CN104135275A - A signal isolator and a method for debugging the signal isolator - Google Patents
A signal isolator and a method for debugging the signal isolator Download PDFInfo
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Abstract
A signal isolator is disclosed according to embodiments of the invention. The signal isolator includes one isolation power supply module, one photoelectric coupling module, and one linear regulation module including a first resistor, a second resistor, a first variable resistor, and a second variable resistor, wherein, a first end of the first variable resistor is an input end of the linear regulation module to receive an output signal of the photoelectric coupling module, and a second end of the first variable resistor is grounded; a first end of the second variable resistor is grounded, and a second end of the second variable resistor receives a positive power supply; a first end of the first resistor is connected to a variable end of the first variable resistor, a second end of the first resistor is connected to a first end of the second resistor, a second end of the second resistor is connected to a variable end of the second variable resistor; and the second end of the first resistor is an output end of the linear regulation module to output an output signal of the signal isolator. According to the embodiments of the invention, the accuracy of linear relationship between the output signal and the input signal of the signal isolator is improved. A method for debugging the signal isolator is further disclosed according to the embodiments of the invention.
Description
Technical Field
The invention relates to the field of industrial measurement and control, in particular to a signal isolator and a method for debugging the signal isolator.
Background
In an industrial measurement and control site, an analog signal output from a sensor (or a meter, a micro control unit) is generally input into a central controller (or an actuator) after being subjected to signal isolation and conversion. The signal isolator can enable the central processing unit to accurately detect the analog signal output from the sensor and enable the central processing unit and the sensor to be electrically isolated.
The signal flow chart of the signal isolator used in the industrial measurement and control field is shown in figure 1. Wherein the ground on the left side of the signal isolator (i.e., GND1 in fig. 1) is electrically isolated from the ground on the right side (i.e., GND2 in fig. 1) and the power supply (i.e., VCC2 in fig. 1). The accuracy of the linear relationship between the output signal (i.e., VOUT in fig. 1) and the input signal (i.e., VIN in fig. 1) of the signal isolator over the entire span is very important.
At present, a signal isolator adopts V/F-F/V for isolation, that is, an input voltage signal is converted into a frequency signal through a V/F converter, the frequency signal is converted into a voltage signal through a pulse transformer, and finally the voltage signal is output, so that the function of voltage isolation output is achieved.
However, in consideration of cost, such a signal isolator generally needs to use a large number of operational amplifiers to construct the V/F converter, so that the signal isolator has many components, complex circuits, high failure rate and poor reliability. In addition, the signal isolator uses the pulse transformer, and due to the influence of the element parameters of the pulse transformer, the linear relationship between the output signal and the input signal of the signal isolator is poor (namely, the linear relationship between the output signal and the input signal with accurate five deviations cannot be ensured), and further, in the debugging stage of the signal isolator, the linear relationship between the output signal and the input signal is difficult to debug by engineering personnel.
The other signal isolator is isolated by adopting photoelectric coupling, namely the signal isolator is composed of an isolation power supply module and a photoelectric coupling module, wherein the main element in the photoelectric coupling module is a photoelectric coupling chip, and the isolation power supply module provides two sets of independent power supplies and grounds before and after isolation for the signal isolator, so that circuits on two sides of the photoelectric coupling chip in the photoelectric coupling module respectively use the power supplies and the grounds before and after isolation. Because a large number of operational amplifiers are not needed, the signal isolator has fewer elements, simpler circuit, lower failure rate and better reliability.
However, in the process of implementing the present invention, the inventors of the present invention found that at least the following problems exist in the prior art: even if a linear photoelectric coupling chip is adopted, the accuracy of the linear relation between the output signal and the input signal of the signal isolator has certain deviation due to the influence of the deviation of the linear photoelectric coupling chip in the process precision, the nonlinearity of other elements, the deviation of some resistance parameters and the like, and the required accuracy is difficult to achieve or even cannot be achieved.
