CN212135198U - A drive control system and signal conditioning and protection circuit - Google Patents

Abstract

The application provides a drive control system and a signal conditioning and protection circuit, which belong to the technical field of drive control. The drive control system includes: a signal conditioning and protection circuit, a controller, a logic chip, a drive circuit, a load, and a current sensor. The output ends of the signal conditioning and protection circuit are respectively connected to the controller and the logic chip; the output end of the controller is connected to the logic chip. The chip is connected; the output end of the logic chip is connected with the drive circuit; the output end of the drive circuit is connected with the load. Among them, the logic chip does not need to perform AD conversion on the conditioned digital signal, which reduces the judgment time, and can control the driving circuit in time to avoid damage to the driving circuit and the load.

Description

A drive control system and signal conditioning and protection circuit

technical field

The present application relates to the technical field of drive control, and in particular, to a drive control system and a signal conditioning and protection circuit.

Background technique

The most common form of damage to the drive circuit is overcurrent damage. Therefore, it is particularly important to protect the drive circuit from overcurrent, so that the drive circuit can drive the load to work under safe conditions.

In the prior art, the current sensor collects the output signal of the drive circuit, and after the collected output signal of the drive circuit is processed by an operational amplifier, the operational amplifier outputs an analog signal, the controller receives the analog signal, and judges whether it is abnormal through software according to the analog signal, When the analog signal is abnormal, it means that the output signal of the driving circuit is abnormal, the controller can cut off the output driving signal, and the driving circuit and the load stop working.

However, in the process of software judging the abnormality of the analog signal, AD (analog-to-digital) conversion and controller processing need to wait for a long time, which makes it take a long time to judge the abnormality of the analog signal, delays cutting off the driving signal, and leads to the control of the driving circuit. If it is not in time, the drive circuit and the load will be damaged.

Utility model content

The purpose of this utility model is to provide a drive control system and a signal conditioning and protection circuit, which can solve the problem of delaying cutting off the drive signal in the prior art, resulting in untimely control of the drive circuit and damage to the drive circuit and the load.

An embodiment of the present utility model provides a drive control system, including: a signal conditioning and protection circuit, a controller, a logic chip, a drive circuit, a load, and a current sensor;

The output end of the signal conditioning and protection circuit is respectively connected with the controller and the logic chip; the output end of the controller is connected with the logic chip; the output end of the logic chip is connected with the drive circuit ; The output end of the drive circuit is connected to the load;

The current sensor is arranged between the output end of the driving circuit and the load, and is connected to the signal conditioning and protection circuit for collecting the output signal of the driving circuit and reporting the signal conditioning and protection to the signal conditioning and protection circuit. a circuit to send the output signal of the drive circuit;

The signal conditioning and protection circuit is used for conditioning the output signal of the driving circuit, sending the conditioned digital signal to the logic chip, and sending the conditioned analog signal to the controller;

the controller, configured to output a drive signal to the logic chip according to the conditioned analog signal;

The logic chip is configured to control the drive circuit to drive the load according to the drive signal and the digital signal.

Optionally, the signal conditioning and protection circuit is specifically configured to output a low-level signal to the logic chip when the conditioned digital signal is greater than a preset protection threshold; when the conditioned digital signal is less than or equal to the preset protection threshold, output a high-level signal to the logic chip.

Optionally, the signal conditioning and protection circuit includes: a follower circuit and a signal comparison circuit; the follower circuit includes: an operational amplifier;

The forward input terminal of the operational amplifier is connected to the output terminal of the current sensor; the reverse input terminal of the operational amplifier is grounded;

The first output end of the operational amplifier is connected to the input end of the signal comparison circuit;

the second output terminal of the operational amplifier is connected to the input terminal of the controller;

The output end of the signal comparison circuit is connected with the input end of the logic chip.

Optionally, the signal comparison circuit includes: a first comparator, a second comparator, a positive overcurrent threshold circuit and a negative overcurrent threshold circuit;

The forward input terminal of the first comparator and the reverse input terminal of the second comparator are respectively connected to the first output terminal of the operational amplifier, and the reverse input terminal of the first comparator is connected to the The output terminal of the positive overcurrent threshold circuit is connected, and the positive input terminal of the second comparator is connected to the output terminal of the negative overcurrent threshold circuit.

