CN112557979A - Nuclear magnetic resonance imaging device - Google Patents
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- CN112557979A CN112557979A CN202011416086.8A CN202011416086A CN112557979A CN 112557979 A CN112557979 A CN 112557979A CN 202011416086 A CN202011416086 A CN 202011416086A CN 112557979 A CN112557979 A CN 112557979A
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- 238000013421 nuclear magnetic resonance imaging Methods 0.000 title claims abstract description 7
- 238000003384 imaging method Methods 0.000 claims abstract description 39
- 238000001914 filtration Methods 0.000 claims abstract description 32
- 230000003321 amplification Effects 0.000 claims abstract description 25
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 25
- 101001080825 Homo sapiens PH and SEC7 domain-containing protein 1 Proteins 0.000 claims abstract description 18
- 102100027472 PH and SEC7 domain-containing protein 1 Human genes 0.000 claims abstract description 18
- 101001080808 Homo sapiens PH and SEC7 domain-containing protein 2 Proteins 0.000 claims abstract description 15
- 102100027455 PH and SEC7 domain-containing protein 2 Human genes 0.000 claims abstract description 15
- 238000001514 detection method Methods 0.000 claims abstract description 8
- 238000005481 NMR spectroscopy Methods 0.000 claims abstract description 7
- 239000003990 capacitor Substances 0.000 claims description 48
- 230000000087 stabilizing effect Effects 0.000 claims description 8
- 238000002595 magnetic resonance imaging Methods 0.000 claims description 5
- 230000010363 phase shift Effects 0.000 description 8
- 238000000034 method Methods 0.000 description 6
- 230000002238 attenuated effect Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
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- 230000003068 static effect Effects 0.000 description 1
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- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
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Abstract
The invention relates to a nuclear magnetic resonance imaging device, wherein an imaging signal receiving circuit adopts a preamplifier to receive a signal received by a nuclear magnetic resonance receiver, the signal and a reference signal phase-shifted by an adjustable phase-shifting circuit enter a multiplier PSD1 to be multiplied, the signal is amplified by a low-pass filter and differential amplification circuit and is output to an analog-digital converter after active noise removal, the precision of the received signal is improved, a noise signal receiving circuit adopts a trap amplifier to receive a noise signal, a peak detection circuit detects the output of a noise amplitude value, a harmonic frequency identification circuit multiplies the noise signal amplified by the trap amplifier and the reference signal phase-shifted by a multiplier PSD2, when the frequency is the same, the high level enters an AND gate, the detected imaging signal and the low-pass filtered imaging signal are compared, when the frequency is the same, the high level reaches the AND gate, and when the AND gate outputs the high level, +1.5V is fed back, and filtering noise frequency components, and feeding back the noise frequency components to the differential amplifying circuit through a noise amplitude value at a low level to remove the noise amplitude component.
Description
Technical Field
The invention relates to the technical field of nuclear magnetic resonance, in particular to a nuclear magnetic resonance imaging device.
Background
Magnetic Resonance Imaging (MRI) examination has become a common imaging examination method, in which a transmitter applies a radio-frequency pulse with a certain specific frequency to a human body in a static magnetic field, so that hydrogen protons in the human body are excited to generate a magnetic resonance phenomenon; after stopping the pulse, the proton generates an MR signal in the relaxation process; the MR image is generated on a computer screen through the processes of receiving MR RF (Radio Frequency) signals by a receiver, spatial encoding, image reconstruction, and the like.
The receiver can be interfered by various noises in the receiving and transmission of signals, the precision of signal receiving directly affects the image quality of nuclear magnetic resonance imaging, and a filtering method (such as mean filtering, median filtering, wiener filtering, anti-aliasing filtering and the like) is usually adopted to filter and de-noise imaging signals.
Disclosure of Invention
In view of the above situation, an object of the present invention is to provide a magnetic resonance imaging apparatus, which effectively solves the problem of insufficient accuracy of received signals due to noise suppression by using a filtering method in the prior art.