Disclosure of Invention
In order to solve the above technical problems, embodiments of the present invention provide a signal isolator and a method for debugging the signal isolator, so as to improve accuracy of a linear relationship between an output signal and an input signal of the signal isolator, thereby enabling a debugging process to be simple and convenient.
The embodiment of the invention discloses the following technical scheme:
a signal isolator comprising, in addition to an isolated power supply module and an opto-electronic coupling module: a linear adjustment module, wherein,
the isolation power supply module is used for providing two sets of independent power supplies and grounds before and after isolation for the signal isolator, so that circuits on two sides of a photoelectric coupling chip in the photoelectric coupling module respectively use the power supplies and grounds before and after isolation;
the linear adjusting module comprises a first resistor, a second resistor, a first variable resistor and a second variable resistor;
the first end of the first variable resistor is the input end of the linear adjusting module, receives the output signal of the photoelectric coupling module, and the second end of the first variable resistor is grounded;
the first end of the second variable resistor is grounded, and the second end of the second variable resistor is connected with a positive power supply;
the first end of the first resistor is connected with the variable end of the first variable resistor, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is connected with the variable end of the second variable resistor;
and the second end of the first resistor is the output end of the linear adjusting module and outputs the output signal of the signal isolator.
Preferably, the first resistor and the second resistor have equal resistance values.
Preferably, the optoelectronic coupling module is a linear optoelectronic coupling module.
Preferably, the signal isolator further comprises: a first voltage follower module and a second voltage follower module, wherein,
the input end of the first voltage following module receives an input signal of the signal isolator, and the output end of the first voltage following module is connected with the input end of the photoelectric coupling module;
the input end of the second voltage following module is connected with the output end of the linear adjusting module, and the output end of the second voltage following module outputs the output signal of the signal isolator.
Preferably, the isolated power supply module includes: the power supply circuit comprises an isolated power supply chip, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor and a transient suppression diode, wherein,
the first end of the first capacitor is connected with the positive input end of the isolation power supply chip, and the second end of the first capacitor is connected with the negative input end of the isolation power supply chip;
the first end of the transient suppression diode is connected with the positive input end of the isolation power supply chip, and the second end of the transient suppression diode is connected with the negative input end of the isolation power supply chip;
the first end of the second capacitor is connected with the positive output end of the isolation power supply chip, and the second end of the second capacitor is connected with the grounding end of the isolation power supply chip;
the first end of the third capacitor is connected with the grounding end of the isolation power supply chip, and the second end of the third capacitor is connected with the negative output end of the isolation power supply chip;
the first end of the third resistor is connected with the positive output end of the isolation power supply chip, and the second end of the third resistor is connected with the grounding end of the isolation power supply chip;
the first end of the fourth resistor is connected with the grounding end of the isolation power supply chip, and the second end of the fourth resistor is connected with the negative output end of the isolation power supply chip;
the positive input end of the isolation power supply chip is connected with an external positive power supply, the negative input end of the isolation power supply chip is connected with an external ground, the positive output end outputs a positive power supply which is electrically isolated from the external positive power supply to the outside, the negative output end outputs a negative power supply which is electrically isolated from the external positive power supply to the outside, and the grounding end outputs a ground which is electrically isolated from the external ground to the outside.