Optionally, the follower circuit further includes: a first resistor, a second resistor, a first capacitor, and a second capacitor;

The output end of the current sensor is connected to the first resistor and the second resistor respectively, and the other end of the second resistor is respectively connected to the forward input end of the operational amplifier and one end of the first capacitor , the other end of the first capacitor is connected to ground;

One end of the second capacitor is connected to the positive power supply terminal of the operational amplifier, and the negative power supply terminal of the operational amplifier is connected to the ground; the other end of the second capacitor is connected to the ground.

Optionally, the signal comparison circuit further includes: a third resistor, a fourth resistor, and a third capacitor;

The first output end of the operational amplifier is respectively connected to one end of the third resistor and one end of the fourth resistor;

One end of the third capacitor is connected to one end of the third resistor, and the other end of the third capacitor is grounded to the other end of the fourth resistor.

Optionally, the controller is a single-chip microcomputer.

Optionally, the current sensor is a Hall sensor, the load is a three-phase motor, and the motor inputs a three-phase current signal; the drive circuit outputs a three-phase current signal;

The Hall sensors respectively collect the three-phase current signals output by the driving circuit.

Another aspect of the present utility model provides a signal conditioning and protection circuit, comprising: a follower circuit and a signal comparison circuit; the follower circuit comprises: an operational amplifier;

The forward input terminal of the operational amplifier is used to receive the input signal, and the reverse input terminal of the operational amplifier is grounded;

The first output end of the operational amplifier is connected to the input end of the signal comparison circuit;

The second output end of the operational amplifier is used to output the conditioned analog signal; the signal comparison circuit is used to output the conditioned digital signal.

Optionally, the signal comparison circuit includes: a first comparator, a second comparator, a positive overcurrent threshold circuit and a negative overcurrent threshold circuit;

The forward input terminal of the first comparator and the reverse input terminal of the second comparator are respectively connected to the first output terminal of the operational amplifier, and the reverse input terminal of the first comparator is connected to the The output terminal of the positive overcurrent threshold circuit is connected, and the positive input terminal of the second comparator is connected to the output terminal of the negative overcurrent threshold circuit.

The beneficial effects of the embodiments of the present utility model include:

In the drive control system and the signal conditioning and protection circuit provided by the embodiment of the present invention, the output ends of the signal conditioning and protection circuits are respectively connected with the controller and the logic chip; the output end of the controller is connected with the logic chip; the output end of the logic chip is connected with the logic chip. connected with the drive circuit; the output end of the drive circuit is connected with the load; the current sensor is arranged between the output end of the drive circuit and the load, and is connected with the signal conditioning and protection circuit to collect the output signal of the drive circuit and send it to the signal conditioning The output signal of the drive circuit is sent with the protection circuit. Wherein, based on the received conditioned digital signal, the logic chip can determine whether the received conditioned digital signal type is consistent with the preset signal type, if so, the logic chip outputs the drive signal to the drive circuit; When the output driving signal is cut off, the logic chip does not need to perform AD conversion on the conditioned digital signal, which reduces the judgment time, and can control the driving circuit in time to avoid damage to the driving circuit and the load.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention. Therefore, it should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of a drive control system provided by an embodiment of the present invention;

2 is a schematic partial circuit diagram of a signal conditioning and protection circuit provided by an embodiment of the present invention;

3 is a schematic partial circuit diagram of a signal conditioning and protection circuit provided by an embodiment of the present invention;

FIG. 4 is a schematic circuit diagram of a signal conditioning and protection circuit provided by an embodiment of the present invention.

