CN217824735U

CN217824735U - Isolated high-precision sensor voltage transmitter circuit

Info

Publication number: CN217824735U
Application number: CN202123373918.5U
Authority: CN
Inventors: 何孝起
Original assignee: Shanghai Xingsai Electronic Technology Co ltd
Current assignee: Shanghai Xingsai Electronic Technology Co ltd
Priority date: 2021-12-30
Filing date: 2021-12-30
Publication date: 2022-11-15
Anticipated expiration: 2031-12-30

Abstract

The utility model relates to a sensor voltage changer circuit field, concretely relates to isolated form high accuracy sensor voltage changer circuit, including power input module, isolation module, reference voltage module, signal conditioning module and output interface, the utility model discloses an isolated form high accuracy sensor voltage changer circuit aims at solving the problem that traditional changer anti-electromagnetic interference ability is weak, the output accuracy is low and to have carried out the optimal treatment to power input interface, makes it have prevent the function of transposition, prevent surge, wide voltage input, the utility model discloses an isolated form high accuracy sensor voltage changer circuit has following advantage: the reference voltage is subjected to multi-stage follower processing, stable reference voltage is output, and wide-range adjustability of the reference voltage is achieved; the power input module is optimized, and has the functions of preventing surge, preventing reverse connection and inputting wide voltage; the power supply is isolated from the signal processing module, so that the precision and the anti-interference capability of the transmitter are improved.

Description

Isolated high-precision sensor voltage transmitter circuit

Technical Field

The utility model relates to a sensor voltage changer circuit field, concretely relates to isolated form high accuracy sensor voltage changer circuit.

Background

The transducer is a transducer which converts the output signal of the sensor into a signal which can be identified by the controller or converts the non-electricity input by the sensor into an electric signal and amplifies the electric signal simultaneously so as to provide a signal source for remote measurement and control, the sensor and the transducer together form an automatic control monitoring signal source, different physical quantities need different sensors and corresponding transducers, common transducers comprise two-wire transducers, three-wire transducers and four-wire transducers, the two-wire transducer combines a power supply circuit and a signal circuit into one, two wires realize power supply and communication, the three-wire transducer separates the positive end of the power supply circuit from the positive end of the communication circuit, but the power supply and communication share a COM end, the four-wire transducer completely separates the power supply circuit from the signal circuit, each circuit is formed by two wires into a loop, the common output mode has two types of current type and voltage type, and the common transducer has the following defects:

1. the three-wire transmitter has weak anti-interference capability, and the noise of the current enters the circuit processing module through the ground, so that the output voltage has large noise and low output precision.

2. The three-wire transmitter does not have the characteristic of wide voltage input, and does not correspondingly protect a power input interface.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an isolated form high accuracy sensor voltage transducer circuit.

To achieve the purpose, the utility model adopts the following technical proposal:

the isolated high-precision sensor voltage transducer circuit comprises a power supply input module, an isolation module, a reference voltage module, a signal conditioning module and an output interface.

Further, the power input module comprises a diode D1, a diode T1, a diode C1, a filter capacitor C1, a DC/DC power chip U1, a precision resistor R2, a capacitor C4, a power supply connected to the anode of D1, a power supply connected to the cathode of U1, a power supply connected in parallel to T1, a power supply connected in series to C1 between the cathode of D1 and one end of C4, a ground connected to the other end of C4, a state regulation terminal connected to the output voltage of U1 and the state regulation terminal R1, a state regulation terminal connected to U1 at one end of R2, and a ground connected to the other end of R2.

Further, the isolation module comprises C3, C2, C5 and U2, wherein C3 is a filter capacitor, C2 and C5 are capacitors, U2 is a power isolation module, C3 is connected in parallel between the positive and negative electrodes of the input voltage end of U2, C2 is connected in series between the positive electrode of the output voltage end of U2 and ground, C5 is connected in series between the negative electrode of the output voltage end of U2 and ground, and the ground end of U2 is grounded.

Further, the reference voltage module comprises U4, R4, U3A, U B, R, R10, R3, VR2, U5A and U5B, wherein U4 is a high-precision reference power supply and provides a 1.2V reference voltage for the circuit, R4 is a pull-up resistor, U3A, U B forms a two-stage follower, U3A outputs the +1.2V reference voltage in an inverted manner, U3B outputs the-1.2V voltage in an inverted manner to one bit, R9 and R10 are follower resistors of a comparator, the comparator is controlled to output the voltage to one bit, R3 is the pull-up resistor, VR2 is a sliding rheostat, a stable reference voltage is output to the inverted input end of U5B according to the processing of the reference voltage by the U5A follower, and C7 and C11 are ground-to-ground isolation capacitors.

