Filter circuit of encoder

Abstract

The utility model discloses a filter circuit of an encoder. The filter circuit comprises a driver. The filter comprises a voltage input end, a voltage output end, at least one inductor and a plurality of capacitors; the voltage input end is electrically connected with the driver; each capacitor is electrically connected with the adjacent capacitor, the previous capacitor is electrically connected with the voltage input end, and the next capacitor is electrically connected with the voltage output end; the inductor is arranged at a circuit connection point between two capacitors; and the encoder is electrically connected with the voltage output end. When the voltage input end of the driver outputs, the effects of filtering and smoothing the output voltage are achieved under the filtering effect of the front part of capacitors, high-frequency noise and harmonic waves are filtered out through the inductor to be used for improving the stability and the anti-jamming capability of the circuit and guaranteeing the stability of the power supply voltage of the encoder, and the remaining high-frequency noise is further filtered out through the rear capacitor. The stability of voltage output to the voltage output end is ensured, and it is ensured that the encoder can accurately detect the position and speed information of the motor.

Description

Technical Field

[0001] The utility model relates to the technical field of motor circuits, in particular to a filter circuit of an encoder. Background Art

[0002] The incremental encoder is suitable for the closed-loop vector control system of permanent magnet synchronous motors and is often used in servo drives. The incremental encoder outputs phase pulse signals, so the incremental encoder requires a power supply powered by the driver output voltage.

[0003] In some usage scenarios, such as when the drive and the permanent magnet synchronous motor encoder are connected over a long distance, typically 5 to 10 meters, a cable that is too long or too thin can cause excessive impedance in the voltage supply line and fluctuations, affecting the encoder's stability and causing inaccurate pulse signal counts, impacting transmission accuracy. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art solutions, an embodiment of the present utility model provides a filter circuit for an encoder.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A filter circuit for an encoder, the filter circuit comprising:

[0007] Driver;

[0008] A filter comprising a voltage input terminal, a voltage output terminal, at least one inductor, and a plurality of capacitors; the voltage input terminal is electrically connected to the driver; each capacitor is electrically connected to an adjacent capacitor, wherein the first capacitor is electrically connected to the voltage input terminal, and the second capacitor is electrically connected to the voltage output terminal; the inductor is disposed at a circuit connection point between two of the capacitors;

[0009] An encoder is electrically connected to the voltage output end.

[0010] As a preferred technical solution of the present invention, the multiple capacitors include a first capacitor, a second capacitor and a third capacitor; the first capacitor is electrically connected to the voltage input end, the third capacitor is electrically connected to the voltage output end, the second capacitor is arranged at a circuit connection point between the first capacitor and the second capacitor; the inductor is arranged at a circuit connection point between the first capacitor and the second capacitor.

[0011] As a preferred technical solution of the present invention, both the first capacitor and the second capacitor are polarized capacitors.

[0012] As a preferred technical solution of the present invention, the first capacitor, the second capacitor and the third capacitor are all connected to the ground line.

[0013] As a preferred technical solution of the present invention, the forward pulse end and the reverse pulse end of the driver are respectively connected to the input end of the encoder.

[0014] As a preferred technical solution of the present invention, the multiple positive feedback pulse ends of the driver are respectively connected to the multiple positive output ends of the encoder, and the multiple negative feedback pulse ends of the driver are respectively connected to the multiple negative output ends of the encoder.

[0015] As a preferred technical solution of the present invention, the filter circuit further includes a first connector, the voltage input end is connected to the first connector, and the first connector is grounded.

[0016] As a preferred technical solution of the present invention, the filter circuit further includes a second connector, the voltage output end is connected to the second connector, and the second connector is grounded.

[0017] As a preferred technical solution of the present invention, the multiple alarm signal terminals of the driver are respectively connected to the status output terminals of the encoder.