Icon: Signal Conditioning and Protection Circuit-101; Operational Amplifier-U1A; Signal Comparison Circuit-1012; First Comparator-U2A; Second Comparator-U2B; Positive Overcurrent Threshold Circuit-10123; Negative Overcurrent Threshold Circuit-10124 ; controller-102; logic chip-103; drive circuit-104; load-105; current sensor-106; first resistor-R2; second resistor-R3; first capacitor-C1; second capacitor-C2; Three capacitors-C3; third resistor-R4; fourth resistor-R6; fifth resistor-R9; sixth resistor-R10; fourth capacitor-C7; seventh resistor-R11; eighth resistor-R12; fifth capacitor -C8.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. The embodiments described above are a part of the embodiments of the present invention, but not all of the embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that like numerals and letters refer to like items in the following figures, so once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. Furthermore, the terms "first", "second", "third", etc. are only used to differentiate the description and should not be construed as indicating or implying relative importance.

FIG. 1 is a schematic structural diagram of a drive control system provided by the present invention. Please refer to FIG. 1. The drive control system includes: a signal conditioning and protection circuit 101, a controller 102, a logic chip 103, a drive circuit 104, a load 105, Current sensor 106 .

The output end of the signal conditioning and protection circuit 101 is connected to the controller 102 and the logic chip 103 respectively; the output end of the controller 102 is connected to the logic chip 103; the output end of the logic chip 103 is connected to the driving circuit 104; The output terminal is connected to the load 105; the current sensor 106 is arranged between the output terminal of the driving circuit 104 and the load 105, and is connected to the signal conditioning and protection circuit 101 for collecting the output signal of the driving circuit 104 and providing the signal conditioning and protection The circuit 101 transmits the output signal of the drive circuit 104 .

The signal conditioning and protection circuit 101 is used for conditioning the output signal of the driving circuit 104, sending the conditioned digital signal to the logic chip 103, and sending the conditioned analog signal to the controller 102; the controller 102 is used to adjust the conditioned analog signal according to the The signal outputs a drive signal to the logic chip 103; the logic chip 103 is used to control the drive circuit 104 to drive the load 105 according to the drive signal.

The load 105 may be a motor or other loads, which are not limited in the embodiment of the present invention.

The working process of the drive control system is described in detail as follows:

When the drive control system works, the current sensor 106 collects the output signal of the drive circuit 104 and sends the output signal of the drive circuit 104 to the signal conditioning and protection circuit 101 . The signal conditioning and protection circuit 101 adjusts the output signal of the drive circuit 104 after conditioning , send the conditioned digital signal to the logic chip 103, and send the conditioned analog signal to the controller 102, the controller 102 can output the driving signal to the logic chip 103 according to the conditioned analog signal, the logic chip 103 forwards the driving signal, and passes the The driving signal controls the driving circuit 104 to drive the load 105 to work.

When the type of the conditioned digital signal output by the signal conditioning and protection circuit 101 is inconsistent with the preset signal type, at this time, the logic chip 103 can cut off the output of the driving signal to the driving circuit 104, although the controller 102 still sends the logic The chip 103 transmits the driving signal, but the logic chip 103 cuts off the output of the driving signal to the driving circuit 104 according to the conditioned digital signal, thereby protecting the driving circuit 104 and the load 105 .

When the type of the conditioned digital signal output by the signal conditioning and protection circuit 101 is consistent with the preset signal type, the logic chip 103 can control the driving circuit 104 to drive the load 105 to work through the driving signal.

To sum up, in the drive control system provided by the embodiment of the present invention, the output ends of the signal conditioning and protection circuits are respectively connected to the controller and the logic chip; the output end of the controller is connected to the logic chip; the output end of the control chip is connected to the logic chip. The drive circuit is connected; the output end of the drive circuit is connected to the load; the current sensor is arranged between the output end of the drive circuit and the load, and is connected to the signal conditioning and protection circuit for collecting the output signal of the drive circuit and sending it to the signal conditioning and protection circuit. The protection circuit transmits the output signal of the driving circuit. The output signal of the drive circuit is conditioned by the signal conditioning protection circuit, and after conditioning, the conditioned digital signal is sent to the logic chip, and the conditioned analog signal is sent to the controller, and the controller outputs the drive to the logic chip according to the conditioned analog signal. Signal. Wherein, based on the received conditioned digital signal, the logic chip can determine whether the received conditioned digital signal type is consistent with the preset signal type, if so, the logic chip outputs the drive signal to the drive circuit; When the output driving signal is cut off, the logic chip does not need to perform AD conversion on the conditioned digital signal, which reduces the judgment time, and can control the driving circuit in time to avoid damage to the driving circuit and the load.