The technical scheme for solving the problem is that the device comprises an imaging signal receiving circuit, a harmonic frequency identification circuit and a noise signal receiving circuit, and is characterized in that the imaging signal receiving circuit adopts a preamplifier to receive signals received by a nuclear magnetic resonance receiver, the signals enter a multiplier PSD1 to be multiplied by reference signals subjected to phase shifting by an adjustable phase shifting circuit, the reference signals are output after low-pass filtering, phase-locked amplification receiving is realized, and then a differential amplification circuit amplifies the signals and outputs the amplified signals to an analog-to-digital converter;
the noise signal receiving circuit receives a noise signal by adopting a trap amplifier, then one path of the noise signal enters a harmonic frequency identification circuit, and the other path of the noise signal enters the harmonic frequency identification circuit after an amplitude value is detected by a peak detection circuit;
the harmonic frequency identification circuit multiplies a noise signal subjected to trap amplification by a reference signal capable of phase shifting through a multiplier PSD2 to realize phase-locked amplification and reception, when the frequency of the reference signal is the same as that of the noise signal, the output direct current voltage value is higher than the voltage stabilizing value of a voltage stabilizing tube Z2, the high level enters a pin B of an AND gate U2, the detected imaging signal and the imaging signal subjected to low-pass filtering are compared through a comparator, when the frequency of the reference signal is the same as that of the imaging signal, the high level is output and enters a pin A of the AND gate U2, logic operation is carried out on the AND gate U2, when the high level is high, a triode Q4 is conducted, and +1.5V is fed back to the adjustable phase shifting circuit and the low-pass filtering circuit to realize filtering of noise frequency components by adjusting the working frequency of phase and low-pass filtering, when the low level is low, the triode Q3 is conducted, and the, the noise amplitude component is removed.
The invention has the beneficial effects that: the pre-amplifier is adopted to receive signals received by the nuclear magnetic resonance receiver, the signals and reference signals phase-shifted by the adjustable phase-shifting circuit enter a multiplier PSD1 for multiplication, and low-pass filtering is carried out by a low-pass filter with adjustable frequency, phase-locked amplification receiving is realized, useful signals containing noise signals are detected, the problem of signal loss caused by filtering with fixed frequency is avoided, the working frequency of phase adjustment and low-pass filtering is controlled by a harmonic frequency identification circuit, then the signals are amplified by a differential amplification circuit, and the signals are output to an analog-to-digital converter after active noise removal is controlled by the harmonic frequency identification circuit, so that the precision of the received signals is improved;
the harmonic frequency identification circuit multiplies the noise signal after notch amplification by a reference signal with adjustable phase shift through a multiplier PSD2 to realize phase-locked amplification and reception of the noise signal containing the frequency component of the reference signal, when the frequency of the reference signal is the same as that of the noise signal, the high level enters a pin B of an AND gate U2, the received imaging signal detected by diodes D1 and D2 and the low-pass filtered imaging signal detected by diodes D3 and D4 are sent to a comparator for comparison, namely the reference signal outputs the high level when the frequency is the same as that of the imaging signal, the high level enters a pin A of an AND gate U2, the AND gate U2 carries out logic operation, when the high level is high, a triode Q4 is conducted, and +1.5V is fed back to the adjustable phase shift circuit and the low-pass filtering to realize the adjustment of the working frequency of phase and the low-pass filtering to filter the interference of the noise frequency component, when the low level is low level, a triode Q3 is conducted, and, and removing the noise amplitude component to realize active denoising.
Drawings
Fig. 1 is a schematic circuit diagram of the present invention.
Detailed Description
The foregoing and other technical and scientific aspects, features and utilities of the present invention will be apparent from the following detailed description of the embodiments, which is to be read in connection with the accompanying drawings of fig. 1. The structural contents mentioned in the following embodiments are all referred to the attached drawings of the specification.
Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.