Preferably, the linear photoelectric coupling module includes: a linear photoelectric coupling chip, a first operational amplifier, a second operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, a fourth capacitor and a fifth capacitor, wherein,
the first end of the fifth resistor is the input end of the linear photoelectric coupling module, and the second end of the fifth resistor is connected with the negative input end of the first operational amplifier;
the first end of the fourth capacitor is connected with the negative input end of the first operational amplifier, and the second end of the fourth capacitor is connected with the output end of the first operational amplifier;
the positive input end of the first operational amplifier is grounded;
the first end of the sixth resistor is connected with the output end of the first operational amplifier, and the second end of the sixth resistor is connected with the cathode of a light emitting diode in the linear photoelectric coupling chip;
the anode of a light emitting diode in the linear photoelectric coupling chip is connected with a positive power supply, the cathode of a first photosensitive diode in the linear photoelectric coupling chip is connected with the negative input end of the first operational amplifier, the anode of the first photosensitive diode is grounded, the cathode of a second photosensitive diode in the linear photoelectric coupling chip is connected with the negative input end of the second operational amplifier, and the anode of the second photosensitive diode is connected with the positive input end of the second operational amplifier;
the positive input end of the second operational amplifier is grounded;
the first end of the seventh resistor is connected with the negative input end of the second operational amplifier, and the second end of the seventh resistor is connected with the output end of the second operational amplifier;
and the first end of the fifth capacitor is connected with the negative input end of the second operational amplifier, the second end of the fifth capacitor is connected with the output end of the second operational amplifier, and the output end of the second operational amplifier is the output end of the linear photoelectric coupling module.
Preferably, the fifth resistor and the seventh resistor have the same resistance value.
Preferably, the first voltage following module or the second voltage following module includes: an eighth resistor, and a third operational amplifier, wherein,
a first end of the eighth resistor is an input end of the first voltage following module or the second voltage following module, and a second end of the eighth resistor is connected to a positive input end of the third operational amplifier;
the negative input end of the third operational amplifier is connected with the output end of the third operational amplifier, and the output end of the third operational amplifier is the output end of the first voltage following module or the second voltage following module.
A method of performing linear debug on any of the foregoing signal isolators, the method comprising:
setting the input voltage value of the signal isolator as the minimum value of a measuring range, and adjusting the resistance value of the first variable resistor until the output voltage value and the input voltage value of the signal isolator reach a preset linear relation;
resetting the input voltage value of the signal isolator to the maximum value in the range, and adjusting the resistance value of the second variable resistor until the output voltage value and the input voltage value of the signal isolator reach a preset linear relation.
Preferably, the range of the input voltage value is [0, 10 ].
As can be seen from the above embodiments, compared with the prior art, the present invention has the following advantages:
the accuracy of the linear relation between the output signal and the input signal of the signal isolator can be improved by correcting the photoelectric coupling module (especially a linear photoelectric coupling module) through the linear adjusting module.
In addition, the signal isolator does not use a large number of operational amplifiers, so that the circuit is simple, the failure rate is low, and the reliability is high.
In addition, since the signal isolator does not use a pulse transformer, the problem of zero drift does not exist.
Aiming at the signal isolator, only two-step debugging is carried out, so that the output signal and the input signal of the signal isolator have a set linear relation, and the debugging is simple and convenient.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a signal flow chart of a signal isolator used in an industrial measurement and control field;
FIG. 2 is a block diagram of one embodiment of a signal isolator of the present invention;
FIG. 3 is a block diagram of a linear conditioning module in the signal isolator of the present invention;
FIG. 4 is a block diagram of a linear opto-electronic coupling module in the signal isolator of the present invention;
FIG. 5 is a block diagram of another embodiment of a signal isolator according to the present invention;
FIG. 6 is a block diagram of a voltage follower module in the signal isolator of the present invention;
FIG. 7 is a block diagram of an isolated power module in the signal isolator of the present invention;
FIG. 8 is a flowchart of one embodiment of a method for debugging a signal isolator.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
Device embodiment
Referring to fig. 2, which is a structural diagram of an embodiment of a signal isolator according to the present invention, the signal isolator 20 includes, in addition to an isolation power module 21 and a spot coupling module 22, a linear adjustment module 23, and the isolation power module is configured to provide two sets of independent power supplies and grounds before and after isolation to the signal isolator, so that circuits on both sides of a photocoupling chip in the photocoupling module 22 respectively use the power supplies and grounds before and after isolation.
For example, the circuit on the left side of the photo coupling chip in the photo coupling module 22 uses the power and ground after isolation, while the circuit on the right side of the photo coupling chip in the photo coupling module 22 uses the power and ground before isolation. Of course, it is also possible that the circuit on the left side of the photocoupling chip in the photocoupling module 22 uses the power before isolation, and the circuit on the right side of the photocoupling chip in the photocoupling module 22 uses the power and ground after isolation.