Optionally, what the current sensor 106 collects is the output signal of the driving circuit 104, and the output signal of the driving circuit 104 may be a current signal. The output signal is a voltage signal. Correspondingly, the output signal of the driving circuit 104 input by the signal conditioning and protection circuit 101 is a voltage signal.

Optionally, the driving circuit 104 is an IGBT (Insulated Gate Bipolar Transistor, insulated gate bipolar transistor) driving circuit 104 . IGBT has the advantages of easy driving, simple control and high switching frequency of FET, and can be widely used in many fields. For example, IGBT can be widely used in the field of electric vehicles.

The following describes the output of the conditioned digital signal from the signal conditioning and protection circuit 101 to the logic chip 103 in detail.

Optionally, the signal conditioning and protection circuit 101 is specifically used to output a low-level signal to the logic chip 103 when the output signal of the drive circuit 104 is greater than the preset protection threshold; when the output signal of the drive circuit 104 is less than or equal to the preset When the protection threshold is set, a high level signal is output to the logic chip 103 .

When the signal conditioning and protection circuit 101 outputs a low-level signal, it means that the output signal of the driving circuit 104 is abnormal. At this time, the logic chip 103 can immediately cut off the output driving signal according to the low-level signal, preventing the controller 102 from still outputting the output signal due to the delay. The driving signal causes the untimely control of the driving circuit 104 , resulting in damage to the driving circuit 104 and the load 105 .

When the signal conditioning and protection circuit 101 outputs a high-level signal, the logic chip 103 determines that the output signal of the driving circuit 104 is not abnormal according to the high-level signal. At this time, the driving signal sent by the controller 102 can be forwarded to the driving circuit 104. The drive signal output by the chip 103 controls the drive circuit 104 to drive the load 105 , thereby realizing the drive control of the load 105 .

In the embodiment of the present invention, the protection of the driving circuit 104 and the load 105 is realized by means of double protection, wherein the above-mentioned logic chip 103 receives the conditioned digital signal, and the logic chip 103 determines whether to cut off the conditioned digital signal according to the conditioned digital signal. The logic chip 103 outputs driving signals.

In addition, after the controller 102 receives the conditioned analog signal, it can also determine whether the conditioned analog signal is abnormal. If it is abnormal, the controller 102 will cut off the output driving signal. Under the double protection, the abnormal output signal of the driving circuit 104 can be avoided. At the time, the drive circuit 104 receives the drive signal, and drives the load 105 to work according to the drive signal, causing damage to the drive circuit 104 and the load 105 .

FIG. 2 is a schematic partial circuit diagram of a signal conditioning and protection circuit 101 provided by an embodiment of the present invention; as shown in FIG. 2 , optionally, the signal conditioning and protection circuit 101 includes: a follower circuit and a signal comparison circuit 1012; The follower circuit includes: an operational amplifier U1A; the forward input terminal of the operational amplifier U1A is connected to the output terminal of the current sensor 106 ; the reverse input terminal of the operational amplifier U1A is grounded; the first output terminal of the operational amplifier U1A is connected to the signal comparison circuit 1012 . The input end is connected; the second output end of the operational amplifier U1A is connected with the input end of the controller 102 ; the output end of the signal comparison circuit 1012 is connected with the input end of the logic chip 103 .

The output signal of the driving circuit 104 output by the current sensor 106 is in the form of a voltage signal, and the current sensor 106 can transmit the collected output signal of the driving circuit 104 to the operational amplifier U1A, and the operational amplifier U1A receives the output signal of the driving circuit 104 and transmits the output signal of the driving circuit 104 to the operational amplifier U1A. The conditioned analog signal is sent to the signal comparison circuit 1012 and the controller 102 . After receiving the conditioned analog signal, the signal comparison circuit 1012 processes the conditioned analog signal and sends the conditioned digital signal to the logic chip 103; the controller 102 receives the conditioned analog signal, and sends the conditioned analog signal to the logic chip 103. The logic chip 103 outputs driving signals.