Further, the signal conditioning module comprises R5, R7, U5B, VR, VR3, C12, C13, and C14, wherein R5 is an input resistor, R7 is a feedback resistor, U5B is an operational amplifier, VR1 is a sliding variable resistance signal input by VR3, the resistance of VR1 is adjusted to adjust the amplifier multiple of the operational amplifier, and C12, C13, and C14 are ground isolation capacitors.

The utility model has the advantages that:

the utility model discloses an isolated form high accuracy sensor voltage transducer circuit aims at solving the problem that traditional changer anti-electromagnetic interference ability is weak, the output precision is low and to carry out optimization processing to power input interface, makes it have prevent the function of anti-transposition, anti-surge, wide voltage input, the utility model discloses an isolated form high accuracy sensor voltage transducer circuit has following advantage:

1. and the reference voltage is subjected to multi-stage follower processing, stable reference voltage is output, and wide-range adjustability of the reference voltage is realized.

2. The power input module is optimized, and the power input module has the functions of preventing surge, preventing reverse connection and inputting wide voltage.

3. The power supply is isolated from the signal processing module, so that the precision and the anti-interference capability of the transmitter are improved.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below.

Fig. 1 is an overall block diagram of the present invention;

fig. 2 is a circuit diagram of the power supply voltage stabilization module of the present invention;

fig. 3 is a circuit diagram of the isolation module of the present invention;

fig. 4 is a circuit diagram of the reference voltage module of the present invention;

fig. 5 is a circuit diagram of the signal conditioning module of the present invention;

Detailed Description

The technical solution of the present invention is further explained by the following embodiments with reference to the drawings.

Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; for a better understanding of the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product.

Referring to fig. 1 to 5, an isolated high-precision sensor voltage transmitter circuit includes a power input module, an isolation module, a reference voltage module, a signal conditioning module, and an output interface.

The power input module comprises a diode D1, a T1, a C1, a U1, a R2 and a C4, wherein the D1 is a TVS tube, the T1 is a filter capacitor, the U1 is a DC/DC power chip, the R1 and the R2 are precision resistors, the C4 is a capacitor, the anode of the D1 is connected with a power supply, the cathode is connected with the input voltage end of the U1, the T1 is connected between two power supply stages in parallel, the C1 is connected between the cathode of the D1 and one end of the C4 in series, the other end of the C4 is grounded, the R1 is connected between the output voltage end of the U1 and the state adjusting end in series, one end of the R2 is connected with the state adjusting end of the U1, and the other end of the R2 is grounded. As shown in fig. 2, D1 is an anti-reverse diode, T1 is a TVS tube, C1 is a power filter capacitor, U1 is a DCDC power chip, which has a function of wide voltage input, R1 and R2 are precision resistors, and C4 is an isolation capacitor to ground.

The isolation module comprises C3, C2, C5 and U2, wherein C3 is a filter capacitor, C2 and C5 are capacitors, U2 is a power isolation module, C3 is connected in parallel between the positive electrode and the negative electrode of the input voltage end of U2, C2 is connected in series between the positive electrode of the output voltage end of U2 and the ground, C5 is connected in series between the negative electrode of the output voltage end of U2 and the ground, and the grounding end of U2 is grounded. As shown in fig. 3, the isolation module completely isolates the power supply from the signal, C3 is a filter capacitor, C2 and C5 are isolation capacitors to ground, and U2 is the power supply isolation module, which can realize isolation of the power supply from the ground and stably output 15V voltage.

The reference voltage module comprises U4, R4, U3A, U3B, R, R10, R3, VR2, U5A and U5B, wherein U4 is a high-precision reference power supply and provides a 1.2V reference voltage for a circuit, R4 is a pull-up resistor, U3A, U B forms a two-stage follower, U3A outputs the input +1.2V reference voltage in an inverted mode to form a-1.2V voltage, U3B outputs the-1.2V voltage in an inverted mode to form a +1.2V voltage, R9 and R10 are follower resistors of a comparator and control the comparator to output the voltage in an inverted mode, R3 is the pull-up resistor, VR2 is a sliding rheostat, a stable reference voltage is output to the inverted input end of U5B according to the processing of the reference voltage by the U5A follower, and C7 and C11 are ground isolation capacitors. As shown in fig. 4, a high-precision reference power supply U4 in the reference voltage module provides a 1.2V reference voltage for the circuit, R9 and R10 are follower resistors of a comparator, the comparator is controlled to output one to one, isolation and stabilization of the reference voltage are realized by a follower formed by two stages of operational amplifiers, R3 is a pull-up resistor, VR2 is a slide rheostat, voltage regulation of the same-phase input end of the comparator U5A between-1.2V and +1.2V is realized by regulating the slide rheostat, wide voltage range regulation is realized, and a stable reference voltage is output to the inverting input end of the U5B according to the processing of the reference voltage by the U5A follower.