As shown in fig. 3, taking as an example that a circuit on the left side of the photoelectric coupling chip in the photoelectric coupling module 22 uses a power supply (+ -15 v) and a ground (GND2) after isolation, and a circuit on the right side of the photoelectric coupling chip in the photoelectric coupling module 22 uses a power supply (+15v) and a ground (GND1) before isolation, the linear adjustment module 23 includes a resistor R1, a resistor R2 (the resistor R1 and the resistor R2 are resistors with fixed resistance values), a variable resistor R3 and a variable resistor R4;
the first end of the variable resistor R3 is the input end of the linear adjusting module 23, receives the output signal of the photoelectric coupling module 22, and the second end of the variable resistor R3 is grounded;
the first end of the variable resistor R4 is grounded, and the second end of the variable resistor R4 is connected with a positive power supply;
a first end of the resistor R1 is connected with a variable end of the variable resistor R3, a second end of the resistor R1 is connected with a first end of the resistor R2, and a second end of the resistor R2 is connected with a variable end of the variable resistor R4;
the second terminal of the resistor R1 is the output terminal of the linear adjusting module 23, which outputs the output signal of the signal isolator 20.
In a preferred embodiment of the present invention, the opto-electric coupling module 22 is a linear opto-electric coupling module.
Referring to fig. 4, which is a structural diagram of a linear photoelectric coupling module in a signal isolator according to the present invention, taking as an example that a circuit on the left side of a photoelectric coupling chip in a photoelectric coupling module 22 uses isolated power (+ -15 v) and ground (GND2), and a circuit on the right side of the photoelectric coupling chip in the photoelectric coupling module 22 uses isolated power (+15v) and ground (GND1), the linear photoelectric coupling module 30 includes: a linear photocoupling chip 31 (for example, HCNR200), an operational amplifier N1, an operational amplifier N2, a resistor R5, a resistor R6, a resistor R7, a capacitor C1, and a capacitor C2; wherein,
the first end of the resistor R5 is the input end of the linear photoelectric coupling module 30, and the second end of the resistor R5 is connected with the negative input end of the operational amplifier N1;
a first end of the capacitor C1 is connected with the negative input end of the operational amplifier N1, and a second end of the capacitor C1 is connected with the output end of the operational amplifier N1;
the positive input end of the operational amplifier N1 is grounded;
a first end of the resistor R6 is connected with the output end of the operational amplifier N1, and a second end of the resistor R6 is connected with the cathode of the light emitting diode (for example, 1 pin of HCNR200) in the linear photoelectric coupling chip 31;
an anode (for example, a 2 pin of the HCNR200) of a light emitting diode in the linear photocoupler chip 31 is connected with a positive power supply, a cathode (for example, a 3 pin of the HCNR200) of a first photodiode in the linear photocoupler chip 31 is connected with a negative input terminal of the operational amplifier N1, an anode (for example, a 4 pin of the HCNR200) of the first photodiode is grounded, a cathode (for example, a 6 pin of the HCNR200) of a second photodiode in the linear photocoupler chip 31 is connected with a negative input terminal of the operational amplifier N2, and an anode (for example, a 5 pin of the HCNR200) of the second photodiode is connected with a positive input terminal of the operational amplifier N2;
the positive input end of the operational amplifier N2 is grounded;
a first end of the resistor R7 is connected with the negative input end of the operational amplifier N2, and a second end of the resistor R7 is connected with the output end of the operational amplifier N2;
the first end of the capacitor C2 is connected to the negative input end of the operational amplifier N2, the second end of the capacitor C2 is connected to the output end of the operational amplifier N2, and the output end of the operational amplifier N2 is the output end of the linear photoelectric coupling module 30.
The operational amplifiers N1 and N2 may be TL074 or LM 358.
