CN113029206B - Vernier gear type magnetic sensitive multi-turn encoder - Google Patents

Abstract

The present invention discloses a vernier gear type magnetic sensitive multi-turn encoder, comprising a housing, a cover plate, a main gear, a vernier gear, a main shaft, a vernier gear rotating shaft and a circuit board, wherein the main gear is crimped to one end of the main shaft, the vernier gear is crimped to one end of the vernier gear rotating shaft, the main gear and the vernier gear are respectively installed with magnetic steel, and a plurality of magnetic sensitive chips are respectively arranged on the same side of the circuit board, which are respectively located above the magnetic steel of the main gear and the vernier gear, and are used to collect the main gear angle and the vernier gear angle, and the number of rotations of the main gear is calculated by the data processing module on the circuit board, and a multi-turn absolute position signal is generated by the signal processing circuit. The beneficial effect is that a main gear and a plurality of vernier gears are provided, and different tooth differences are set between them. After each certain number of rotations, the tooth difference between the main gear and the vernier gear will continue to accumulate. By reading and calculating the accumulated tooth difference, the number of rotations of the main shaft is obtained, and the number of rotations is measured.

Description

A Vernier Gear Magnetic Multi-Turn Encoder

Technical Field

The invention relates to the technical field of encoders, and in particular to a vernier gear type magnetically sensitive multi-turn encoder.

Background Art

At present, in the encoder industry, there are two main types of multi-turn encoders. The first type is in the form of a counter, which adds one for each positive rotation of the spindle and subtracts one for each reverse rotation. This method requires the product to be powered on before counting, and the power cannot be cut off during operation. If the power is cut off, the recorded number of turns will be lost. In this method, there is a variant that uses a battery or a Wiegand coil to continuously power the counter so that the recorded number of turns information is not lost. However, this method only reflects the relative number of turns of the product, not the absolute number of turns of the product, and there is unreliability in application. The second type is to use a gear set to reflect the absolute number of turns of the product. This gear set generally has a reduction gear set and a multi-stage photoelectric gear set. The reduction gear set reduces one turn of the spindle to 1/n of the sensor chip through the gear ratio of the gear. This method will greatly reduce the resolution of the sensor chip. The multi-stage photoelectric gear set is continuously driven by gears one level at a time, and the transmission ratio between the previous gear and the next gear is 4:1. Gray code channels are engraved on each gear stage, and the Gray code information on each gear stage is read through photoelectric tubes and optical couplers, and then combined into the number of revolutions of the product as a whole. This method can obtain an infinite number of counted revolutions through the accumulated gears one level at a time. However, this method has the disadvantage of being larger in size when facing the counting of fewer revolutions. In addition, the number of revolutions counted must be an exponential multiple of 4, and the number of counted revolutions cannot be flexibly selected.

In view of the problems of the above-mentioned multi-turn encoder solution, a multi-turn counting function is realized in the form of a vernier gear through an innovative algorithm. The vernier gear method sets a main gear and several vernier gears, and sets different tooth differences between the main gear and the vernier gear. After each certain number of turns, the tooth difference between the main gear and the vernier gear will continue to accumulate. By reading and calculating the accumulated tooth difference, the number of turns of the main shaft at the current position can be obtained. In this way, the measurement of the number of turns of multiple turns is realized. The present invention is a measurement of absolute turns, and solves the problem of resolution of the reduction gear set and the problem of large volume and inflexible counting of turns of the multi-stage photoelectric gear set when the number of turns is small.

Summary of the invention

In view of the problems existing in the prior art, a vernier gear type magnetic sensitive multi-turn encoder is provided, which utilizes the principle of the vernier gear to realize the absolute value of flexible circle counting in a smaller space without sacrificing the resolution of the magnetic sensitive chip.

The above technical solution specifically includes:

1. A vernier gear type magnetic sensitive multi-turn encoder, comprising:

A housing, wherein a main shaft through hole is provided on the housing, and a plurality of blind holes are provided on one side of the main shaft through hole;

A cover plate, the cover plate is connected to the housing and has a wire outlet on one side of the cover plate;

a main shaft, the main shaft passing through the main shaft through hole and disposed in the housing;

A main gear, which is crimped to one end of the main shaft and is provided with a first magnetic steel mounting hole;

A main gear magnet, wherein the main gear magnet is disposed in the first magnet mounting hole;

A plurality of cursor gear shafts, wherein the cursor gear shafts are arranged on one side of the main shaft through the blind hole;

A plurality of vernier gears, wherein the vernier gear is crimped to one end of the vernier gear shaft and is provided with a second magnetic steel mounting hole, wherein the vernier gear magnets are respectively mounted in the second magnetic steel mounting holes, and the vernier gears are independently meshed with the main gear for transmission;

A plurality of magnetic isolation plates, wherein the magnetic isolation plates are respectively disposed between the main gear and the cursor gear;

A circuit board is provided on a step in the shell, between the cover plate and the magnetic isolation plate, a first magnetic sensitive chip and a plurality of second magnetic sensitive chips are provided on the same side of the circuit board, the first magnetic sensitive chip is located above the main gear magnet and is used to collect the main gear angle, and the second magnetic sensitive chip is located above the vernier gear magnet and is used to collect the vernier gear angle, the number of main gear rotations is calculated according to the main gear angle and the vernier gear angle, and a corresponding multi-turn absolute position signal is generated.

Preferably, in the vernier gear type magnetically sensitive multi-turn encoder, the main shaft and the housing are connected by a sleeve or a bearing.

Preferably, in the vernier gear type magnetically sensitive multi-turn encoder, the cover plate is snap-connected to the shell.