[0018] As a preferred technical solution of the present invention, the filtering circuit further includes a position generator, the encoder is electrically connected to the position generator, and the position generator is electrically connected to the main shaft of the motor.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] When the driver voltage input terminal outputs, the first part of the capacitor filters and smoothes the output voltage, and the inductor filters out high-frequency noise and harmonics to improve the stability and anti-interference ability of the circuit and ensure the stability of the encoder supply voltage. The latter capacitor further filters out the remaining high-frequency noise to ensure the stability of the output voltage to the voltage output terminal and ensure that the encoder can accurately detect the position and speed information of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1This is a wiring diagram of the driver and encoder of an embodiment of the utility model.

[0023] Figure 2 It is a wiring diagram of the filter according to an embodiment of the present utility model.

[0024] Figure 3 This is a wiring diagram of the first connector according to an embodiment of the present utility model.

[0025] Figure 4 This is a wiring diagram of the second connector according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clear, this application is further described in detail below with reference to the accompanying drawings and embodiments.

[0027] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0028] It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it can be directly on the other element or indirectly on the other element.

[0029] When an element is referred to as being “connected to” another element, it can be directly connected to the another element or indirectly connected to the another element.

[0030] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0032] In the description of the present application, “plurality” means two or more, unless otherwise clearly defined.

[0033] In order to solve the technical problems in the prior art that the connecting wires are too long or too thin, which will cause the power supply line impedance to be too large and fluctuate, affecting the stability of the encoder, and at the same time causing inaccurate number of pulse signals and affecting transmission accuracy, the embodiment of the present invention provides a filter circuit for the encoder.

[0034] The following describes in detail a specific embodiment of a filter circuit for an encoder according to the embodiment of the present invention. Figure 1-4 As shown in , the filtering circuit specifically includes a driver, a filter and an encoder.

[0035] The driver receives the encoder's output signal and filters it. This filtering process removes noise and interference from the signal, making it clearer and more stable, enabling accurate decoding and acquisition of information such as position or speed. The driver's internal filter circuit converts the encoder's pulse signal into an accurate and reliable digital signal, providing accurate position or speed feedback data for the subsequent control system. Finally, the filtered signal enters the voltage stabilization circuit, which provides a stable output voltage for the driver. This voltage stabilization circuit can be implemented using a voltage regulator or switching regulator. Furthermore, the driver can provide other functions such as gain adjustment and pulse shaping to improve system performance and stability.

[0036] It is understood that the embodiments of the present invention are DC or AC drives. For example, a DC drive can provide stable current and voltage outputs and is suitable for applications requiring precise control of signal strength. Therefore, it is used in incremental encoder filter circuits to ensure signal stability and reliability. The specific type of drive is not limited here.

[0037] according to Figure 2 As shown, the filter includes a voltage input terminal VCC, a voltage output terminal VCC1, at least one inductor L1, and multiple capacitors; the voltage input terminal VCC is electrically connected to the driver; each capacitor is electrically connected to the adjacent capacitor, wherein the first capacitor is electrically connected to the voltage input terminal VCC, and the second capacitor is electrically connected to the voltage output terminal VCC1; the inductor L1 is arranged at a circuit connection point between two capacitors;

[0038] Specifically, in order to stabilize the encoder, the connecting line is too long, resulting in excessive impedance of the power supply line, which causes signal fluctuations. Therefore, before a certain voltage is output to the encoder through the driver, it must pass through the filter of this embodiment. The filter includes an inductor L1 and multiple capacitors. Specifically, the inductor L1 has an impedance effect on the AC signal, and the multiple capacitors store and release charges. According to this arrangement, when the voltage passes through the filter, the inductor L1 prevents the passage of high-frequency components, while the capacitors can smooth the low-frequency components. This combination is used to effectively filter out high-frequency noise and interference in the power supply.