Obviously, for the linear photocoupling module 30, the output voltage (Vout1) and the input voltage (Vin1) have the following numerical relationship:
Vout1＝K3×R4/R2×Vin1
among them, K3 is determined by the process of the linear photocoupling chip itself, and is close to 1. If the resistances of the resistors R2 and R4 are equal, the output voltage Vout1 of the linear photocoupler module 30 is theoretically equal to Vin 1. However, due to the influence of the process precision deviation of the linear photoelectric coupling chip itself, the nonlinearity of other elements, the deviation of some resistance parameters, and the like, the ratio of Vout1 to Vin1 is generally between 0.9 and 1.1, that is, there is a certain deviation between the two, and the relationship is not completely accurate and linear. This deviation can be fully compensated for by the subsequent linear adjustment module.
It can be understood that, in the linear regulating module, a voltage dividing network is formed by the resistor R1, the resistor R2, the variable resistor R3 and the variable resistor R4. If the linear relationship between the input voltage and the output voltage of the linear regulation module 23 is: vout2 is kVin2+ b, where Vin2 is the input voltage of the linear regulator module 23, Vout3 is the output voltage of the linear regulator module, and the values of k and b can be adjusted by adjusting the variable resistors R3 and R4, so that a predetermined linear relationship is achieved between the total input voltage and the total output voltage of the entire signal isolator.
It should be noted that, in the technical solution of the present invention, the isolation power supply module provides electrically isolated power supplies for circuits on the left and right sides of the photoelectric coupling chip, and any one of the isolation power supply modules in the prior art may be adopted, and the internal structure of the isolation power supply module will be described in detail later.
In order to further avoid the interference of the signal isolator to other circuits in the system shown in fig. 1, it is more preferable to increase the input impedance of the whole signal isolator and decrease the output impedance of the whole signal isolator. Therefore, a voltage follower module is required to be respectively arranged at the frontmost end and the rearmost end of the signal isolator. Fig. 5 is a block diagram of another embodiment of a signal isolator according to the present invention. Wherein, the signal isolator 20 further comprises: a first voltage following module 24 and a second voltage following module 25; wherein,
the input end of the first voltage following module 24 receives the input signal of the signal isolator, and the output end of the first voltage following module 24 is connected with the input end of the photoelectric coupling module 22;
the input end of the second voltage following module 24 is connected to the output end of the linear adjusting module, and the output end of the second voltage following module 24 outputs the output signal of the signal isolator.
It can be understood that when a voltage follower module 25 is disposed after the linear regulation module 23, the output voltage of the linear regulation module is 0, and if the second terminal of the variable resistor R4 receives +15v of dc voltage, it can be derived from KCL law:
(15 × Zero-Vout3)/R2 ═ Vout-Vin3 × Scale)/R1; where Vin3 is the input voltage of the linear regulator module 23, Vout3 is the output voltage of the linear regulator module, and Scale and Zero are the voltage division ratios of the variable resistors R3 and R4, respectively.
In another preferred embodiment of the present invention, the resistances of the resistors R1 and R2 are equal. Thus, by working up the above formula, one can obtain:
Vout3＝Scale/2×Vin3+Zero/2×15
it can be observed that Vout3 is a linear function of Vin3, and the output voltage Vout2 of the linear photocoupler module 22 is also an approximately linear function of the input voltage Vin2, so that the total output and the total input of the signal isolator circuit can satisfy a predetermined linear function relationship by adjusting the variable resistors R3 and R4. Assuming that Vin ranges from 0-10V, Vout can output 0-12.5V by adjusting the variable resistors R3 and R4.
It should be noted that, in the technical solution of the present invention, any voltage follower module in the prior art may be used. For example, as shown in fig. 6, the voltage following module 50 includes: a resistor R8 and an operational amplifier N3; wherein,
the first end of the resistor R8 is the input end of the voltage follower module 50, and the second end of the resistor R8 is connected to the positive input end of the operational amplifier N3;
the negative input terminal of the operational amplifier N3 is connected to the output terminal of the operational amplifier N3, and the output terminal of the operational amplifier N3 is the output terminal of the voltage follower module 50.