In the first embodiment, a nuclear magnetic resonance imaging device comprises an imaging signal receiving circuit, a harmonic frequency identification circuit and a noise signal receiving circuit, wherein the imaging signal receiving circuit adopts a preamplifier with low noise, high gain and wide bandwidth to receive a signal received by a nuclear magnetic resonance receiver, the signal enters a pin 1 of a multiplier PSD1, a pin 2 of a multiplier PSD1 is connected with a reference signal which is phase-shifted by an adjustable phase-shifting circuit, the multiplier PSD1 multiplies two input signals, and outputs the signals after low-pass filtering by a low-pass filter with adjustable frequency to realize phase-locked amplification receiving, useful signals containing noise signals are detected, the problem of signal loss caused by filtering of fixed frequency is avoided, the useful signals are amplified by a differential amplifying circuit and are output to an analog-to-digital converter after active denoising is controlled by the harmonic frequency identification circuit, the precision of the received signals is improved, and the noise signal receiving circuit receives the noise signals by a notch amplifier, the noise signal attenuation of the frequency component of the reference signal is realized, the noise signals of other frequency components are not attenuated, one path of the noise signals enters a harmonic frequency identification circuit, the other path of the noise signals enters the harmonic frequency identification circuit after the amplitude value of the noise signals is detected by a peak detection circuit, the harmonic frequency identification circuit multiplies the noise signals subjected to notch amplification by a phase-shifting-adjustable reference signal through a multiplier PSD2 to realize the phase-locked amplification and reception of the noise signals containing the frequency component of the reference signal, the reference signal and the noise signals have the same frequency, the output direct current voltage value is higher than the voltage stabilizing value of a voltage stabilizing tube Z2, the high level enters a pin B of an AND gate U2, the received imaging signals detected by diodes D1 and D2 and the low-pass filtered imaging signals detected by diodes D3 and D4 are sent to a comparator for comparison, the amplitude of the low-pass filtered imaging signals is higher than the amplitude of the received imaging signals, and the high level is output when the frequency of, and the signal enters a pin A of an AND gate U2, an AND gate U2 carries out logic operation, a triode Q4 is conducted at high level, and +1.5V is fed back to an adjustable phase shift circuit and low-pass filtering, so that the interference of noise frequency components is filtered by adjusting the working frequency of the phase and the low-pass filtering, and the triode Q3 is conducted at low level, so that a noise signal with an amplitude value detected by a peak detection circuit is fed back to a differential amplification circuit, the noise amplitude component is removed, and active denoising is realized.
In the second embodiment, on the basis of the first embodiment, the imaging signal receiving circuit uses a low-noise, high-gain, wide-bandwidth preamplifier composed of a resistor R1-a resistor R3, an operational amplifier AR1, and a capacitor C1 to receive a signal received by the nmr receiver, and the signal enters a pin 1 of a multiplier PSD1, a pin 2 of the multiplier PSD1 is connected to a reference signal phase-shifted by an adjustable phase shift circuit, the adjustable phase shift circuit is composed of a resistor R6-a resistor R8, a MOS transistor T1, an operational amplifier AR2, and a capacitor C2, where the MOS transistor T1 is a variable resistor controlled by a gate voltage, and performs adjustable phase shift by changing the gate voltage of the MOS transistor T1, the multiplier PSD1 multiplies two input signals, and outputs the result of low-pass filtering by a low-pass filter with adjustable frequency and composed of a resistor R13, a resistor R14, a MOS transistor T2, an operational amplifier AR3, and a capacitor C3-a capacitor C5, where the MOS transistor T26 is a variable resistor 2 controlled by a gate voltage, the method comprises the steps of adjusting the working frequency of a low-pass filter by changing the grid voltage of an MOS tube T2, realizing phase-locked amplification receiving, detecting useful signals containing noise signals, avoiding the problem of signal loss caused by filtering with fixed frequency, amplifying the useful signals by a differential amplification circuit, controlling active noise removal by a harmonic frequency identification circuit, outputting the signals to an analog-to-digital converter, improving the precision of the received signals, and further performing spatial coding and image reconstruction by a post-stage circuit (the prior art is not detailed), wherein the post-stage circuit comprises a capacitor C1, a resistor R6 and a resistor R7, one end of the capacitor C1 is connected with an imaging signal, the other end of the capacitor C1 is respectively connected with one end of a grounding resistor R3 and the non-inverting input end of an operational amplifier AR1, the inverting input end of the operational amplifier AR1 is respectively connected with one end of the grounding resistor R1 and one end of the resistor R2, the output end of the operational amplifier AR1, The reference signal is connected to one end of a resistor R6 and one end of a resistor R7 of a multiplier PSD1, the reference signal is connected to the other end of a resistor R7 of the multiplier PSD1, the reference signal is connected to one end of a resistor R8 and the non-inverting input end of an operational amplifier AR2, the drain of a MOS transistor T1 is connected to the other end of the resistor R6, the source of the MOS transistor T1 is connected to one end of a grounded capacitor C2 and the inverting input end of an operational amplifier AR2, the output end of the operational amplifier AR2 is connected to the other end of a resistor R8 and the pin 2 of a multiplier 1, the pin 3 of the multiplier 86PSD 27 is connected to the source of a MOS transistor T2 through a resistor R13, the drain of a MOS transistor T2 is connected to the inverting input end of an operational amplifier AR3 and one end of a capacitor C3, the non-inverting input end of the operational amplifier AR3 is connected to one end of a grounded capacitor C3, the other end of the capacitor, The output end of the operational amplifier AR3, one end of the resistor R15, the other end of the resistor R15 are respectively connected with the other end of the resistor R16 and the inverting input end of the operational amplifier AR5, the non-inverting input end of the operational amplifier AR5 is respectively connected with one end of the resistor R17 and one end of the grounding resistor R18, the output end of the operational amplifier AR5 is respectively connected with the other end of the resistor R16 and one end of the resistor R19, and the other end of the resistor R19 is connected with the analog-to-digital converter.
