Driver protection signal anti-interference circuit

Abstract

The embodiment of the invention provides a driver protection signal anti-interference circuit, and belongs to the technical field of signal circuits, the circuit comprises an RC time delay circuit which is composed of a resistor R206 and a capacitor C161 and is used for carrying out time delay processing on an input signal; the interference isolation circuit comprises a resistor R243, a resistor R205 and a diode D49; and the signal acquisition circuit consists of a pull-up resistor R205, a filter resistor R235 and a capacitor C207 and is used for acquiring and processing signals. According to the invention, the anti-interference capability of the signal is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of signal circuits, and in particular to an anti-interference circuit for driver protection signals. Background Art

[0002] In industrial production environments, there are often a large number of electrical devices running at the same time. For example, inductive loads such as motors and transformers will generate strong electromagnetic radiation during the start, stop or operation process. These electromagnetic radiations will propagate in the form of electromagnetic waves. When the signal line of the driver is within the influence range of these electromagnetic waves, additional voltage and current will be induced on the signal line, thereby interfering with the normal protection signal of the driver.

[0003] High-frequency welding equipment, induction heating equipment, etc. will generate high-frequency electromagnetic fields, which have high frequencies and strong energy, and will interfere more significantly with the driver. These high-frequency electromagnetic fields can penetrate the driver's casing and circuits, affecting the normal operation of internal electronic components.

[0004] The drive usually needs to be connected to the grid to obtain power. Voltage fluctuations in the grid, surge voltages caused by lightning strikes, and switching operations in the power system can all generate electromagnetic interference. For example, when a large load in the grid is suddenly cut off, a voltage surge will occur, which may cause overvoltage in the drive; and the surge voltage caused by lightning strikes can reach thousands of volts or even higher, causing direct damage to the electronic components of the drive.

[0005] The operating environment of the drive is relatively harsh, and its protection signals such as current signals, over-voltage and under-voltage signals, and temperature signals are more easily interfered with, which can cause the drive to malfunction, and in severe cases, safety accidents may occur.

[0006] The above problems become technical problems that need to be solved. Summary of the invention

[0007] In view of this, an embodiment of the present invention provides a driver protection signal anti-interference circuit, which at least partially solves the problems existing in the prior art.

[0008] An embodiment of the present invention provides a driver protection signal anti-interference circuit, comprising:

[0009] The RC delay circuit is composed of a resistor R206 and a capacitor C161. The delay time T is calculated according to the formula T = R × C, where R is the resistance value and C is the capacitance value. It is used to delay the input signal.

[0010] The interference isolation circuit includes resistors R243, R205 and a diode D49. The diode has unidirectional conductivity. Under normal circumstances, the potential of point A is equal to the potential of point B and equal to the potential of OC_FLT. When the OC_FLT signal is interfered with and becomes a high-level pulse, the potentials of point A and point B are equal, so that FO maintains a high level without interference. Under abnormal circumstances, when the protection signal OC_FLT is pulled low, the potential of point A is pulled low through the diode D49, so that FO is pulled low to trigger software or hardware protection.

[0011] The signal acquisition circuit is composed of a pull-up resistor R205, a filter resistor R235 and a capacitor C207, and is used to collect and process signals, wherein the OC_FLT signal is a processed signal of one or more of a current signal, an over-voltage or under-voltage signal or a temperature signal.

[0012] According to a specific implementation of the embodiment of the present invention, the resistance value of the resistor R206 is 100R, the capacitance value of the capacitor C161 is 471F, and the delay time calculated by the formula T=R×C is 47100 seconds.

[0013] According to a specific implementation of the embodiment of the present invention, the resistance value of the resistor R243 in the interference isolation circuit is 5.1K, the resistance value of R205 is 5.1K, and the resistance ratio thereof is 1:1.

[0014] According to a specific implementation of the embodiment of the present invention, the diode D49 is a BAW56LT1G diode.

[0015] According to a specific implementation of the embodiment of the present invention, the resistance of the filter resistor R235 in the signal acquisition circuit is 1K, which is used to perform a certain degree of filtering on the acquired signal to remove interference signals in a specific frequency range.

[0016] According to a specific implementation of the embodiment of the present invention, the capacitance value of the capacitor C207 is 102F, and the capacitor C207 cooperates with the filter resistor R235 to generate a cutoff frequency for filtering out interference signals higher than the cutoff frequency.

[0017] According to a specific implementation of the embodiment of the present invention, a shielding shell is also included, and the shielding shell is used to shield the entire anti-interference circuit.

[0018] According to a specific implementation of the embodiment of the present invention, an electrostatic protection device is provided at the interface where the signal acquisition circuit is connected to an external device, so as to prevent electrostatic discharge from damaging the signal acquisition circuit.

[0019] According to a specific implementation of an embodiment of the present invention, the connection lines between the RC delay circuit, the interference isolation circuit and the signal acquisition circuit are isolated by using a signal shielding device to reduce signal interference during line transmission.

[0020] According to a specific implementation of an embodiment of the present invention, the interference isolation circuit further includes a voltage regulator diode connected in parallel with the diode D49, which is used to limit the pull-down amplitude of the potential at point A under abnormal conditions, and the voltage regulator diode has a preset voltage regulation value.

