Rotary encoder excitation amplification circuit on industrial servo driver

Abstract

The utility model discloses a rotary encoder excitation amplification circuit on an industrial servo driver. The rotary encoder excitation amplification circuit comprises a power supply module, a communication module and a filtering module. The power supply module is connected with the communication module and the filtering module, and the communication module is connected with the filtering module. The size of an excitation output signal is adjusted through the RS8471YTDC8 operational amplifier and the resistor, the signal is reduced through the filter capacitor and the operational amplifier, and the RS8471YTDC8 operational amplifier ensures rapid establishment and low distortion of a high-frequency excitation signal, reduces signal distortion and noise interference, improves reliability and safety, and protects an encoder circuit from being damaged. The circuit is simple, few in used components, low in cost, low in power consumption of components selected by the circuit, faster in signal transmission, and capable of reducing distortion, prolonging the service life of the servo frequency converter and improving the safety and the reliability of the servo frequency converter.

Description

Technical Field

[0001] This utility model belongs to the field of amplifier circuit technology, and relates to a rotary encoder excitation amplifier circuit for an industrial servo driver. Background Technology

[0002] In the field of industrial drives, the excitation amplifier circuit of a rotary encoder is a core component that ensures accurate position and speed detection. Currently, the mainstream topologies are discrete transistor push-pull amplifier circuits and integrated operational amplifier circuits. Among these, the discrete transistor push-pull amplifier circuit is widely used due to its simple structure, but its high static power consumption and significant heat generation are prominent drawbacks: during continuous operation, the high power consumption is converted into heat, which not only reduces circuit efficiency but also affects component performance stability due to high temperatures, shortening equipment lifespan. In long-term, high-load industrial scenarios, the heat dissipation pressure further exacerbates system reliability risks. While conventional integrated dual operational amplifier circuits simplify design, they are limited by insufficient load capacity: when signals need to be transmitted over long distances, problems such as signal distortion and attenuation easily occur, leading to a decrease in the accuracy of the encoder's position and speed feedback signals, making it difficult to meet the stringent requirements of industrial automation for high precision and high anti-interference capabilities. Summary of the Invention

[0003] To address the problems existing in the background technology, this utility model proposes a rotary encoder excitation amplifier circuit for an industrial servo drive.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a rotary encoder excitation amplification circuit on an industrial servo driver, comprising: a power supply module, a communication module, and a filtering module;

[0005] The power supply module is connected to the communication module and the filter module, and the communication module is connected to the filter module.

[0006] The power module includes: capacitor C10 and capacitor C11;

[0007] The input power supply PG12V is connected to one end of capacitor C10 and one end of capacitor C11, and the other ends of capacitor C10 and capacitor C11 are connected to ground.

[0008] The communication module includes: operational amplifier U1, operational amplifier U2, resistor R5, resistor R2, capacitor C1, resistor R10, resistor R13, and capacitor C7;

[0009] One end of resistor R5 is connected to the -IN pin of operational amplifier U1, one end of resistor R2, and one end of capacitor C1. The other end of capacitor C1 is connected to the other end of resistor R2 and the OUT pin of operational amplifier U1. The input power supply PG12V is connected to the +Vs pin of operational amplifier U1, and the -Vs pin of operational amplifier U1 is connected to ground.

[0010] One end of resistor R10 is connected to the -IN pin of operational amplifier U2, one end of resistor R13, and one end of capacitor C7. The other end of capacitor C7 is connected to the other end of resistor R13 and the OUT pin of operational amplifier U2. The input power supply PG12V is connected to the +Vs pin of operational amplifier U2, and the -Vs pin of operational amplifier U2 is connected to ground.

[0011] The filter module includes: capacitor C5, resistor R7, and resistor R8;

[0012] One end of capacitor C5 is connected to one end of resistor R7, one end of resistor R8, the +IN pin of operational amplifier U1, and the IN pin of operational amplifier U2. The other end of capacitor C5 is connected to the other end of resistor R7 and ground. The other end of resistor R8 is connected to the input power supply PG12V.

[0013] Furthermore,

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This circuit uses an RS8471YTDC8 operational amplifier and resistors to adjust the magnitude of the excitation output signal. By using a filter capacitor and operational amplifier to reduce signal intensity, and leveraging the RS8471YTDC8 operational amplifier to ensure rapid establishment and low distortion of the high-frequency excitation signal, it reduces signal distortion and noise interference, improving reliability and safety, and protecting the encoder circuit from damage. This circuit is simple, uses few components, has low cost, and employs low-power components, resulting in faster signal transmission, reduced distortion, extended lifespan of the servo inverter, and improved safety and reliability. Attached Figure Description

[0016] Figure 1 This is a block diagram of a rotary encoder excitation amplifier circuit on an industrial servo driver according to this utility model;

[0017] Figure 2 This is a connection diagram of a rotary encoder excitation amplifier circuit on an industrial servo driver according to this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] like Figures 1-2 As shown, the technical solution adopted by this utility model is as follows: a rotary encoder excitation amplifier circuit on an industrial servo driver, comprising: a power supply module, a communication module, and a filtering module;

[0020] The power supply module is connected to the communication module and the filter module, and the communication module is connected to the filter module.

[0021] The power module includes: capacitor C10 and capacitor C11;

[0022] The input power supply PG12V is connected to one end of capacitor C10 and one end of capacitor C11, and the other ends of capacitor C10 and capacitor C11 are connected to ground.