In the third embodiment, on the basis of the first embodiment, the harmonic frequency identification circuit multiplies the noise signal subjected to notch amplification by the reference signal subjected to adjustable phase shift through the multiplier PSD2, so as to achieve phase-locked amplification and reception of the noise signal containing the frequency component of the reference signal, when the frequency of the reference signal is the same as that of the noise signal, the output direct-current voltage value is higher than the regulated voltage value of the zener diode Z2, the high level enters the pin B of the and gate U2, the received imaging signal detected by the diodes D1 and D2 and the low-pass filtered imaging signal detected by the diodes D3 and D4 are sent to the operational amplifier AR4, the triodes 1 and Q2, the resistor R9-resistor R12 and the capacitor C6 to be compared, the amplitude of the low-pass filtered imaging signal is higher than that of the received imaging signal, that is, when the frequency of the reference signal is the same as that of the imaging signal, the reference signal outputs the high level, the high level enters the pin a of, when the high level is high, the triode Q4 is conducted, the +1.5V is fed back to the adjustable phase shift circuit and the low-pass filter, the interference of noise frequency components is filtered by adjusting the working frequency of the phase and the low-pass filter, when the low level is low, the triode Q3 is conducted, a noise signal of an amplitude value detected by the peak detection circuit is fed back to the differential amplification circuit, the noise amplitude component is removed, active noise removal is realized, and the noise is output to the analog-to-digital converter, the noise-removing circuit comprises a multiplier PSD2, a triode Q1 and a triode Q2, a pin 1 of the multiplier PSD2 is connected with an output end of an operational amplifier AR2, a pin 2 of the multiplier PSD2 is connected with an output end of an operational amplifier AR6, a pin 3 of the multiplier PSD2 is connected with a cathode of a voltage regulator tube Z2, anodes of voltage regulator tubes Z2 are respectively connected with one end of a ground resistor R31 and a pin B of an AND gate U2, an, A non-inverting input terminal of the operational amplifier AR1, a base of the transistor Q1 is connected to ground, a collector of the transistor Q1 is respectively connected to one end of the resistor R11 and an inverting input terminal of the operational amplifier AR4, the other end of the resistor R11 is respectively connected to one end of the resistor R10 and one end of the resistor R9, the other end of the resistor R10 is connected to +5V, the other end of the resistor R90 is respectively connected to a non-inverting input terminal of the operational amplifier AR4 and a collector of the transistor Q2, an emitter of the transistor Q2 is connected to a cathode of the diode D3, an anode of the diode D3 is respectively connected to a cathode of the diode D4 and one end of the capacitor C7, the other end of the capacitor C7 is connected to an output terminal of the operational amplifier AR3, an anode of the diode D4 is connected to ground, an output terminal of the operational amplifier AR4 is respectively connected to one end of the resistor R12 and one end of the capacitor, pin a of the and gate U2 and pin Y of the and gate U2 are respectively connected to the base of the transistor Q3, one end of the ground resistor R21 and the negative electrode of the regulator tube Z1, the emitter of the transistor Q3 is connected to the negative electrode of the diode D5, the collector of the transistor Q3 is connected to the other end of the resistor R17, the anode of the regulator tube Z1 is connected to the base of the transistor Q4, the collector of the transistor Q4 is connected to +1.5V, the emitter of the transistor Q4 is connected to one end of the resistor R20, and the other end of the resistor R20 is respectively connected to one end of the ground capacitor C8, the gate of the MOS tube T1 and the gate of the MOS tube T596.