In an embodiment of the present invention, an implementation manner of an isolated power supply module is provided. Please refer to fig. 7, which is a structural diagram of an isolation power module in a signal isolator according to the present invention. In fig. 7, the power and ground of the isolated power module before isolation are +15v and GND1, respectively, and the power and ground after isolation are ± 15v and GND2, respectively. Wherein the linear photo coupling module 60 includes: an isolation power chip 61 (e.g., DCP01515DB), a resistor R9, a resistor R10, a capacitor C3, a capacitor C4, a capacitor C5, and a transient suppression diode V1 (e.g., P6KE18 CA); wherein,
a first end of the capacitor C3 is connected to the positive input terminal of the isolation power supply chip 61 (for example, pin 1 of DCP01515DB), and a second end of the capacitor C3 is connected to the negative input terminal of the isolation power supply chip 61 (for example, pin 2 of DCP01515 DB);
a first end of the transient suppression diode V1 is connected with the positive input end of the isolation power supply chip 61, and a second end of the transient suppression diode V1 is connected with the negative input end of the isolation power supply chip;
a first terminal of the capacitor C4 is connected to the positive output terminal of the isolated power chip 61 (e.g., pin 6 of DCP01515DB), and a second terminal of the capacitor C4 is connected to the ground terminal of the isolated power chip 61 (e.g., pin 5 of DCP01515 DB);
a first end of the capacitor C5 is connected to the ground terminal of the isolated power chip 61, and a second end of the capacitor C5 is connected to the negative output terminal of the isolated power chip 61 (for example, pin 7 of DCP01515 DB);
a first end of the resistor R9 is connected with the positive output end of the isolation power supply chip 61, and a second end of the resistor R9 is connected with the ground end of the isolation power supply chip 61;
the first end of the resistor R10 is connected with the grounding end of the isolation power supply chip 61, and the second end of the resistor R10 is connected with the negative output end of the isolation power supply chip 61;
the positive input terminal of the isolated power supply chip 61 is connected to an external positive power supply, the negative input terminal is connected to an external ground, the positive output terminal outputs a positive power supply electrically isolated from the external positive power supply to the outside, the negative output terminal outputs a negative power supply electrically isolated from the external positive power supply to the outside, and the ground terminal outputs a ground electrically isolated from the external ground to the outside.
For example, the positive input terminal of the isolated power supply chip 61 is connected to an external positive power supply of +15v, the negative input terminal is connected to an external analog ground GND1, a ± 15v power supply electrically isolated from the external positive power supply of +15v is output to the outside from the positive output terminal and the negative output terminal of the isolated power supply chip 61, and the ground terminal outputs to the outside an analog ground GND2 electrically isolated from an external analog ground GND 1. All circuits on the right side of the linear photoelectric coupling chip can use an external +15v power supply and GND1 for power supply, all circuits on the left side of the linear photoelectric coupling chip can use a +/-15 v power supply and GND2 for power supply output by the isolation power chip 61, and finally isolation on the power supply is realized.
As can be seen from the above embodiments, compared with the prior art, the present invention has the following advantages:
the accuracy of the linear relation between the output signal and the input signal of the signal isolator can be improved by correcting the photoelectric coupling module (especially a linear photoelectric coupling module) through the linear adjusting module.
In addition, the signal isolator does not use a large number of operational amplifiers, so that the circuit is simple, the failure rate is low, and the reliability is high.
In addition, since the signal isolator does not use a pulse transformer, the problem of zero drift does not exist.
Aiming at the signal isolator, only two-step debugging is carried out, so that the output signal and the input signal of the signal isolator have a set linear relation, and the debugging is simple and convenient.