Preferably, in the vernier gear type magnetic sensitive multi-turn encoder, the circuit board comprises:

a voltage conversion unit, used for converting a supply voltage of an external power source into an operating voltage required by an internal chip included in the circuit board;

A first angle acquisition unit, connected to the voltage conversion unit, for acquiring the main gear angle and generating a corresponding main gear angle signal;

A second angle acquisition unit, connected to the voltage conversion unit, for acquiring the vernier gear angle and generating a corresponding vernier gear angle signal;

a signal processing unit, connected to the first angle acquisition unit, the second angle acquisition unit and the voltage conversion unit, respectively, for calculating the number of rotations of the main gear according to the main gear angle signal and the vernier gear angle signal, and combining the number of rotations of the main gear and the main gear angle into a multi-turn absolute position data and then converting it into the corresponding multi-turn absolute position signal;

A differential signal conversion unit is connected to the voltage conversion unit and the signal processing unit respectively, and is used to convert the multi-turn absolute position signal into a differential multi-turn absolute position signal.

Preferably, in the vernier gear type magnetic sensitive multi-turn encoder, the voltage conversion unit uses a first chip and a second chip to realize the voltage conversion function, and a power supply circuit is also provided on the circuit board;

The input end of the power supply circuit is connected to the external power supply, and is sequentially connected to a protection fuse, a diode, a TVS diode, the first chip and the second chip;

The anode of the diode is connected to the protection fuse, the cathode of the diode and the cathode of the TVS diode are respectively connected to a first node, and the anode of the TVS diode is grounded;

The first pin of the first chip is respectively connected to one end of a first capacitor and the first node, and the other end of the first capacitor is grounded;

The second pin of the first chip is suspended, and the third pin and the fourth pin are grounded;

The fifth pin of the first chip is connected to one end of a second capacitor, and the other end of the second capacitor is grounded;

The fifth pin of the first chip is the first voltage output terminal of the power supply circuit;

The first pin of the second chip is respectively connected to one end of a third capacitor and a second node, the other end of the third capacitor is grounded, and the second node is located between the cathode of the TVS diode and the first node;

The second pin of the second chip is suspended, and the third pin and the fourth pin are grounded;

The fifth pin of the second chip is connected to one end of a fourth capacitor, and the other end of the fourth capacitor is grounded;

The fifth pin of the second chip is the second voltage output terminal of the power supply circuit;

The power supply circuit provides two operating voltage values for the internal chip included in the circuit board through the first voltage output terminal and the second voltage output terminal.

Preferably, in the vernier gear type magnetic sensitive multi-turn encoder, the first angle acquisition unit uses the first magnetic sensitive chip to realize the function of acquiring the main gear angle, and a first angle sampling circuit is also provided on the circuit board, including:

The fourth pin of the first magnetic sensitive chip is connected to one end of a fifth capacitor, and the other end of the fifth capacitor is grounded;

The fifth pin of the first magnetic sensor chip is the first slave output pin, the sixth pin is the first slave input pin, the seventh pin is the first clock signal pin, and the eighth pin is the first chip select signal pin;

The ninth pin of the first magnetic sensitive chip is respectively connected to the second voltage output terminal and one end of a sixth capacitor, and the other end of the sixth capacitor is grounded;

The eleventh pin and the twelfth pin of the first magnetic sensitive chip are grounded;

The first pin, the second pin, the third pin, the tenth pin, the thirteenth pin, the fourteenth pin, the fifteenth pin and the sixteenth pin of the first magnetic sensitive chip are all suspended;

The main gear angle collected by the first angle sampling circuit generates and outputs the corresponding main gear angle signal through the first slave output pin, the first slave input pin, the first clock signal pin and the first chip select signal pin of the first magnetic sensor chip.

Preferably, in the vernier gear type magnetic sensitive multi-turn encoder, the second angle acquisition unit uses the second magnetic sensitive chip to realize the function of acquiring the vernier gear angle, and a second angle sampling circuit is also provided on the circuit board, including:

The fourth pin of the second magnetic sensitive chip is connected to one end of a seventh capacitor, and the other end of the seventh capacitor is grounded;

The fifth pin of the second magnetic sensor chip is the second slave output pin, the sixth pin is the second slave input pin, the seventh pin is the second clock signal pin, and the eighth pin is the second chip select signal pin;

The ninth pin of the second magnetic sensor chip is respectively connected to the second voltage output terminal and one end of an eighth capacitor, and the other end of the eighth capacitor is grounded;

The eleventh pin and the twelfth pin of the second magnetic sensitive chip are grounded;

The first pin, the second pin, the third pin, the tenth pin, the thirteenth pin, the fourteenth pin, the fifteenth pin and the sixteenth pin of the second magnetic sensitive chip are all suspended;

The vernier gear angle collected by the second angle sampling circuit generates and outputs the corresponding vernier gear angle signal through the second slave output pin, the second slave input pin, the second clock signal pin and the second chip select signal pin of the second magnetic sensor chip.

Preferably, in the vernier gear type magnetic sensitive multi-turn encoder, the signal processing unit adopts a fourth chip to realize the function of calculating the multi-turn absolute position data, and adopts a third chip to realize the function of receiving and converting the main gear angle signal and the vernier gear angle signal. A signal processing circuit is also provided on the circuit board, including:

The twelfth pin of the third chip is connected to the fifth pin of the first magnetic sensitive chip, the thirteenth pin is connected to the sixth pin of the first magnetic sensitive chip, the fourteenth pin is connected to the seventh pin of the first magnetic sensitive chip, and the sixteenth pin is connected to the eighth pin of the first magnetic sensitive chip, and

The seventeenth pin of the third chip is connected to the fifth pin of the second magnetic sensitive chip, the eighteenth pin is connected to the sixth pin of the second magnetic sensitive chip, the nineteenth pin is connected to the seventh pin of the second magnetic sensitive chip, and the twenty-second pin is connected to the eighth pin of the second magnetic sensitive chip;

The fourth chip is connected to the third chip, and is used to generate the corresponding multi-turn absolute position data according to the main gear angle signal and the vernier gear angle signal received by the third chip;

The signal processing circuit converts the multi-turn absolute position data into the multi-turn absolute position signal through the third chip and outputs the signal.