Optionally, the follower circuit further includes: a first resistor R2, a second resistor R3, a first capacitor C1, and a second capacitor C2; the output end of the current sensor 106 is connected to the first resistor R2 and the second resistor R3 respectively, and the first resistor R2 and the second resistor R3 are respectively connected. The other end of the two resistors R3 is respectively connected to the positive input end of the operational amplifier U1A and one end of the first capacitor C1, the other end of the first capacitor C1 is connected to ground; one end of the second capacitor C2 is connected to the positive power supply end of the operational amplifier U1A , the negative power supply terminal of the operational amplifier U1A is connected to the ground; the other terminal of the second capacitor C2 is connected to the ground.

As shown in FIG. 2 , the first resistor R2, the second resistor R3, the first capacitor C1, and the second capacitor C2 constitute a follower circuit. The role of the follower circuit is to enhance the driving ability of the signal and play a certain role of isolation between the front and rear stages.

When the follower circuit works, the output signal of the driving circuit 104 output by the current sensor 106 is in the form of a voltage signal. The output signal of the driving circuit 104 passes through the first resistor R2 and the second resistor R3 to the non-inverting input terminal of the operational amplifier U1A.

Optionally, the current sensor 106 is a Hall sensor, the load 105 is a three-phase motor, and the motor inputs three-phase current signals; the drive circuit 104 outputs three-phase current signals.

The range of the Hall sensor may be, but not limited to, 800A. When the range of the Hall sensor is 800A, when there is no current flowing, it outputs 2.5V, and when there is current passing through, it outputs a sine wave signal with 2.5V as the reference point according to the magnitude of the current. The maximum output range of the voltage is 0.5 V-4.5V.

When the load 105 is a three-phase motor, the drive circuit 104 outputs a three-phase current signal, and the Hall sensor is arranged between the drive circuit 104 and the three-phase motor, and is used to collect each phase current signal output by the drive circuit 104. A phase current signal is sent to the signal conditioning and protection circuit 101 .

FIG. 3 is a schematic partial circuit diagram of a signal conditioning and protection circuit 101 provided by an embodiment of the present invention. Referring to FIG. 3 , optionally, the controller 102 is a single-chip microcomputer.

When the controller 102 is a single-chip microcomputer, the single-chip microcomputer belongs to an integrated circuit chip. The circuit chip integrates data operation and processing capabilities into the chip through the application of integrated circuit technology, and can realize high-speed data processing.

4 is a schematic circuit diagram of a signal conditioning and protection circuit 101 provided by an embodiment of the present invention; with reference to FIG. 4 , optionally, the signal comparison circuit 1012 includes: a first comparator U2A, a second comparator U2B, a positive-pass The current threshold circuit 10123 and the negative overcurrent threshold circuit 10124; the forward input terminal of the first comparator U2A and the reverse input terminal of the second comparator U2B are respectively connected to the first output terminal of the operational amplifier U1A, and the first comparator U2A The inverting input terminal of the second comparator U2B is connected to the output terminal of the positive overcurrent threshold circuit 10123 , and the positive input terminal of the second comparator U2B is connected to the output terminal of the negative overcurrent threshold circuit 10124 .

The output terminals of the first comparator U2A and the second comparator U2B are both connected to the logic chip 103 . The positive overcurrent threshold circuit 10123 constitutes the positive overcurrent threshold in the form of a circuit; the negative overcurrent threshold circuit 10124 constitutes the negative overcurrent threshold in the form of a circuit, and both the positive overcurrent threshold and the negative overcurrent threshold refer to the preset protection threshold.