In a fourth embodiment, based on the first embodiment, the noise signal receiving circuit receives the received noise signal (which may be taken from a noise signal induced by a noise simulator, and is not described in detail herein) through the resistor R22 and then into a notch amplifier composed of the resistor R23-resistor R28, the capacitor C9-capacitor C11, and the operational amplifier AR6, so as to achieve attenuation of the noise signal of the frequency component of the reference signal, and the noise signals of other frequency components are not attenuated, and then one path of the noise signal enters the harmonic frequency identification circuit, and the other path of the noise signal enters the harmonic frequency identification circuit after the amplitude value of the noise signal is detected through a value detection circuit composed of peak diodes D5 and D6, the resistor R29, the resistor R30, and the capacitor C12, and then the harmonic frequency identification circuit includes a resistor R22, one end of the resistor R22 is connected to the noise signal, the other end of the resistor R22 is connected to one end of the resistor R23, one end of the capacitor C9, the other end of the resistor R, One end of a capacitor C11, the other end of a resistor R23 are respectively connected to one end of a resistor R24 and one end of a capacitor C10, the other end of a resistor R24, one end of a ground resistor R25 and the other end of a capacitor C11 are respectively connected to the non-inverting input terminal of an operational amplifier AR6, the other end of a resistor R26 is respectively connected to the other end of a capacitor C10, one end of a ground resistor R27, one end of a resistor R28 and the inverting input terminal of an operational amplifier AR6, the output terminal of the operational amplifier AR6 is respectively connected to the other end of a resistor R28, one end of a resistor R29 and the anode of a diode D5, the other end of a resistor R29 is respectively connected to one end of a resistor R30 and the anode of a diode D6, the cathode of the diode D6 is connected to ground, the other end of a resistor R30 is connected to a power supply +5V, and the.
When the invention is used, the imaging signal receiving circuit adopts a preamplifier with low noise, high gain and wide bandwidth to receive signals received by a nuclear magnetic resonance receiver, the signals enter a pin 1 of a multiplier PSD1, a pin 2 of the multiplier PSD1 is connected with a reference signal phase-shifted by an adjustable phase-shifting circuit, the adjustable phase-shifting circuit consists of a resistor R6-a resistor R8, a MOS tube T1, an operational amplifier AR2 and a capacitor C2, wherein the MOS tube T1 is a variable resistor controlled by grid voltage, adjustable phase shifting is carried out by changing the grid voltage of the MOS tube T1, the multiplier PSD1 multiplies two input signals, and outputs the signals after low-pass filtering by a low-pass filter with adjustable frequency consisting of the resistor R13, the resistor R14, the MOS tube T2, the operational amplifier AR3 and the capacitor C3-the capacitor C5, wherein the MOS tube T2 is a variable resistor controlled by the grid voltage, the grid voltage of the MOS tube T2 is changed, adjusting the working frequency of a low-pass filter, realizing phase-locked amplification receiving, detecting useful signals containing noise signals, avoiding the problem of signal loss caused by filtering of fixed frequency, amplifying the signals by a differential amplification circuit, controlling the noise removal by a harmonic frequency identification circuit and outputting the signals to an analog-to-digital converter, improving the precision of the received signals, enabling the noise signals received by a noise signal receiving circuit to be received by a notch amplifier, realizing the noise signal attenuation of a reference signal frequency component, enabling the noise signals of other frequency components to be not attenuated, enabling one path of the signals to enter a harmonic frequency identification circuit, enabling the other path of the signals to enter the harmonic frequency identification circuit after detecting the amplitude value of the noise signals by a peak detection circuit, enabling the harmonic frequency identification circuit to multiply the noise signals subjected to notch amplification and the reference signals capable of phase shifting through a multiplier PSD2, realizing the phase-locked amplification receiving of the noise signals containing the reference signal frequency component, when the frequency of the reference signal is the same as that of the noise signal, the output direct current voltage value is higher than the voltage stabilizing value of a voltage stabilizing tube Z2, the high level enters a pin B of an AND gate U2, the received imaging signal detected by diodes D1 and D2 and the low-pass filtered imaging signal detected by diodes D3 and D4 are sent to a comparator for comparison, the amplitude of the low-pass filtered imaging signal is higher than that of the received imaging signal, namely the high level is output when the frequency of the reference signal is the same as that of the imaging signal, the reference signal enters a pin A of an AND gate U2, the AND gate U2 carries out logic operation, when the high level is high, a triode Q4 is conducted, and +1.5V is fed back to an adjustable phase shifting circuit and low-pass filtering, so as to filter the interference of noise frequency components by adjusting the working frequency of phase and low-pass filtering, when the low level is low, the triode Q3 is conducted, the noise signal, and removing the noise amplitude component, and outputting the noise amplitude component to the analog-to-digital converter after active denoising is realized.