Preferably, in the vernier gear type magnetic sensitive multi-turn encoder, the differential signal conversion unit uses a fifth chip, a sixth chip and a seventh chip to realize the function of converting the multi-turn absolute position signal into a corresponding differential signal, and a differential signal conversion circuit is also provided on the circuit board, including:

The first pin of the fifth chip is connected to one end of a ninth capacitor, and the other end of the ninth capacitor is grounded;

The fourth pin of the fifth chip is grounded;

The seventh pin and the eighth pin of the fifth chip are respectively connected to a differential input signal, and connected to the fourth pin of the sixth chip through the second pin;

The third pin of the fifth chip is connected to the fourth pin of the sixth chip;

The fifth pin and the sixth pin of the fifth chip respectively output the differential multi-turn absolute position signal;

The first pin of the sixth chip is respectively connected to one end of a tenth capacitor and the second voltage output end, and the other end of the tenth capacitor is grounded;

The sixth pin of the sixth chip is respectively connected to one end of an eleventh capacitor and the first voltage output end, and the other end of the eleventh capacitor is grounded;

The third pin of the sixth chip is respectively connected to the second pin of the third chip, one end of a first resistor and one end of a twelfth capacitor, the other end of the first resistor is connected to the second voltage output end, and the other end of the twelfth capacitor is grounded;

The second pin and the fifth pin of the sixth chip are grounded;

The sixth chip performs level conversion on the differential input signal and inputs the signal to the third chip;

The first pin of the seventh chip is respectively connected to one end of a thirteenth capacitor and the second voltage output end, and the other end of the thirteenth capacitor is grounded;

The sixth pin of the seventh chip is respectively connected to one end of a fourteenth capacitor and the first voltage output end, and the other end of the fourteenth capacitor is grounded;

The third pin of the seventh chip is respectively connected to the fourth pin of the third chip, one end of a second resistor and one end of a fifteenth capacitor, the other end of the second resistor is connected to the second voltage output end, and the other end of the fifteenth capacitor is grounded;

The fifth pin of the seventh chip is connected to one end of a third resistor, and the other end of the third resistor is connected to the second voltage output end;

The second pin of the seventh chip is grounded;

The seventh chip performs level conversion on the multi-turn absolute position signal including the differential input signal and outputs the signal to the fifth chip;

The differential signal conversion circuit is used for converting the single-ended multi-turn absolute position signal into a differential multi-turn absolute position signal.

Preferably, in the vernier gear type magnetically sensitive multi-turn encoder, the signal processing unit calculates the number of rotations of the main gear by the following formula:

in,

θ1 is the main gear angle;

θ2 is the vernier gear angle;

△θ is the angular difference between the main gear and the vernier gear;

n is the number of teeth of the main gear;

n-1 is the number of teeth of the vernier gear;

x is the number of revolutions of the main gear.

After calculating the number of rotations of the main gear, a calibration and correction process for the number of rotations of the main gear is performed. The calibration and correction process is implemented using the following formula:

in,

x' is used to represent the number of revolutions of the main gear after the verification and correction process;

ROUND is used to indicate the rounding function.

The beneficial effect of the technical solution of the present invention is that, through an innovative algorithm, a multi-turn counting function is realized in the form of a vernier gear. The vernier gear method sets a main gear and several vernier gears, and different tooth differences are set between the main gear and the vernier gear. After each rotation of a certain number of circles, the tooth difference between the main gear and the vernier gear will continue to accumulate. By reading and calculating the accumulated tooth difference, the number of circles rotated by the main shaft at the current position is obtained. In this way, the measurement of the number of multiple circles is realized. At the same time, through the verification algorithm, the product can adapt to larger gear precision errors.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a vernier gear type magnetically sensitive multi-turn encoder in a preferred embodiment of the present invention;

FIG2 is a schematic structural diagram of data processing on a circuit board of a vernier gear type magnetic sensitive multi-turn encoder in a preferred embodiment of the present invention;

FIG3 is a circuit diagram of a power supply circuit of a vernier gear type magnetic sensitive multi-turn encoder in a preferred embodiment of the present invention;

FIG4 is a circuit diagram of a first angle sampling circuit of a vernier gear type magnetic sensitive multi-turn encoder in a preferred embodiment of the present invention;

FIG5 is a circuit diagram of a second angle sampling circuit of a vernier gear type magnetic sensitive multi-turn encoder in a preferred embodiment of the present invention;

FIG6 is a circuit diagram of a signal processing circuit of a vernier gear type magnetic sensitive multi-turn encoder in a preferred embodiment of the present invention;

FIG7 is a circuit diagram of a differential signal conversion circuit of a vernier gear type magnetic sensitive multi-turn encoder in a preferred embodiment of the present invention;

FIG8 is a schematic structural diagram of a vernier gear type magnetic sensitive multi-turn encoder using a vernier gear in a preferred embodiment of the present invention;

FIG9 is a schematic diagram showing the relationship between the angle difference between the main gear and the vernier gear of a vernier gear type magnetic sensitive multi-turn encoder using a vernier gear in one counting cycle in a preferred embodiment of the present invention;

FIG10 is a schematic diagram showing the relationship between the number of turns and the angle difference of a vernier gear type magnetic sensitive multi-turn encoder in a counting cycle using a vernier gear in a preferred embodiment of the present invention;

