit is used to compare the temperature electrical signal with the reference electrical signal corresponding to the standard temperature and generate a compensation voltage signal that reflects the temperature deviation. A signal coupling unit connecting the temperature compensation numerical calculation unit and the output terminals of each segment calibration circuit is used to couple the compensation voltage signal to the output signal of the segment calibration circuit.

9. The voltage signal processing circuit according to claim 8, characterized in that, The temperature compensation numerical calculation unit includes: The comparator circuit is used to determine whether the temperature signal corresponding to the actual temperature is higher or lower than the reference signal corresponding to the standard temperature. Operational circuits, including subtractors and adders; The adder is used to calculate the difference between the temperature electrical signal and the reference electrical signal; The adder is used to convert the difference into a negative compensation voltage signal when the actual temperature is higher than the standard temperature, and to convert the difference into a positive compensation voltage signal when the actual temperature is lower than the standard temperature.

10. A sensor transmitter, characterized in that, It includes a sensor, and also includes a voltage signal processing circuit as described in any one of claims 1 to 9 connected to the sensor.

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