Method embodiment
Referring to fig. 8, which is a flowchart of an embodiment of a method for debugging a signal isolator according to the present invention, the method includes the following steps:
step 801: the input voltage value of the signal isolator is set to be the minimum value in the range of the measuring range, and the variable resistor R4 is adjusted until the output voltage value and the input voltage value of the signal isolator reach the preset linear relation.
Step 802: the input voltage value of the signal isolator is reset to the maximum value in the range of the measuring range, and the variable resistor R3 is adjusted until the preset linear relation between the output voltage value and the input voltage value of the signal isolator is achieved.
For example, the range of the input voltage value of the signal isolator is 0-10V, and the preset linear relationship between the output voltage and the input voltage is as follows:
vout total 0.5 Xvin
That is, when the input voltage is 0v, the output voltage is 0v, and when the input voltage is 10v, the output voltage is 5 v.
The input voltage value is first set to 0v and R4 is adjusted while monitoring the output voltage value until it is 0 v. Thereafter, the input voltage value is again reset to 10v, and R3 is adjusted while monitoring the output voltage value until 5 v. Therefore, the circuit debugging can be completed through two steps, and the debugging is very simple.
For the debugged signal isolator, the relative output voltage is monitored by inputting different voltages, and the data of the two are shown in the following table. The error between the actual output voltage value and the ideal output voltage value is less than 0.5 percent in the whole range, and the ideal performance is presented.
It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the embodiments provided in the present invention, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when the actual implementation is performed, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not performed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or units through some interfaces, and may be in an electrical, mechanical or other form.
The units described as separate parts may be or may be physically separate, and parts displayed as units may be or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can be realized in a form of a software functional unit.
It should be noted that, as will be understood by those skilled in the art, all or part of the processes in the methods of the above embodiments may be implemented by a computer program, which may be stored in a computer-readable storage medium, and when executed, may include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), or the like.
The signal isolator and the method for debugging the signal isolator provided by the invention are described in detail above, and the principle and the implementation mode of the invention are explained by applying specific embodiments in the text, and the description of the embodiments is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (10)
1. A signal isolator comprising an isolated power module and an opto-electronic coupling module, said signal isolator further comprising: a linear adjustment module, wherein,
the isolation power supply module is used for providing two sets of independent power supplies and grounds before and after isolation for the signal isolator, so that circuits on two sides of a photoelectric coupling chip in the photoelectric coupling module respectively use the power supplies and grounds before and after isolation;
the linear adjusting module comprises a first resistor, a second resistor, a first variable resistor and a second variable resistor;
the first end of the first variable resistor is the input end of the linear adjusting module, receives the output signal of the photoelectric coupling module, and the second end of the first variable resistor is grounded;
the first end of the second variable resistor is grounded, and the second end of the second variable resistor is connected with a positive power supply;
the first end of the first resistor is connected with the variable end of the first variable resistor, the second end of the first resistor is connected with the first end of the second resistor, and the second end of the second resistor is connected with the variable end of the second variable resistor;
and the second end of the first resistor is the output end of the linear adjusting module and outputs the output signal of the signal isolator.
2. The signal isolator of claim 1, wherein the first and second resistors are equal in value.
3. The signal isolator of claim 1, wherein the opto-electronic coupling module is a linear opto-electronic coupling module.
4. The signal isolator of claim 1, further comprising: a first voltage follower module and a second voltage follower module, wherein,
the input end of the first voltage following module receives an input signal of the signal isolator, and the output end of the first voltage following module is connected with the input end of the photoelectric coupling module;
the input end of the second voltage following module is connected with the output end of the linear adjusting module, and the output end of the second voltage following module outputs the output signal of the signal isolator.