FIG11 is a schematic structural diagram of a vernier gear type magnetic sensitive multi-turn encoder using two vernier gears in a preferred embodiment of the present invention;

FIG. 12 is a schematic diagram showing the relationship between the angle difference between the main gear and the vernier gear in one counting cycle of a vernier gear type magnetic sensitive multi-turn encoder using two vernier gears in a preferred embodiment of the present invention.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

As shown in FIG1 , the present invention discloses a vernier gear type magnetic sensitive multi-turn encoder, comprising:

A housing 1 is provided with a spindle through hole 11, and a plurality of blind holes 12 are provided on one side of the spindle through hole 11;

A cover plate 2, the cover plate 2 is connected to the housing 1, and a wire outlet 21 is provided on one side of the cover plate 2;

A main shaft 3, which passes through the main shaft through hole 11 and is disposed in the housing 1;

A main gear 4, which is crimped to one end of the main shaft 3 and is provided with a first magnetic steel mounting hole 41;

A main gear magnet 42, the main gear magnet 42 is disposed in the first magnet mounting hole 41;

A plurality of cursor gear shafts 5, wherein the cursor gear shafts 5 are arranged on one side of the main shaft 11 through a blind hole 12;

A plurality of vernier gears 6, the vernier gear 6 is crimped to one end of the vernier gear shaft 5, and is provided with a second magnetic steel mounting hole 61, a plurality of vernier gear magnets 62 are respectively mounted in the second magnetic steel mounting holes 61, and the plurality of vernier gears 6 are independently meshed and driven with the main gear 4;

A plurality of magnetic isolation plates 7, wherein the magnetic isolation plates 7 are respectively disposed between the main gear 4 and the cursor gear 6;

A circuit board 8 is arranged on a step 13 in the shell 1, between the cover plate 2 and the magnetic isolation plate 7. A first magnetic sensitive chip 81 and a plurality of second magnetic sensitive chips 82 are respectively arranged on the same side of the circuit board 8. The first magnetic sensitive chip 81 is located above the main gear magnet 42 and is used to collect the main gear angle. The second magnetic sensitive chip 82 is located above the vernier gear magnet 62 and is used to collect the vernier gear angle. The number of main gear rotations is calculated based on the main gear angle and the vernier gear angle and a corresponding multi-turn absolute position signal is generated.

In this embodiment, a combination of a main gear 4 and a vernier gear 6 is used in the multi-turn encoder. The number of teeth of the main gear 4 and the number of teeth of the vernier gear 6 are set to a certain difference in the number of teeth. After a certain number of turns, the angle of the main gear 4 and the angle of the vernier gear 6 have a specific angle difference. The current number of turns can be calculated by formula calculation. Then the number of turns and the angle of the main shaft are combined and output, which is the multi-turn absolute position data of the encoder.

Specifically, a D-shaped hole is opened in the center of the main gear 4, so that the main gear 4 is tightly pressed on the top of the main shaft 3, and a through hole 63 is opened in the center of the vernier gear 6. The vernier gear shaft 5 passes through the vernier gear 6 through the through hole 63, and the lower end is tightly inserted into the blind hole 12 of the housing 1 to fix the vernier gear 6 on the housing 1. The main gear 4 and the vernier gear 6 are respectively provided with an initial angle position.

Specifically, the module of the main gear 4 and the module of the vernier gear 6 are both 0.3, the number of teeth of the main gear 4 is set to 16, and the number of teeth of the vernier gear 6 is set to 15.

Specifically, the main gear magnet 42 is installed on the main gear 4, and the vernier gear magnet 62 is installed on the vernier gear 6. The magnetic isolation plate 7 is made of soft magnetic material. The main gear magnet 42 and the vernier gear magnet 62 are separated by the magnetic isolation plate 7. The magnetic isolation plate 7 is installed in the slot of the shell 1. The magnetic isolation plate 7 is made of soft magnetic material to avoid magnetic field interference between the main gear magnet 42 and the vernier gear magnet 62.

Specifically, the circuit board 8 is installed on the first step 14 of the housing 1. The circuit board has a main gear magnetic sensitive chip 81 and a vernier gear magnetic sensitive chip 82. The main gear magnetic sensitive chip 81 and the vernier gear magnetic sensitive chip 82 are arranged on the same side of the circuit board 8, facing the main gear magnet 42 and the vernier gear magnet 62. The main gear magnetic sensitive chip 81 collects the angle of the current main gear 4 after a certain number of rotations relative to the initial angle position, and the vernier gear magnetic sensitive chip 82 collects the angle of the current vernier gear 6 after a certain number of rotations relative to the initial angle position. The circuit board 8 calculates the number of turns of the current main shaft 2 according to a preset algorithm, and then combines the number of turns and the current angle information of the main shaft 2, that is, the angle of the current main gear 4, into the final multi-turn absolute position data. Finally, the circuit board 8 converts the multi-turn absolute position data into a corresponding signal and outputs it. The final output signal type can be an analog signal, an SSI signal, an SPI signal, an RS485 signal, or a CANopen signal. In the embodiment of the present application, the final output signal type is described by taking an SSI signal and an SPI signal as examples.

In a preferred embodiment, in the vernier gear type magnetic sensitive multi-turn encoder, the main shaft 2 and the housing 1 are connected by a sleeve or a bearing.

In this embodiment, the main shaft 2 and the housing 1 are preferably installed in a sleeve connection manner, the housing 1 and the gear are made of injection molding, and the main shaft 2 is made of stainless steel.

In a preferred embodiment, in the vernier gear type magnetic sensitive multi-turn encoder, the cover plate 2 is snap-connected to the housing 1 .