As shown in FIG. 4 , the positive overcurrent threshold circuit 10123 may be composed of a fifth resistor R9, sixth resistors R10-R10 and a fourth capacitor C7; the negative overcurrent threshold circuit 10124 may be composed of a seventh resistor R11, an eighth resistor R12 and The fifth capacitor C8 is formed.

The first comparator U2A receives the conditioned analog signal, and compares the conditioned analog signal with the positive overcurrent threshold. When the conditioned analog signal input by the first comparator U2A is greater than the positive overcurrent threshold, it outputs a low voltage. A high-level signal is output when the conditioned analog signal input by the first comparator U2A is less than or equal to the positive overcurrent threshold.

The second comparator U2B receives the conditioned analog signal, and compares the conditioned analog signal with the negative overcurrent threshold. When the conditioned analog signal input by the second comparator U2B is greater than the negative overcurrent threshold, it outputs a low power The second comparator U2B outputs a high-level signal when the conditioned analog signal input by the second comparator U2B is less than or equal to the negative overcurrent threshold.

Referring to FIG. 4, optionally, the signal comparison circuit 1012 further includes: a third resistor R4, a fourth resistor R6, and a third capacitor C3; the first output end of the operational amplifier U1A is respectively connected with one end of the third resistor R4 and the fourth resistor One end of R6 is connected; one end of the third capacitor C3 is connected to one end of the third resistor R4, and the other end of the third capacitor C3 is connected to the other end of the fourth resistor R6 to ground. The first comparator U2A, the second comparator U2B, the third resistor R4, the fourth resistor R6, and the third capacitor C3 constitute the signal comparison circuit 1012.

FIG. 4 is a schematic circuit diagram of a signal conditioning and protection circuit 101 provided by an embodiment of the present invention. Referring to FIG. 4 , in another aspect of the embodiment of the present invention, a signal conditioning and protection circuit 101 is also provided, including: A follower circuit and a signal comparison circuit 1012; the follower circuit includes: an operational amplifier U1A; the forward input end of the operational amplifier U1A is used to receive an input signal, and the reverse input end of the operational amplifier U1A is grounded; the first output end of the operational amplifier U1A It is connected to the input end of the signal comparison circuit 1012; the second output end of the operational amplifier U1A is used to output the conditioned analog signal; the signal comparison circuit 1012 is used to output the conditioned digital signal.

The output end of the operational amplifier U1A may include: a first output end and a second output end. The first output end of the operational amplifier U1A sends the conditioned analog signal to the signal comparison circuit 1012, and the second output end sends the conditioned analog signal to the signal comparison circuit 1012. The signal is sent to the controller 102, and the signal comparator processes the conditioned analog signal and outputs the conditioned digital signal.

An exemplary explanation of the signal conditioning and protection circuit 101 follows.

As shown in Figure 4, R2, R3, C1, C2 and U1A form a follower circuit. The output signal (voltage signal) output by the current sensor 106 of the driving circuit 104 enters the non-inverting input terminal (pin 3) of the operational amplifier U1A through R2 and R3, and R2 is connected to a preset voltage, which can be 5V. A capacitor C1 is connected between R3 and the operational amplifier U1A, and the output end of the capacitor C1 is grounded, which can play the role of filtering. The inverting output terminal (pin 2) of the operational amplifier U1A is connected to the second output terminal of the operational amplifier U1A, a resistor R5 is also connected between the second output terminal and the controller 102, and a resistor R5 is also connected between the resistor R5 and the controller 102. A capacitor C4 is set, and the other end of the capacitor C4 is grounded. The forward power supply of the operational amplifier U1A is respectively connected to a preset voltage and a capacitor C2, the preset voltage can be 5V, and the other end of the capacitor is grounded. The grounding of capacitor C2 can play the role of filtering.

Optionally, the signal comparison circuit 1012 includes: a first comparator U2A, a second comparator U2B, a positive overcurrent threshold circuit 10123 and a negative overcurrent threshold circuit 10124 .