[0039] according to Figure 2 As shown, in some specific embodiments, the multiple capacitors include a first capacitor C1, a second capacitor C2 and a third capacitor C3; the first capacitor C1 is electrically connected to the voltage input terminal VCC, the third capacitor C3 is electrically connected to the voltage output terminal VCC1, and the second capacitor C2 is arranged at a circuit connection point between the first capacitor C1 and the second capacitor C2; the inductor L1 is arranged at a circuit connection point between the first capacitor C1 and the second capacitor C2.

[0040] More specifically, the first and second capacitors C1 and C2 are connected in parallel between the voltage input terminal VCC and the ground line, providing a filter that absorbs AC components and high-frequency noise in the power line, thereby maintaining a stable output voltage. Inductor L1 can be understood as a magnetic circuit, with its two ends connected between two adjacent capacitors. This increases the impedance of inductor L1, thereby suppressing high-frequency noise and voltage spikes in the power line. The third capacitor C3 further filters out high-frequency noise, forming a low-pass filter with the two aforementioned capacitors, allowing the AC component in the power line to transition smoothly to DC.

[0041] With the above arrangement, for example, when the driver outputs a +5V voltage input terminal VCC, the AC component and high-frequency noise in the power line are weakened by the filtering effect of the first capacitor C1 and the second capacitor C2. At the same time, the inductor L1 generates impedance to the high-frequency component in the power line, thereby suppressing it. Subsequently, the AC component in the power line is greatly reduced, and most of it is converted into a DC component. The last capacitor further filters out the remaining high-frequency noise, ensuring the stability of the voltage output to the voltage output terminal VCC1.

[0042] The encoder is electrically connected to the voltage output terminal VCC1.

[0043] Specifically, since the voltage output from the voltage output terminal VCC1 is filtered to eliminate high-frequency interference and harmonic components in the power supply, the filtered voltage is provided to the encoder, and the circuit board and electronic components inside the encoder receive the voltage and convert it into the signal required for the normal operation of the encoder.

[0044] In a further embodiment, the first capacitor C1 and the second capacitor C2 are both polarized capacitors.

[0045] Specifically, in this circuit, the first capacitor C1 and the second capacitor C2 are polarized capacitors. Since polarized capacitors have basic capacitance-impedance characteristics and good decoupling capabilities, they can store a large amount of charge in a short period of time. When the power signal is connected to the polarized capacitor, the two plates of the capacitor store positive and negative charges respectively, forming a charge pile. When the power signal is disconnected, the charge in the charge pile can be slowly released through the internal structure of the capacitor, thereby providing a stable DC voltage; therefore, in actual use, electrolytic capacitors can store charge more stably and power the power supply equipment, maintaining voltage stability throughout the power supply sequence.

[0046] according to Figure 2 As shown, in a further embodiment, the first capacitor C1 , the second capacitor C2 and the third capacitor C3 are all connected to the ground.

[0047] Specifically, by grounding the first capacitor C1, the second capacitor C2, and the third capacitor C3, a stable reference potential is provided, so that the signals in the circuit can be stably transmitted and processed, and the electromagnetic interference and noise in the circuit can be effectively reduced, thereby improving the performance of the circuit. It can also protect electrical equipment from dangers such as electric shock and electrostatic discharge, thereby ensuring the safe operation of the motor.

[0048] according to Figure 1 As shown, in some specific embodiments, the forward pulse terminal and the reverse pulse terminal of the driver are respectively connected to the input terminal of the encoder.

[0049] Specifically, the driver's forward pulse terminals, CCW+ and CCW-, represent the positive and negative terminals of the motor's clockwise rotation signal. The encoder's input terminals, A+ / P+ and A- / P-, output the positive and negative terminals of the rotation direction signal. When the motor rotates clockwise, the encoder generates a corresponding pulse signal. The driver detects the motor's rotation direction by monitoring these two signals, ensuring that the driver receives the correct direction signal when the motor rotates counterclockwise. The driver's reverse pulse terminals, CW+ and CW-, represent the positive and negative terminals of the motor's counterclockwise rotation signal. The specific principles are similar to those of the forward pulse terminals and will not be elaborated on here.