5. The signal isolator of claim 1, wherein the isolated power supply module comprises: the power supply circuit comprises an isolated power supply chip, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor and a transient suppression diode, wherein,
the first end of the first capacitor is connected with the positive input end of the isolation power supply chip, and the second end of the first capacitor is connected with the negative input end of the isolation power supply chip;
the first end of the transient suppression diode is connected with the positive input end of the isolation power supply chip, and the second end of the transient suppression diode is connected with the negative input end of the isolation power supply chip;
the first end of the second capacitor is connected with the positive output end of the isolation power supply chip, and the second end of the second capacitor is connected with the grounding end of the isolation power supply chip;
the first end of the third capacitor is connected with the grounding end of the isolation power supply chip, and the second end of the third capacitor is connected with the negative output end of the isolation power supply chip;
the first end of the third resistor is connected with the positive output end of the isolation power supply chip, and the second end of the third resistor is connected with the grounding end of the isolation power supply chip;
the first end of the fourth resistor is connected with the grounding end of the isolation power supply chip, and the second end of the fourth resistor is connected with the negative output end of the isolation power supply chip;
the positive input end of the isolation power supply chip is connected with an external positive power supply, the negative input end of the isolation power supply chip is connected with an external ground, the positive output end outputs a positive power supply which is electrically isolated from the external positive power supply to the outside, the negative output end outputs a negative power supply which is electrically isolated from the external positive power supply to the outside, and the grounding end outputs a ground which is electrically isolated from the external ground to the outside.
6. The signal isolator of claim 3, wherein the linear optocoupler module comprises: a linear photoelectric coupling chip, a first operational amplifier, a second operational amplifier, a fifth resistor, a sixth resistor, a seventh resistor, a fourth capacitor and a fifth capacitor, wherein,
the first end of the fifth resistor is the input end of the linear photoelectric coupling module, and the second end of the fifth resistor is connected with the negative input end of the first operational amplifier;
the first end of the fourth capacitor is connected with the negative input end of the first operational amplifier, and the second end of the fourth capacitor is connected with the output end of the first operational amplifier;
the positive input end of the first operational amplifier is grounded;
the first end of the sixth resistor is connected with the output end of the first operational amplifier, and the second end of the sixth resistor is connected with the cathode of a light emitting diode in the linear photoelectric coupling chip;
the anode of a light emitting diode in the linear photoelectric coupling chip is connected with a positive power supply, the cathode of a first photosensitive diode in the linear photoelectric coupling chip is connected with the negative input end of the first operational amplifier, the anode of the first photosensitive diode is grounded, the cathode of a second photosensitive diode in the linear photoelectric coupling chip is connected with the negative input end of the second operational amplifier, and the anode of the second photosensitive diode is connected with the positive input end of the second operational amplifier;
the positive input end of the second operational amplifier is grounded;
the first end of the seventh resistor is connected with the negative input end of the second operational amplifier, and the second end of the seventh resistor is connected with the output end of the second operational amplifier;
and the first end of the fifth capacitor is connected with the negative input end of the second operational amplifier, the second end of the fifth capacitor is connected with the output end of the second operational amplifier, and the output end of the second operational amplifier is the output end of the linear photoelectric coupling module.
7. The signal isolator of claim 6, wherein the fifth resistor and the seventh resistor have equal resistance values.
8. The signal isolator of claim 2, wherein the first or second voltage follower module comprises: an eighth resistor, and a third operational amplifier, wherein,
a first end of the eighth resistor is an input end of the first voltage following module or the second voltage following module, and a second end of the eighth resistor is connected to a positive input end of the third operational amplifier;
the negative input end of the third operational amplifier is connected with the output end of the third operational amplifier, and the output end of the third operational amplifier is the output end of the first voltage following module or the second voltage following module.
9. A method of linear debugging a signal isolator according to any one of claims 1 to 8, the method comprising:
setting the input voltage value of the signal isolator as the minimum value of a measuring range, and adjusting the resistance value of the first variable resistor until the output voltage value and the input voltage value of the signal isolator reach a preset linear relation;
resetting the input voltage value of the signal isolator to the maximum value in the range, and adjusting the resistance value of the second variable resistor until the output voltage value and the input voltage value of the signal isolator reach a preset linear relation.
10. The method of claim 9 wherein the input voltage value has a span of [0, 10 ].
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