Claims (4)
1. A nuclear magnetic resonance imaging device comprises an imaging signal receiving circuit, a harmonic frequency identification circuit and a noise signal receiving circuit, and is characterized in that the imaging signal receiving circuit adopts a preamplifier to receive signals received by a nuclear magnetic resonance receiver, the signals enter a multiplier PSD1 to be multiplied by reference signals subjected to phase shifting by an adjustable phase shifting circuit, the signals are output after low-pass filtering, phase-locked amplification receiving is realized, and then a differential amplifying circuit amplifies the signals and outputs the amplified signals to an analog-to-digital converter;
the noise signal receiving circuit receives a noise signal by adopting a trap amplifier, then one path of the noise signal enters a harmonic frequency identification circuit, and the other path of the noise signal enters the harmonic frequency identification circuit after an amplitude value is detected by a peak detection circuit;
the harmonic frequency identification circuit multiplies a noise signal subjected to trap amplification by a reference signal capable of phase shifting through a multiplier PSD2 to realize phase-locked amplification and reception, when the frequency of the reference signal is the same as that of the noise signal, the output direct current voltage value is higher than the voltage stabilizing value of a voltage stabilizing tube Z2, the high level enters a pin B of an AND gate U2, the detected imaging signal and the imaging signal subjected to low-pass filtering are compared through a comparator, when the frequency of the reference signal is the same as that of the imaging signal, the high level is output and enters a pin A of the AND gate U2, logic operation is carried out on the AND gate U2, when the high level is high, a triode Q4 is conducted, and +1.5V is fed back to the adjustable phase shifting circuit and the low-pass filtering circuit to realize filtering of noise frequency components by adjusting the working frequency of phase and low-pass filtering, when the low level is low, the triode Q3 is conducted, and the, the noise amplitude component is removed.
2. The magnetic resonance imaging apparatus according to claim 1, wherein the imaging signal receiving circuit comprises a capacitor C1, a resistor R6 and a resistor R7, one end of the capacitor C1 is connected with the imaging signal, the other end of the capacitor C1 is connected with one end of a ground resistor R3 and the non-inverting input end of an operational amplifier AR1, the inverting input end of an operational amplifier AR1 is connected with one end of a ground resistor R1 and one end of a resistor R2, the output end of the operational amplifier AR1 is connected with the other end of a resistor R2 and the pin 1 of a multiplier PSD1, one end of a resistor R6 and one end of a resistor R7 are connected with the reference signal, the other end of a resistor R7 is connected with one end of a resistor R8 and the non-inverting input end of an operational amplifier AR2, the other end of the resistor R6 is connected with the drain AR of a MOS transistor T1, the source of the MOS transistor T1 is connected with one end of a ground capacitor C2, the output end of the operational amplifier AR2 is connected to the other end of the resistor R8 and the pin 2 of the multiplier PSD1, the pin 3 of the multiplier PSD1 is connected to the source of the MOS transistor T2 through the resistor R13, the drain of the MOS transistor T2 is connected to the inverting input end of the operational amplifier AR3 and the one end of the capacitor C4, the non-inverting input end of the operational amplifier AR3 is connected to the one end of the grounded capacitor C3, the other end of the capacitor C4 is connected to one end of the resistor R14 and one end of the capacitor C5, the other end of the resistor R14 is connected to the other end of the capacitor C5, the output end of the operational amplifier AR3 and one end of the resistor R15, the other end of the resistor R15 and the inverting input end of the operational amplifier AR 15, the non-inverting input end of the operational amplifier AR 15 is connected to one end of the resistor R15 and one end of the grounded resistor R15, the output end of the operational amplifier AR 15 is, the other end of the resistor R19 is connected with an analog-to-digital converter.