[0050] More specifically, the driver outputs a PWM (pulse width modulation) signal or direction signal through the forward and reverse pulse terminals, thereby controlling the motor's rotation direction. When the driver requires the motor to rotate counterclockwise, it outputs a signal through the forward pulse terminal; when the motor needs to rotate clockwise, it outputs a signal through the reverse pulse terminal. This signal, after undergoing appropriate current drive and level conversion, is transmitted to the input terminal of the motor encoder. Simultaneously, the encoder outputs a two-phase sinusoidal signal with a 90-degree phase difference through input terminals A+ / A- and B+ / B-. This signal represents the motor's rotation direction and position information. The encoder's internal sensor detects the motor's rotation and feeds this information back to the driver through input terminals A+ and B+. Finally, after receiving the encoder's feedback signal, the driver can accurately obtain information such as the motor's position, speed, and direction, thereby achieving precise control.

[0051] according to Figure 1 As shown, in some specific embodiments, multiple positive feedback pulse terminals of the driver are respectively connected to multiple positive output terminals of the encoder, and multiple negative feedback pulse terminals of the driver are respectively connected to multiple negative output terminals of the encoder.

[0052] Specifically, the positive feedback pulse terminals of the driver include A+, B+, and Z+, and the negative feedback pulse terminals include A-, B-, and Z-. The multiple positive output terminals of the encoder include OA+, OB+, and OZ+, and the multiple negative output terminals include OA-, OB-, and OZ-. Therefore, the positive feedback pulse terminal A+ of the driver is connected to the positive output terminal OA+ of the encoder, and the positive feedback pulse terminal B+ of the driver is connected to the positive output terminal OB+ of the encoder, and so on. For example, when the two pairs of differential signals (OA+ / OA- and OB+ / OB-) output by the encoder represent phase A and phase B, it can be understood that the phase difference between the two is 90 degrees, which is used to detect the rotation direction and position of the motor. By analyzing the phase relationship of the two pairs of differential signals, the driver can determine the rotation direction of the motor and determine the speed and position of the motor by counting pulses. The driver's feedback pulse terminals A+ / A- and B+ / B- are used to receive differential signals, which can amplify the voltage difference between the two signal lines and suppress common-mode noise. This connection method can effectively improve the reliability and accuracy of the motor control system, especially in environments with electromagnetic interference.

[0053] according to Figure 3-4 As shown, in some specific embodiments, the filter circuit further includes a first connector CN1, the voltage input terminal VCC is connected to the first connector CN1, and the ground line is connected to the first connector CN1. The filter circuit further includes a second connector CN2, the voltage output terminal VCC1 is connected to the second connector CN2, and the ground line is connected to the second connector CN2.

[0054] Specifically, when the voltage input terminal VCC is connected to the ground line through the first connector CN1, and the voltage output terminal VCC1 is connected to the ground line through the second connector CN2, current can be transmitted from the positive terminal of the power supply through the connector to the negative terminal or ground line, forming a circuit loop. The first connector CN1 and the second connector CN2 typically have contact points or pins made of conductive material to achieve electrical connection between the circuits. Each connector has good insulation properties to prevent short circuits or interference between different circuits. In addition, each connector also has a shielding function, which can reduce the impact of electromagnetic interference (EMI) on the circuit and improve the circuit's anti-interference ability.

[0055] according to Figure 1 As shown, in some specific embodiments, multiple alarm signal terminals of the driver are respectively connected to the status output terminals of the encoder.