[0023] The communication module includes: operational amplifier U1, operational amplifier U2, resistor R5, resistor R2, capacitor C1, resistor R10, resistor R13, and capacitor C7;

[0024] One end of resistor R5 is connected to the -IN pin of operational amplifier U1, one end of resistor R2, and one end of capacitor C1. The other end of capacitor C1 is connected to the other end of resistor R2 and the OUT pin of operational amplifier U1. The input power supply PG12V is connected to the +Vs pin of operational amplifier U1, and the -Vs pin of operational amplifier U1 is connected to ground.

[0025] One end of resistor R10 is connected to the -IN pin of operational amplifier U2, one end of resistor R13, and one end of capacitor C7. The other end of capacitor C7 is connected to the other end of resistor R13 and the OUT pin of operational amplifier U2. The input power supply PG12V is connected to the +Vs pin of operational amplifier U2, and the -Vs pin of operational amplifier U2 is connected to ground.

[0026] The filter module includes: capacitor C5, resistor R7, and resistor R8;

[0027] One end of capacitor C5 is connected to one end of resistor R7, one end of resistor R8, the +IN pin of operational amplifier U1, and the IN pin of operational amplifier U2. The other end of capacitor C5 is connected to the other end of resistor R7 and ground. The other end of resistor R8 is connected to the input power supply PG12V.

[0028] exc- and exc+ are the excitation input signals, and N_exc- and P_exc+ are the excitation output signals. Operational amplifiers U1 and U2 are RS8471YTDC8 operational amplifiers, which amplify the excitation output signals. The RS8471YTDC8 operational amplifier has a maximum peak output current of 2.5A, which can directly drive the excitation coil of the rotary transformer in the rotary encoder, meeting the requirements of high-load scenarios. Compared with ordinary op-amps, its high current characteristics reduce the complexity of external drive circuit design and improve system integration. This operational amplifier has a high-speed response, high slew rate (65V / μs), and 25MHz gain-bandwidth product, which ensures rapid establishment of high-frequency excitation signals and reduces waveform distortion. This operational amplifier has a wide voltage adaptability (4.5V~24V), allowing stable operation in different power supply environments and adapting to the power supply configurations of various encoding systems. The operational amplifier's input and output terminals support rail-to-rail, maximizing the dynamic range of the signal. Combined with high open-loop gain (100dB) and low noise (20μVpp), it ensures signal integrity. The RS8471YTDC8 operational amplifier features built-in short-circuit protection and thermal shutdown, which improves system reliability under overload or high temperature conditions and protects encoder circuitry from damage.

[0029] Resistors R2, R5, R10, and R13 are resistors for adjusting the amplification factor. The amplification factor can be changed by modifying the resistance value. For example, when exc- is a 3.6Vp-p signal, where Vp-p is the peak-to-peak voltage, the excitation amplification factor of operational amplifier U1 is provided by resistors R2 and R5, denoted as A1. Then A1 = R2 / R15 = 1, and the output signal is 1 × 3.6Vp-p = 3.6Vp-p.

[0030] When exc+ is a 3.6Vp-p signal, the drive amplification factor of operational amplifier U2 is provided by resistors R10 and R13, denoted as A2. Then A2 = R13 / R10 = 1, and the output signal is 1 × 3.6Vp-p = 3.6Vp-p. Resistors R7 and R8 are voltage divider resistors used to set the common-mode voltage REF to 3.75V. REF = (R7 / (R7+R8)) x 12V = (10 / 32) x 12V = 3.75V.

[0031] When REF is 3.75V, the common-mode voltage output by operational amplifier U1 is 3.75V×A1=3.75V, and the common-mode voltage output by operational amplifier U1 is 3.75V×A2=3.75V.

[0032] Resistor R8 is a pull-up resistor that pulls the operational amplifier chip pins high to PG12V, ensuring stable pin levels and preventing interference from being introduced by floating pins.

[0033] Capacitors C1, C5, C10, and C11 are filter capacitors used to reduce noise such as ripple and interference in the signal, provide a more stable DC output, or protect subsequent circuits from unintentional interference.

[0034] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rotary encoder excitation amplifier circuit on an industrial servo drive, characterized by, It includes: power supply module, communication module, and filtering module; The power supply module is connected to the communication module and the filtering module, and the communication module is connected to the filtering module. The communication module includes: operational amplifier U1, operational amplifier U2, resistor R5, resistor R2, capacitor C1, resistor R10, resistor R13, and capacitor C7; One end of resistor R5 is connected to the -IN pin of operational amplifier U1, one end of resistor R2, and one end of capacitor C1. The other end of capacitor C1 is connected to the other end of resistor R2 and the OUT pin of operational amplifier U1. The input power supply PG12V is connected to the +Vs pin of operational amplifier U1, and the -Vs pin of operational amplifier U1 is connected to ground. One end of resistor R10 is connected to the -IN pin of operational amplifier U2, one end of resistor R13, and one end of capacitor C7. The other end of capacitor C7 is connected to the other end of resistor R13 and the OUT pin of operational amplifier U2. The input power supply PG12V is connected to the +Vs pin of operational amplifier U2, and the -Vs pin of operational amplifier U2 is connected to ground.

2. The rotary encoder excitation amplifier circuit on an industrial servo drive of claim 1, wherein, The power module includes: capacitor C10 and capacitor C11; The input power supply PG12V is connected to one end of capacitor C10 and one end of capacitor C11, and the other ends of capacitor C10 and capacitor C11 are connected to ground.

3. The rotary encoder excitation amplifier circuit on an industrial servo drive of claim 1, wherein, The filter module includes: capacitor C5, resistor R7, and resistor R8; One end of capacitor C5 is connected to one end of resistor R7, one end of resistor R8, the +IN pin of operational amplifier U1, and the IN pin of operational amplifier U2. The other end of capacitor C5 is connected to the other end of resistor R7 and ground. The other end of resistor R8 is connected to the input power supply PG12V.

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