In this embodiment, the cover plate 2 is snap-connected to the housing 1, and a wire outlet is provided on one side of the cover plate 1. The wire harness is plugged into the interface on the circuit board through the wire outlet 21 to output the multi-turn absolute position information generated by the multi-turn encoder.

As shown in FIG. 2 , in a preferred embodiment, the circuit board 8 includes:

A voltage conversion unit 801, used to convert a supply voltage of an external power source into an operating voltage required by an internal chip included in the circuit board;

The first angle acquisition unit 802 is connected to the voltage conversion unit 801 and is used to acquire the main gear angle and generate a corresponding main gear angle signal;

The second angle acquisition unit 803 is connected to the voltage conversion unit 801 and is used to acquire the vernier gear angle and generate a corresponding vernier gear angle signal;

a signal processing unit 804, connected to the first angle acquisition unit 802, the second angle acquisition unit 803 and the voltage conversion unit 801, respectively, for calculating the number of rotations of the main gear according to the main gear angle signal and the vernier gear angle signal, and combining the number of rotations of the main gear and the main gear angle into a multi-turn absolute position data and then converting it into a corresponding multi-turn absolute position signal;

A differential signal conversion unit 805 is connected to the voltage conversion unit 801 and the signal processing unit 804 respectively, and is used to convert the multi-turn absolute position signal into a differential multi-turn absolute position signal.

In this embodiment, a voltage conversion unit 801 is provided on the circuit board 8 to convert the supply voltage of the external power supply with a wide voltage range of 5.5V-30V into the 5V and 3.3V voltages required for the operation of the internal chip of the circuit board 8. That is, the first angle acquisition unit 802, the second angle acquisition unit 803, the signal processing unit 804 and the differential signal conversion unit 805 are powered respectively, and the angle of the current main gear 4 acquired by the first angle acquisition unit 802 and the angle of the current vernier gear 6 acquired by the second angle acquisition unit 803 are input to the signal processing unit 804, and the number of rotations of the main gear is calculated, and then the number of rotations of the main gear and the main gear angle are combined into multi-turn absolute position data and the corresponding multi-turn absolute position SPI signal is output, and then converted into a differential multi-turn absolute position SSI signal through the differential signal conversion unit 805.

The first angle acquisition unit 802, the second angle acquisition unit 803 and the signal processing unit 804 require an operating voltage of 3.3V, and the differential signal conversion unit 805 performs level conversion on the differential signal, so the required operating voltages are 3.3V and 5V respectively.

As shown in FIG. 3 , in a preferred embodiment, the voltage conversion unit 801 uses a first chip U1 and a second chip U2 to implement the voltage conversion function, and a power supply circuit L1 is also provided on the circuit board 8;

The input terminal VCC of the power circuit L1 is connected to an external power source, and is sequentially connected to a protection fuse FB1, a diode D1, a TVS diode D2, a first chip U1 and a second chip U2;

The anode of the diode D1 is connected to the protection fuse FB1, the cathode of the diode D1 and the cathode of the TVS diode D2 are respectively connected to a first node J1, and the anode of the TVS diode D2 is grounded;

The first pin 1 of the first chip U1 is respectively connected to one end of a first capacitor C1 and the first node J1, and the other end of the first capacitor C1 is grounded;

The second pin 2 of the first chip U1 is suspended, and the third pin 3 and the fourth pin 4 are grounded;

The fifth pin 5 of the first chip U1 is connected to one end of a second capacitor C2, and the other end of the second capacitor C2 is grounded;

The fifth pin 5 of the first chip U1 is the first voltage output terminal OUT1 of the power supply circuit L1;

The first pin 1 of the second chip U2 is respectively connected to one end of a third capacitor C3 and a second node J2, the other end of the third capacitor C3 is grounded, and the second node J2 is located between the cathode of the TVS diode D2 and the first node J1;

The second pin 2 of the second chip U2 is suspended, and the third pin 3 and the fourth pin 4 are grounded;

The fifth pin 5 of the second chip U2 is connected to one end of a fourth capacitor C4, and the other end of the fourth capacitor C4 is grounded;

The fifth pin 5 of the second chip U2 is the second voltage output terminal OUT2 of the power supply circuit L1;

The power supply circuit L1 provides two operating voltage values for the internal chips included in the circuit board 8 through the first voltage output terminal OUT1 and the second voltage output terminal OUT2.

In this embodiment, the power supply circuit L1 converts the input 5.5V-30V wide voltage into the 5V and 3.3V voltages required for the internal chip to work. The first chip U1 and the second chip U2 are level conversion chips respectively. The input terminal VCC of the power supply circuit L1 is connected to the 5.5V-30V wide voltage of the external power supply, and the power supply is protected by the fuse FB1, the unidirectional diode D1, and the TVS tube D2. The level conversion chip U1 converts the 5.5-30V voltage into 5V and outputs it through the first voltage output terminal OUT1, and the level conversion chip U2 converts the 5.5-30V voltage into 3.3V and outputs it through the second voltage output terminal OUT2. The first capacitor C1 and the first capacitor C2 filter the input and output voltages at both ends of the level conversion chip U1, and the third capacitor C3 and the fourth capacitor C4 filter the input and output voltages at both ends of the level conversion chip U2.

Specifically, the fuse FB1 uses a chip ferrite bead, model CBG201209U601; the model of the unidirectional diode D1 is 1N4007W/A7; the model of the TVS tube D2 is SMF28A; the model of the level conversion chip U1 is TPS7B6950DBVR; the model of the level conversion chip U2 is TPS7B6933DBVR; the model of the first capacitor C1 and the first capacitor C2 is 10UF/50V, and the model of the third capacitor C3 and the fourth capacitor C4 is 4.7UF/16V.