As shown in Figure 4, U2A, U2B, R4, C3, R6, R9, R10, C7, R11, R12, C8 constitute a comparator circuit, wherein R9, R10, C7 constitute a positive overcurrent threshold circuit 10123, R9 It is grounded in parallel with C7, R9 can be connected to a preset voltage, and the preset voltage can be but not limited to 5V; R11, R12, C8 constitute a negative overcurrent threshold circuit 10124, R12 and C8 are connected to ground in parallel, and R11 can be connected to a preset voltage , the preset voltage can be but not limited to 5V. The positive overcurrent threshold circuit 10123 may constitute a positive overcurrent threshold, and the negative overcurrent threshold circuit 10124 may constitute a negative overcurrent threshold.

The positive overcurrent threshold can be calculated by the following formula: R10/(R9+R10)*(the preset voltage connected with R9); the negative overcurrent threshold can be calculated by the following formula: R12/(R12+R11)*(connected with R11) preset voltage). Among them, * represents multiplication.

Continuing the above explanation of the example of the signal conditioning and protection circuit 101, as shown in FIG. 4, both the first output terminal and the second output terminal of the operational amplifier U1A output the conditioned analog signal; the first output terminal of the operational amplifier U1A A resistor R4 is respectively connected to the forward input terminal (pin 5) of the first comparator U2A and the reverse input terminal (pin 6) of the second comparator U2B, wherein R4 is connected to the first comparator U2A A capacitor C3 and a resistor R6 are also set between the forward input terminal of the first comparator U2B and the reverse input terminal of the second comparator U2B. The capacitor C3 and the resistor R6 are connected to ground in parallel, and the reverse input terminal of the first comparator U2A (the fourth tube pin) is the input pin of the negative overcurrent threshold circuit 10124, the positive input terminal (pin 7) of the second comparator U2B is the input pin of the positive overcurrent threshold circuit, when U2A and U2B receive the conditioned analog signal and Compare the positive overcurrent threshold with the negative overcurrent threshold, the conditioned analog signal is greater than the positive overcurrent threshold, and U2A outputs a low-level signal, or, when the conditioned analog signal is greater than the negative overcurrent threshold, U2B outputs a low-level signal .

The output end of the first comparator U2A is also provided with a capacitor C5 and a resistor R7, one end of the capacitor C5 is connected to the output end of the first comparator U2A, and the other end is grounded; one end of the resistor R7 is connected to the output end of the first comparator U2A , the other end of the resistor R7 is connected to a preset voltage, and the preset voltage can be but not limited to 3.3V.

The output end of the second comparator U2B is also provided with a capacitor C6 and a resistor R8. One end of the capacitor C6 is connected to the output end of the second comparator U2B, and the other end is grounded; one end of the resistor R8 is connected to the output end of the second comparator U2B, and the resistor The other end of R8 is connected to a preset voltage, and the preset voltage may be, but not limited to, 3.3V.

Optionally, the model of the operational amplifier U1A is TLV2464AQPWRQ1, the first comparator U2A and the second comparator U2B are integrated in a 2-in-1 integrated chip, and the model of the integrated chip is LM2901AVQPWRQ1. When the logic chip 103 receives the low-level signal output from at least one of U2A and U2B, the logic chip 103 can quickly cut off the output driving signal.

It should be noted that FIG. 4 also exemplifies the resistance value of each resistor and the capacity of the capacitor. The size of each resistor and capacitor in a specific circuit can be set according to practical applications, which is not limited in the present invention. Figure 4 uses a capacitor grounding in many places, which can play the role of filtering. R5, R7, and R8 keep the circuit in a stable state and play a role in stabilizing the circuit.

To sum up, the embodiments of the present invention provide a signal conditioning and protection circuit, which is simple, has clear logic, strong anti-interference, responds quickly to abnormal signals, is safe and reliable, saves electronic components, and reduces costs.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A drive control system, comprising: the device comprises a signal conditioning and protecting circuit, a controller, a logic chip, a driving circuit, a load and a current sensor;

the output end of the signal conditioning and protecting circuit is respectively connected with the controller and the logic chip; the output end of the controller is connected with the logic chip; the output end of the logic chip is connected with the driving circuit; the output end of the driving circuit is connected with the load;

the current sensor is arranged between the output end of the driving circuit and the load, is connected with the signal conditioning and protecting circuit, and is used for collecting an output signal of the driving circuit and sending the output signal of the driving circuit to the signal conditioning and protecting circuit;

the signal conditioning and protecting circuit is used for conditioning an output signal of the driving circuit, sending a conditioned digital signal to the logic chip and sending a conditioned analog signal to the controller;

the controller is used for outputting a driving signal to the logic chip according to the conditioned analog signal;

and the logic chip is used for controlling the driving circuit to drive the load according to the driving signal.