The signal conditioning module comprises R5, R7, U5B, VR, VR3, C12, C13 and C14, wherein R5 is an input resistor, R7 is a feedback resistor, U5B is an operational amplifier, VR1 is a sliding variable resistance signal and is input by VR3, the resistance of VR1 is adjusted so as to adjust the amplifier multiple of the operational amplifier, and C12, C13 and C14 are ground isolation capacitors. As shown in FIG. 5, when a 1.2V reference voltage is inputted to the non-inverting input terminal of the amplifier, the resistance of VR1 is adjusted to adjust the amplification factor of the operational amplifier, and the operational amplifier amplifies the input voltage to output stable voltages of 0-5V and 0-10V.

The working principle is as follows: as shown in fig. 1, an isolated high-precision sensor voltage transmitter circuit includes a power input module, an isolation module, a reference voltage module, a signal conditioning module, and an output interface, as shown in fig. 2, D1 in the power input module is an anti-reverse diode, T1 is a TVS tube, and C1 is a power filter capacitor. U1 is a DCDC power supply chip and has the function of wide voltage input, R1 and R2 are precision resistors, C4 is an isolation capacitor to the ground, as shown in FIG. 3, an isolation module completely isolates a power supply from a signal, C3 is a filter capacitor, C2 and C5 are isolation capacitors to the ground, U2 is a power supply isolation module and can realize the isolation of the power supply from the ground and stably output 15V voltage, as shown in FIG. 4, a high-precision reference power supply U4 in a reference voltage module provides 1.2V reference voltage for a circuit, R9 and R10 are follower resistors of a comparator, the comparator is controlled to output one by one, the isolation and the stabilization of the reference voltage are realized through a follower formed by two stages of operational amplifiers, R3 is a pull-up resistor, VR2 is a slide rheostat, voltage of the same-phase input end of the comparator U5A is adjusted between-1.2V and +1.2V according to adjustment of the slide rheostat, wide voltage range adjustment is achieved, a stable reference voltage is output to the reverse-phase input end of the U5B according to processing of the reference voltage by the U5A follower, as shown in fig. 5, when the 1.2V reference voltage is input to the same-phase input end of the amplifier, the resistance value of the VR1 is adjusted, the amplifier multiple of the operational amplifier is adjusted, the operational amplifier amplifies the input voltage, and stable voltages of 0-5V and 0-10V can be output.

Claims

1. An isolated high-precision sensor voltage transmitter circuit is characterized by comprising a power input module, an isolation module, a reference voltage module, a signal conditioning module and an output interface;

the power input module comprises D1, T1, C1, U1, R2 and C4, wherein D1 is a diode, T1 is a TVS tube, C1 is a filter capacitor, U1 is a DC/DC power chip, R1 and R2 are precision resistors, C4 is a capacitor, the anode of D1 is connected with a power supply, the cathode is connected with the input voltage end of U1, T1 is connected between two power supply stages in parallel, C1 is connected between the cathode of D1 and one end of C4 in series, the other end of C4 is grounded, R1 is connected between the output voltage end of U1 and the state adjusting end in series, one end of R2 is connected with the state adjusting end of U1, and the other end of R2 is grounded;

the isolation module comprises C3, C2, C5 and U2, wherein C3 is a filter capacitor, C2 and C5 are capacitors, U2 is a power isolation module, C3 is connected in parallel between the positive electrode and the negative electrode of the input voltage end of U2, C2 is connected in series between the positive electrode of the output voltage end of U2 and the ground, C5 is connected in series between the negative electrode of the output voltage end of U2 and the ground, and the grounding end of U2 is grounded.

2. The isolated high-precision sensor voltage transmitter circuit as claimed in claim 1, wherein the reference voltage module comprises U4, R4, U3A, U3B, R, R10, R3, VR2, U5A and U5B, wherein U4 is a high-precision reference power supply and provides a reference voltage of 1.2V for the circuit, R4 is a pull-up resistor, U3A, U B forms a two-stage follower, U3A inverts the input +1.2V reference voltage to output a voltage of-1.2V, U3B inverts the voltage of-1.2V to output a voltage of +1.2V, R9 and R10 are follower resistors of a comparator, the comparator is controlled to output one to one, R3 is a pull-up resistor, VR2 is a sliding rheostat, a stable voltage is output to an input terminal of U5B according to the processing of the reference voltage by the U5A follower, and C7 and C11 are isolated reference capacitors.

3. The isolated high-precision sensor voltage transmitter circuit of claim 2, wherein the signal conditioning module comprises R5, R7, U5B, VR, VR3, C12, C13, C14, wherein R5 is an input resistor, R7 is a feedback resistor, U5B is an operational amplifier, VR1 is a sliding variable resistance signal input by VR3, the resistance of VR1 is adjusted to adjust the amplifier multiple of the operational amplifier, and C12, C13, C14 are isolated capacitors to ground.