As shown in FIG. 4 , in a preferred embodiment, the first angle acquisition unit 802 uses the first magnetic sensor chip MU1 to realize the function of collecting the main gear angle, and a first angle sampling circuit L2 is also provided on the circuit board 8, including:

The fourth pin 4 of the first magnetic sensor chip MU1 is connected to one end of a fifth capacitor C5, and the other end of the fifth capacitor C5 is grounded;

The fifth pin 5 of the first magnetic sensor chip MU1 is the first slave output pin M_MISO, the sixth pin is the first slave input pin M_MOSI, the seventh pin is the first clock signal pin M_SCK, and the eighth pin is the first chip select signal pin M_CSN;

The ninth pin 9 of the first magnetic sensor chip MU1 is respectively connected to the second voltage output terminal OUT2 and one end of a sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded;

The eleventh pin 11 and the twelfth pin 12 of the first magnetic sensor chip MU1 are grounded;

The first pin 1, the second pin 2, the third pin 3, the tenth pin 10, the thirteenth pin 13, the fourteenth pin 14, the fifteenth pin 15, and the sixteenth pin 16 of the first magnetic sensor chip MU1 are all suspended;

The master gear angle collected by the first angle sampling circuit L2 generates and outputs the corresponding master gear angle SPI signal through the first slave output pin M_MISO, the first slave input pin M_MOSI, the first clock signal pin M_SCK and the first chip select signal pin M_CSN of the first magnetic sensor chip MU1.

In this embodiment, the first magnetic chip MU1 of the first angle sampling circuit L2 on the circuit board 8 detects the main gear angle, and the ninth pin 9 on the first magnetic chip MU1, that is, the power input terminal VDD, is connected to the 3.3V working voltage of the second voltage output terminal OUT2 of the power circuit L1, and the sixth capacitor C6 is used to filter out the clutter interference. The eleventh pin 11 and the twelfth pin 12, that is, the VSS pin and the TEST pin are connected to the ground in parallel, and the fourth pin M_HVPP pin is grounded through the fifth capacitor C5. The main gear angle information detected by the first magnetic chip MU1 is sent to the signal processing circuit L1 through the SPI signal, and the SPI signal of the main gear angle is generated through the fifth pin M_MISO as the slave output pin, the sixth pin M_MOSI as the slave input pin, the seventh pin M_SCK as the clock signal pin, and the eighth pin M_CSN as the chip select signal pin.

Specifically, the model of the first magnetic sensor chip MU1 is MT6825; the model of the fifth capacitor C5 is 1UF/16V; and the model of the sixth capacitor C6 is 100NF/16V.

As shown in FIG. 5 , in a preferred embodiment, the second angle acquisition unit 803 uses a second magnetic sensitive chip MU2 to realize the function of collecting the vernier gear angle, and a second angle sampling circuit L3 is also provided on the circuit board 8, including:

The fourth pin 4 of the second magnetic sensor chip MU2 is connected to one end of a seventh capacitor C7, and the other end of the seventh capacitor C7 is grounded;

The fifth pin 5 of the second magnetic sensor chip MU2 is the second slave output pin V_MISO, the sixth pin 6 is the second slave input pin V_MOSI, the seventh pin 7 is the second clock signal pin V_SCK, and the eighth pin 8 is the second chip select signal pin V_CSN;

The ninth pin 9 of the second magnetic sensor chip MU2 is respectively connected to the second voltage output terminal OUT2 and one end of an eighth capacitor C8, and the other end of the eighth capacitor C8 is grounded;

The eleventh pin 11 and the twelfth pin 12 of the second magnetic sensing chip MU2 are grounded;

The first pin 1, the second pin 2, the third pin 3, the tenth pin 10, the thirteenth pin 13, the fourteenth pin 14, the fifteenth pin 15, and the sixteenth pin 16 of the second magnetic sensor chip MU2 are all suspended;

The vernier gear angle collected by the second angle sampling circuit L3 generates and outputs the corresponding vernier gear angle SPI signal through the second slave output pin V_MISO, the second slave input pin V_MOSI, the second clock signal pin V_SCK and the second chip select signal pin V_CSN of the second magnetic sensor chip MU2.

In this embodiment, the second magnetic chip MU2 of the second angle sampling circuit L3 on the circuit board 8 detects the vernier gear angle, and the ninth pin 9 on the second magnetic chip MU2, i.e., the power input terminal VDD, is connected to the 3.3V working voltage of the second voltage output terminal OUT2 of the power circuit L1, and the eighth capacitor C8 is used to filter out the clutter interference. The eleventh pin 11 and the twelfth pin 12, i.e., the VSS pin and the TEST pin, are connected to the ground in parallel, and the fourth pin V_HVPP pin is connected to the ground through the seventh capacitor C7. The vernier gear angle information detected by the second magnetic chip MU2 is sent to the signal processing circuit L1 through the SPI signal, and the SPI signal of the vernier gear angle is generated through the fifth pin V_MISO as the slave output pin, the sixth pin V_MOSI as the slave input pin, the seventh pin V_SCK as the clock signal pin, and the eighth pin V_CSN as the chip select signal pin.

Specifically, the model of the second magnetic sensor chip MU2 is MT6825; the model of the seventh capacitor C7 is 1UF/16V; and the model of the eighth capacitor C8 is 100NF/16V.