2. The system of claim 1, wherein the signal conditioning and protection circuit is specifically configured to output a low level signal to the logic chip when the output signal of the driving circuit is greater than a preset protection threshold; and when the output signal of the driving circuit is less than or equal to the preset protection threshold value, outputting a high-level signal to the logic chip.

3. The system of claim 1, wherein the signal conditioning and protection circuit comprises: follower circuit, signal comparison circuit; the follower circuit includes: an operational amplifier;

the positive input end of the operational amplifier is connected with the output end of the current sensor; the inverting input end of the operational amplifier is grounded;

the first output end of the operational amplifier is connected with the input end of the signal comparison circuit;

the second output end of the operational amplifier is connected with the input end of the controller;

and the output end of the signal comparison circuit is connected with the input end of the logic chip.

4. The system of claim 3, wherein the signal comparison circuit comprises: the overcurrent protection circuit comprises a first comparator, a second comparator, a positive overcurrent threshold circuit and a negative overcurrent threshold circuit;

the positive input end of the first comparator and the reverse input end of the second comparator are respectively connected with the first output end of the operational amplifier, the reverse input end of the first comparator is connected with the output end of the positive overcurrent threshold circuit, and the positive input end of the second comparator is connected with the output end of the negative overcurrent threshold circuit.

5. The system of claim 3, wherein the follower circuit further comprises: the circuit comprises a first resistor, a second resistor, a first capacitor and a second capacitor;

the output end of the current sensor is respectively connected with the first resistor and the second resistor, the other end of the second resistor is respectively connected with the positive input end of the operational amplifier and one end of the first capacitor, and the other end of the first capacitor is grounded;

one end of the second capacitor is connected with a positive power supply end of the operational amplifier, and a negative power supply end of the operational amplifier is connected with the ground; the other end of the second capacitor is connected to the ground.

6. The system of claim 4, wherein the signal comparison circuit further comprises: a third resistor, a fourth resistor and a third capacitor;

a first output end of the operational amplifier is respectively connected with one end of the third resistor and one end of the fourth resistor;

one end of the third capacitor is connected with one end of the third resistor, and the other end of the third capacitor is connected with the other end of the fourth resistor in a grounding mode.

7. The system of claim 1, wherein the controller is a single chip microcomputer.

8. The system of claim 1, wherein the current sensor is a hall sensor, the load is a three-phase motor, and the motor inputs a three-phase current signal; the driving circuit outputs three-phase current signals;

and the Hall sensors respectively acquire three-phase current signals output by the driving circuit.

9. A signal conditioning and protection circuit, comprising: follower circuit, signal comparison circuit; the follower circuit includes: an operational amplifier;

the forward input end of the operational amplifier is used for receiving an input signal, and the reverse input end of the operational amplifier is grounded;

the first output end of the operational amplifier is connected with the input end of the signal comparison circuit;

the second output end of the operational amplifier is used for outputting the conditioned analog signal; and the signal comparison circuit is used for outputting the conditioned digital signal.

10. The circuit of claim 9, wherein the signal comparison circuit comprises: the overcurrent protection circuit comprises a first comparator, a second comparator, a positive overcurrent threshold circuit and a negative overcurrent threshold circuit;

the positive input end of the first comparator and the reverse input end of the second comparator are respectively connected with the first output end of the operational amplifier, the reverse input end of the first comparator is connected with the output end of the positive overcurrent threshold circuit, and the positive input end of the second comparator is connected with the output end of the negative overcurrent threshold circuit.

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