[0021] The solution of the present invention has the following beneficial effects:

[0022] 1. Strong anti-interference ability

[0023] The input protection signal is delayed through the RC delay circuit. This helps to filter out instantaneous interference and noise in the signal. The interference isolation circuit uses the unidirectional conduction characteristics of the diode to effectively isolate external interference under normal circumstances. When the OC_FLT signal is interfered with, the circuit can ensure the normal operation of the system. The signal acquisition circuit also uses a similar delay filtering principle to further process the signal. Through the synergistic effect of the pull-up resistor, filter resistor and capacitor, the collected protection signal is more accurate, reducing the misjudgment caused by signal distortion.

[0024] 2. Prevent malfunction

[0025] The malfunction of the driver is often caused by the interference of the protection signal. This anti-interference design can accurately distinguish the real protection signal from the interference signal. For example, in terms of temperature signals, when the driver is in the normal operating temperature range, but the temperature sensor signal fluctuates abnormally due to external electromagnetic interference, the circuit can filter out such abnormal fluctuations, avoiding the driver from erroneously starting the protection mechanism due to misjudgment of too high or too low temperature, such as unnecessary shutdown or frequency reduction operation, thus ensuring the continuous and stable operation of the driver under normal working conditions.

[0026] 3. Trigger protection in time

[0027] In abnormal situations, such as when the protection signal OC_FLT is pulled low, the interference isolation circuit can respond quickly, pulling down the potential of the relevant signal point through the diode, thereby triggering the software or hardware protection mechanism. This ensures that when dangerous situations such as overcurrent, over-voltage, undervoltage, and overtemperature actually occur, the driver can be protected in time to avoid equipment damage or even safety accidents caused by untimely protection.

[0028] 4. Adjustable delay time

[0029] The delay time of the RC delay circuit and the signal acquisition circuit can be flexibly set by adjusting the values ​​of the resistor and capacitor. This allows the circuit to adapt to different application scenarios and different types of drivers. For example, for some drivers that require high signal response speed, the delay time can be appropriately reduced; and for drivers working in an environment with severe electromagnetic interference, the delay time can be increased by increasing the capacitor and resistor values ​​to improve the anti-interference ability. This flexibility makes the circuit have a wide range of application potential in a variety of industrial and electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of an interference isolation circuit provided by an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of an RC delay circuit provided by an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of a signal acquisition circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0036] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein may be implemented independently of any other aspect, and two or more of these aspects may be combined in various ways. For example, any number of aspects described herein may be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein may be used to implement this device and / or practice this method.

[0037] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The drawings only show components related to the present disclosure rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0038] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0039] See also Figure 1 , Figure 2 and Figure 3 , the embodiment of the present disclosure provides a driver protection signal anti-interference circuit, comprising:

[0040] The RC delay circuit is composed of a resistor R206 and a capacitor C161. The delay time T is calculated according to the formula T = R × C, where R is the resistance value and C is the capacitance value. It is used to delay the input signal.

[0041] The interference isolation circuit includes resistors R243, R205 and a diode D49. The diode has unidirectional conductivity. Under normal circumstances, the potential of point A is equal to the potential of point B and equal to the potential of OC_FLT. When the OC_FLT signal is interfered with and becomes a high-level pulse, the potentials of point A and point B are equal, so that FO maintains a high level without interference. Under abnormal circumstances, when the protection signal OC_FLT is pulled low, the potential of point A is pulled low through the diode D49, so that FO is pulled low to trigger software or hardware protection.

[0042] The signal acquisition circuit is composed of a pull-up resistor R205, a filter resistor R235 and a capacitor C207, and is used to collect and process signals, wherein the OC_FLT signal is a processed signal of one or more of a current signal, an over-voltage or under-voltage signal or a temperature signal.

[0043] The RC delay circuit is realized by RC filtering composed of R206 and C161. The delay time can be calculated according to the following formula:

[0044] T=R×C

[0045] Among them, T represents the delay time, R represents the resistance value, and C represents the capacitance value.

[0046] The interference isolation circuit is mainly realized through the unidirectional conductivity of the diode. The principle is as follows:

[0047] Under normal circumstances, due to the existence of R243 and 205 resistors, the potential of point A is equal to the potential of point B, that is, the potential of OC_FLT is equal to the potential of A; when the OC_FLT signal is interfered, the interference signal is superimposed on point B and is also a high-level pulse signal, which is equal to the level of point A, so FO is still high and is not affected by the interference signal, and the system operates normally;

[0048] Under abnormal circumstances: the protection signal OC_FLT is pulled low → point B is pulled low → the potential of point A is pulled low through the D49 diode → FO is pulled low to trigger software or hardware protection, and then the system is protected.

[0049] The OC_FLT signal may be a processed current signal, an over-voltage or under-voltage signal, a temperature signal, etc.

[0050] Signal acquisition circuit This circuit is mainly realized by pull-up resistor R205, filter resistor R235 and C207. The principle is as follows:

[0051] The delay time can be calculated according to the following formula:

[0052] T=R×C

[0053] Among them, T represents the delay time, R represents the resistance value, and C represents the capacitance value.