As shown in FIG6 , in a preferred embodiment, the signal processing unit 804 uses a fourth chip U4 to realize the function of calculating the multi-turn absolute position data, and uses a third chip U3 to realize the function of receiving and converting the main gear angle signal and the vernier gear angle signal. A signal processing circuit L4 is also provided on the circuit board 8, including:

The twelfth pin B6 of the third chip U3 is connected to the fifth pin M_MISO of the first magnetic sensor chip MU1, the thirteenth pin B7 is connected to the sixth pin M_MOSI of the first magnetic sensor chip MU1, the fourteenth pin B8 is connected to the seventh pin M_SCK of the first magnetic sensor chip MU1, and the sixteenth pin C1 is connected to the eighth pin M_CSN of the first magnetic sensor chip MU1;

The seventeenth pin C2 of the third chip U3 is connected to the fifth pin V_MISO of the second magnetic sensor chip MU2, the eighteenth pin C8 is connected to the sixth pin V_MOSI of the second magnetic sensor chip MU2, the nineteenth pin D2 is connected to the seventh pin V_SCK of the second magnetic sensor chip, and the twenty-second pin D6 is connected to the eighth pin V_CSN of the second magnetic sensor chip;

The fourth chip U4 is connected to the third chip U3, and is used to generate corresponding multi-turn absolute position data according to the main gear angle signal and the vernier gear angle SPI signal received by the third chip U3;

The signal processing circuit L4 converts the multi-turn absolute position data into a multi-turn absolute position SPI signal through the third chip U3 and outputs the signal.

In this embodiment, the signal processing circuit L4 on the circuit board 8 includes a third chip U3 and a fourth chip U4 using FPGA chips. The power input terminal VCC of the third chip U3 and the fourth chip U4 is connected to the 3.3V working voltage of the second voltage output terminal OUT2. The fourth chip U4 uses the main angle SPI signal and the vernier gear angle SPI signal input from the third chip U3 through SPI communication to calculate the number of circles of the current main shaft according to a preset algorithm. Then the circle data is combined with the single-circle angle data of the main gear, and the differential signal is input through the second pin MCU_MA of the third chip U3 and the fourth pin MCU_SLO to output the differential signal of the absolute position of multiple circles, and then output through the differential signal conversion circuit L5.

As shown in FIG. 7 , in a preferred embodiment, the differential signal conversion unit 805 uses a fifth chip U5, a sixth chip U6 and a seventh chip U7 to realize the function of converting the multi-turn absolute position signal into the corresponding differential signal. A differential signal conversion circuit L5 is also provided on the circuit board 8, including;

The first pin 1 of the fifth chip U5 is connected to one end of a ninth capacitor C9, and the other end of the ninth capacitor C9 is grounded;

The fourth pin 4 of the fifth chip U5 is grounded;

The seventh pin 7 and the eighth pin 8 of the fifth chip U5 are respectively connected to a differential input signal, and connected to the fourth pin 4 of the sixth chip U6 through the second pin 2;

The third pin 3 of the fifth chip U5 is connected to the fourth pin 4 of the sixth chip U6;

The fifth pin 5 and the sixth pin 6 of the fifth chip U5 respectively output differential multi-turn absolute position signals;

The first pin 1 of the sixth chip U6 is respectively connected to one end of a tenth capacitor C10 and the second voltage output terminal OUT2, and the other end of the tenth capacitor C10 is grounded;

The sixth pin 6 of the sixth chip U6 is respectively connected to one end of an eleventh capacitor C11 and the first voltage output terminal OUT1, and the other end of the eleventh capacitor C11 is grounded;

The third pin 3 of the sixth chip U6 is respectively connected to the second pin A2 of the third chip U3, one end of a first resistor R1 and one end of a twelfth capacitor C12, the other end of the first resistor R1 is connected to the second voltage output terminal OUT2, and the other end of the twelfth capacitor C12 is grounded;

The second pin 2 and the fifth pin 5 of the sixth chip U6 are grounded;

The sixth chip U6 performs level conversion on the differential input signal and inputs it to the third chip U3;

The first pin 1 of the seventh chip U7 is respectively connected to one end of a thirteenth capacitor C13 and the second voltage output end, and the other end of the thirteenth capacitor C13 is grounded.

The sixth pin 6 of the seventh chip U7 is respectively connected to one end of a fourteenth capacitor C14 and the first voltage output end, and the other end of the fourteenth capacitor C14 is grounded.

The third pin 3 of the seventh chip U7 is respectively connected to the fourth pin A5 of the third chip U3, one end of a second resistor R2, and one end of a fifteenth capacitor C15, the other end of the second resistor R2 is connected to the second voltage output terminal OUT2, and the other end of the fifteenth capacitor C15 is grounded;

The fifth pin 5 of the seventh chip U7 is connected to one end of a third resistor R3, and the other end of the third resistor R3 is connected to the second voltage output terminal OUT2;

The second pin 2 of the seventh chip U7 is grounded;

The seventh chip U7 performs level conversion on the multi-turn absolute position signal including the differential input signal and outputs it to the fifth chip U5;

The differential signal conversion circuit L5 is used to convert the single-ended multi-turn absolute position SPI signal into a differential multi-turn absolute position SSI signal.

In this embodiment, the differential signal conversion circuit L5 converts the single-ended SPI signal output by the third chip U3 into a differential SSI signal. The sixth chip U6 and the seventh chip U7 are level conversion chips, and the fifth chip U5 is a differential receiving and output chip. The fifth chip U5 receives the MA+ and MA- signals with a high level of 5V of the differential input, converts them into IN_MA signals and sends them to the fourth pin of the sixth chip U6. The sixth chip U6 converts the IN_MA signal from a high level of 5V to a high level of 3.3V MCU_MA signal and sends it to the A2 pin of the third chip U3 of the aforementioned signal processing circuit L4 through the third pin.