[0056] Specifically, the driver includes two alarm signal terminals (ALARM), and the status output terminals of the encoder include TA and TB / TC. When the driver detects an abnormal situation, an alarm signal is sent through the alarm signal terminal. The alarm signal terminal is a digital output used to indicate whether the driver is in a normal state or whether a fault is detected. When the driver receives the signal, it usually takes corresponding measures to respond to the fault, including stopping the motor operation, switching to a safe mode, or triggering an external alarm system. With this setting, the system can protect itself and other equipment from damage when a fault occurs.

[0057] For example, if the status output terminal of the encoder sends out an abnormal signal, such as signal jitter, frequent and irregular signal fluctuations, it may indicate an encoder failure or connection problem, or the signal loses synchronization, and the A / B phase relationship is abnormal, which may indicate an internal fault of the encoder. At this time, after the driver receives the signal sent by the alarm signal terminal, it takes corresponding measures according to the configuration, such as stopping the motor operation, issuing an alarm signal, etc., thereby realizing real-time monitoring and protection of motor abnormal conditions.

[0058] according to Figure 1 As shown, in some specific embodiments, the filter circuit further includes a position generator PG, the encoder is electrically connected to the position generator PG, and the position generator PG is electrically connected to the main shaft of the motor.

[0059] Specifically, the position generator PG is a pulse signal output by the encoder, which is used to provide the motor's speed and position information to the driver. The frequency and amplitude of the signal output by the position generator PG are usually proportional to the motor's speed. Therefore, the motor's speed and position are calculated by measuring the frequency or amplitude of the signal output by the position generator PG. After detecting changes in the signal output by the position generator PG, corresponding control operations can be performed, such as adjusting the motor's spindle speed, stopping the motor's spindle operation, etc.

[0060] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A filter circuit for an encoder, characterized in that: The filtering circuit comprises: Driver; A filter comprising a voltage input terminal, a voltage output terminal, at least one inductor, and a plurality of capacitors; the voltage input terminal is electrically connected to the driver; each capacitor is electrically connected to an adjacent capacitor, wherein the first capacitor is electrically connected to the voltage input terminal, and the second capacitor is electrically connected to the voltage output terminal; the inductor is disposed at a circuit connection point between two of the capacitors; An encoder is electrically connected to the voltage output end.

2. The filter circuit of the encoder according to claim 1, characterized in that The plurality of capacitors include a first capacitor, a second capacitor, and a third capacitor; the first capacitor is electrically connected to the voltage input terminal, the third capacitor is electrically connected to the voltage output terminal, the second capacitor is arranged at a circuit connection point between the first capacitor and the second capacitor; and the inductor is arranged at a circuit connection point between the first capacitor and the second capacitor.

3. The filter circuit of the encoder according to claim 2, characterized in that: The first capacitor and the second capacitor are both polarized capacitors.

4. The filter circuit of the encoder according to any one of claims 2 or 3, characterized in that: The first capacitor, the second capacitor and the third capacitor are all connected to the ground line.

5. The filter circuit of the encoder according to claim 1, characterized in that: The forward pulse terminal and the reverse pulse terminal of the driver are respectively connected to the input terminal of the encoder.

6. The filter circuit of the encoder according to claim 1, characterized in that: The multiple positive feedback pulse terminals of the driver are respectively connected to the multiple positive output terminals of the encoder, and the multiple negative feedback pulse terminals of the driver are respectively connected to the multiple negative output terminals of the encoder.

7. The filter circuit of the encoder according to claim 1, characterized in that: The filter circuit further includes a first connector, the voltage input end is connected to the first connector, and the first connector is grounded.

8. The filter circuit of the encoder according to claim 1, characterized in that: The filter circuit further includes a second connector, the voltage output end is connected to the second connector, and the second connector is grounded.

9. The filter circuit of the encoder according to claim 1, characterized in that: The multiple alarm signal terminals of the driver are respectively connected to the status output terminals of the encoder.

10. The filter circuit of the encoder according to claim 1, characterized in that: The filtering circuit further includes a position generator, the encoder is electrically connected to the position generator, and the position generator is electrically connected to the main shaft of the motor.

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