[0054] According to a specific implementation of the embodiment of the present invention, the resistance value of the resistor R206 is 100R, the capacitance value of the capacitor C161 is 471F, and the delay time calculated by the formula T=R×C is 47100 seconds.

[0055] According to a specific implementation of the embodiment of the present invention, the resistance value of the resistor R243 in the interference isolation circuit is 5.1K, the resistance value of R205 is 5.1K, and the resistance ratio thereof is 1:1.

[0056] According to a specific implementation of the embodiment of the present invention, the diode D49 is a BAW56LT1G diode.

[0057] According to a specific implementation of the embodiment of the present invention, the resistance of the filter resistor R235 in the signal acquisition circuit is 1K, which is used to perform a certain degree of filtering on the acquired signal to remove interference signals in a specific frequency range.

[0058] According to a specific implementation of the embodiment of the present invention, the capacitance value of the capacitor C207 is 102F, and the capacitor C207 cooperates with the filter resistor R235 to generate a cutoff frequency for filtering out interference signals higher than the cutoff frequency.

[0059] According to a specific implementation of the embodiment of the present invention, a shielding shell is also included, and the shielding shell is used to shield the entire anti-interference circuit.

[0060] According to a specific implementation of the embodiment of the present invention, an electrostatic protection device is provided at the interface where the signal acquisition circuit is connected to an external device, so as to prevent electrostatic discharge from damaging the signal acquisition circuit.

[0061] According to a specific implementation of an embodiment of the present invention, the connection lines between the RC delay circuit, the interference isolation circuit and the signal acquisition circuit are isolated by using a signal shielding device to reduce signal interference during line transmission.

[0062] According to a specific implementation of an embodiment of the present invention, the interference isolation circuit further includes a voltage regulator diode connected in parallel with the diode D49, which is used to limit the pull-down amplitude of the potential at point A under abnormal conditions, and the voltage regulator diode has a preset voltage regulation value.

[0063] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A driver protection signal anti-interference circuit, characterized in that: include: The RC delay circuit is composed of a resistor R206 and a capacitor C161. The delay time T is calculated according to the formula T = R × C, where R is the resistance value and C is the capacitance value. It is used to delay the input signal. The interference isolation circuit includes resistors R243, R205 and a diode D49. The diode has unidirectional conductivity. Under normal circumstances, the potential of point A is equal to the potential of point B and equal to the potential of OC_FLT. When the OC_FLT signal is interfered with and becomes a high-level pulse, the potentials of point A and point B are equal, so that FO maintains a high level without interference. Under abnormal circumstances, when the protection signal OC_FLT is pulled low, the potential of point A is pulled low through the diode D49, so that FO is pulled low to trigger software or hardware protection. The signal acquisition circuit is composed of a pull-up resistor R205, a filter resistor R235 and a capacitor C207, and is used to collect and process signals, wherein the OC_FLT signal is a processed signal of one or more of a current signal, an over-voltage or under-voltage signal or a temperature signal.

2. The driver protection signal anti-interference circuit according to claim 1, characterized in that: The resistance value of the resistor R206 is 100R, the capacitance value of the capacitor C161 is 471F, and the delay time calculated by the formula T=R×C is 47100 seconds.

3. The driver protection signal anti-interference circuit according to claim 2, characterized in that: The resistance value of the resistor R243 in the interference isolation circuit is 5.1K, and the resistance value of the resistor R205 is 5.1K, and the resistance ratio thereof is 1:

1.

4. The driver protection signal anti-interference circuit according to claim 3, characterized in that: The diode D49 is a BAW56LT1G diode.

5. The driver protection signal anti-interference circuit according to claim 4, characterized in that: The resistance value of the filter resistor R235 in the signal acquisition circuit is 1K, and is used to perform a certain degree of filtering on the collected signal to remove interference signals in a specific frequency range.

6. The driver protection signal anti-interference circuit according to claim 5, characterized in that: The capacitance value of the capacitor C207 is 102F. The capacitor C207 cooperates with the filter resistor R235 to generate a cutoff frequency for filtering out interference signals higher than the cutoff frequency.

7. The driver protection signal anti-interference circuit according to claim 6, characterized in that: The invention also comprises a shielding shell, which is used for shielding the entire anti-interference circuit.

8. The driver protection signal anti-interference circuit according to claim 7, characterized in that: An electrostatic protection device is provided at the interface where the signal acquisition circuit is connected to the external device, so as to prevent electrostatic discharge from damaging the signal acquisition circuit.

9. The driver protection signal anti-interference circuit according to claim 8, characterized in that: The connection lines between the RC delay circuit, the interference isolation circuit and the signal acquisition circuit are isolated by using signal shielding devices to reduce signal interference during line transmission.

10. The driver protection signal anti-interference circuit according to claim 9, characterized in that: The interference isolation circuit further includes a voltage regulator diode connected in parallel with the diode D49, which is used to limit the pull-down amplitude of the potential at point A under abnormal conditions. The voltage regulator diode has a preset voltage regulation value.

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