3. The magnetic resonance imaging device as claimed in claim 1, wherein the harmonic frequency identification circuit comprises a multiplier PSD2, a transistor Q1, and a transistor Q2, pin 1 of the multiplier PSD2 is connected to the output terminal of the operational amplifier AR2, pin 2 of the multiplier PSD2 is connected to the output terminal of the operational amplifier AR6, pin 3 of the multiplier PSD2 is connected to the negative terminal of a regulator tube Z2, the positive terminal of the regulator tube Z2 is connected to one end of a ground resistor R31 and pin B of an and gate U2, the emitter of the transistor Q1 is connected to the negative terminal of a diode D2, the positive terminal of the diode D2 is connected to the negative terminal of a diode D1 and the non-inverting input terminal of an operational amplifier AR1, the base of the transistor Q1 is connected to ground, the collector of the transistor Q1 is connected to one end of a resistor R11 and the inverting input terminal of an operational amplifier AR4, the other end of a resistor R11 is connected to one end of a resistor R84, the other end of the resistor R10 is connected with a power supply +5V, the other end of the resistor R90 is respectively connected with a non-inverting input end of an operational amplifier AR4 and a collector of a triode Q2, an emitter of the triode Q2 is connected with a cathode of a diode D3, an anode of a diode D3 is respectively connected with a cathode of a diode D4 and one end of a capacitor C7, the other end of the capacitor C7 is connected with an output end of an operational amplifier AR3, an anode of the diode D4 is connected with ground, an output end of the operational amplifier AR4 is respectively connected with one end of the resistor R4 and one end of the capacitor C4, the other end of the resistor R4 and the other end of the capacitor C4 are connected with a base of the triode Q4, a pin A of the AND gate U4 is respectively connected with a base of the triode Q4, one end of the ground resistor R4 and a cathode of the voltage regulator Z4, an emitter of the triode Q4 is connected with a cathode of the triode Q4, a collector of the resistor R4 is connected, the collector of the triode Q4 is connected with +1.5V of a power supply, the emitter of the triode Q4 is connected with one end of a resistor R20, and the other end of the resistor R20 is respectively connected with one end of a grounding capacitor C8, the grid of a MOS tube T1 and the grid of a MOS tube T2.
4. The magnetic resonance imaging apparatus according to claim 1, wherein the noise signal receiving circuit comprises a resistor R22, one end of the resistor R22 is connected to the noise signal, the other end of the resistor R22 is connected to one end of the resistor R23 and one end of the capacitor C9, the other end of the capacitor C9 is connected to one end of the resistor R26 and one end of the capacitor C11, the other end of the resistor R23 is connected to one end of the resistor R24 and one end of the capacitor C10, the other end of the resistor R24, one end of the ground resistor R25 and the other end of the capacitor C11 are connected to the non-inverting input terminal of the operational amplifier AR6, the other end of the resistor R26 is connected to the other end of the capacitor C10, one end of the ground resistor R27, one end of the resistor R28 and the inverting input terminal of the operational amplifier AR6, the output terminal of the operational amplifier AR6 is connected to the other end of the resistor R28, one end of the resistor R84, the other end of the resistor R29 is respectively connected with one end of a resistor R30 and the anode of a diode D6, the cathode of the diode D6 is connected with the ground, the other end of the resistor R30 is connected with a power supply +5V, and the cathode of the diode D5 and one end of a grounded capacitor C12 are connected with the emitter of the triode Q3.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114111984A (en) * | 2021-11-16 | 2022-03-01 | 郑州业伟实业有限公司 | Dynamic weighing device for loader |
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2020
- 2020-12-07 CN CN202011416086.8A patent/CN112557979A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114111984A (en) * | 2021-11-16 | 2022-03-01 | 郑州业伟实业有限公司 | Dynamic weighing device for loader |
| CN114111984B (en) * | 2021-11-16 | 2023-09-26 | 郑州业伟实业有限公司 | Dynamic weighing device for loader |
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Application publication date: 20210326 |