The third pin of the seventh chip U7 receives the MCU_SLO signal with a high level of 3.3V from the A5 pin of the third chip U3 of the aforementioned signal processing circuit L4, converts it into a high level OUT_SLO signal with a high level of 5V and transmits it to the third pin of the fifth chip U5. The fifth chip U5 converts it into differential signals SLO+ and SLO- for external output.

Specifically, the model of the fifth chip U5 is SN65LBC179; the model of the sixth chip U6 and the seventh chip U7 is SN74LVC1T45DBV; the model of the ninth capacitor C9 is 1UF/16V; the model of the tenth capacitor C10, the eleventh capacitor C11, the thirteenth capacitor C13 and the fourteenth capacitor C14 is 100NF/16V; the model of the twelfth capacitor C12 and the fifteenth capacitor C15 is 50PF/50V; the resistance of the first resistor R1 and the second resistor R2 is 4.7KΩ, the resistance of the third resistor R3 is 10KΩ, and the resistance of the fourth resistor R4 is 120Ω.

In a preferred embodiment, in the signal processing unit 804, the number of rotations of the main gear is calculated by the following formula:

in,

θ1 is the main gear angle;

θ2 is the vernier gear angle;

△θ is the angular difference between the main gear and the vernier gear;

n is the number of teeth on the main gear;

n-1 is the number of teeth of the vernier gear;

x is the number of revolutions of the main gear.

In this embodiment, as shown in FIG8 , the difference in the number of teeth of the two gears is used to make the main gear and the vernier gear at a specific angle combination for different turns, so as to realize the multi-turn counting function of a certain number of turns. For example, if the number of teeth of the main gear is n and the number of teeth of the vernier gear is n-1, then when the main gear rotates one turn, the vernier gear rotates one more turn than the main gear. By analogy, it takes n-1 turns for the angle difference between the two gears to return to the initial position. It can be seen that this method can simply know the number of circles that can be measured by the number of teeth. In this implementation, the number of teeth of the main gear is set to 16, and the number of teeth of the vernier gear is set to 15.

Assuming that the main shaft has rotated X degrees, the current main gear angle θ1 and the vernier gear angle θ2 are as follows:

Where MOD is the remainder function, and the angle difference △θ between the main gear and the vernier gear at any time is:

The angular difference △θ between the main gear and the vernier gear can be obtained as shown in Figure 9.

In addition, we know that for every rotation of the main gear, the cursor gear rotates more than the main gear. cycles. Then in the xth cycle: After transformation, the current number of circles can be calculated as: INT is a floor function. By multiplying the number of turns x by 360, it can be verified that the spindle has rotated X degrees as assumed above, as shown in FIG10 .

Through the above derivation and verification, we can understand the principle of the cursor algorithm and the method of calculating the number of turns. Through this method, we can simply determine the relationship between the number of turns of the product and the number of gear teeth, and produce a multi-turn absolute encoder with fewer and simpler parts.

In production, the accuracy of parts and the progress of sensor chips may affect the number of turns, which may cause errors in the number of turns when switching. This will affect the accuracy of product output. Use the following formula to verify and correct the result of the number of turns calculation.

in,

x’ is the final number of circles obtained after correction;

ROUND is a rounding function.

Through this calibration, an accurate value of the number of turns x’ can be obtained, which enables the product to achieve accurate number of turns measurement without the need for very high part precision.

By extending the vernier gear algorithm, we can get algorithms for multiple vernier gears to achieve counting of more turns. The extended algorithm is as follows:

Let the number of teeth of the main gear be n, the number of teeth of the cursor gear 1 be n-1, and the number of teeth of the cursor gear 2 be n-2. The matching relationship between them is shown in Figure 11, and the cursor gear 1 and the cursor gear 2 are independently meshed with the main gear.

The single-turn tooth difference between the main gear and the vernier gear is The single-turn tooth difference between the main gear and the vernier gear 2 is The single-turn tooth difference between the cursor gear 1 and the cursor gear 2 is The main gear, vernier gear 1 and vernier gear 2 need to go through (n-2)(n-1) cycles to return to the initial angle relationship. When the main gear rotates (n-2)(n-1) cycles, the vernier gear 1 rotates n(n-2) cycles, and the vernier gear 2 rotates n(n-1) cycles.

Using the same method as before, calculate the angle differences △θ1, △θ2, and △θ3 between the main gear and the vernier gear 1, the main gear and the vernier gear 2, and the vernier gear 1 and the vernier gear 2, and graph them as shown in Figure 12. From Figure 12, we can clearly see the cyclic relationship of the angle difference between the gears, but each angle difference has multiple cycles, and the resulting graph is not monotonous and discontinuous. However, by observing the graphs of the angle differences between these gears, we can see that their angle difference relationship is specific at any time. Therefore, in application, by establishing a database of angle relationships, when the angles of the main gear, the vernier gear 1, and the vernier gear 2 are read, the current number of circles can be obtained by looking up the table. Then combine the number of circles information with the angle information of the main gear.

In summary, the vernier gear type magnetic sensitive multi-turn encoder uses a combination of a main gear 4 and a plurality of vernier gears 6, and a certain difference in the number of teeth of the main gear 4 and the number of teeth of the vernier gear 6 is set. The circuit board has a main gear magnetic sensitive chip 81 and a vernier gear magnetic sensitive chip 82, and the main gear magnetic sensitive chip 81 and the vernier gear magnetic sensitive chip 82 are arranged on the same side of the circuit board 8, and are installed facing the main gear magnet 42 and the vernier gear magnet 62. After a certain number of revolutions, the angle of the main gear 4 and the angle of the vernier gear 6 have a specific angle difference. The main gear magnetic sensor chip 81 collects the angle data of the current main gear 4 after a certain number of revolutions relative to the initial angle position, and the vernier gear magnetic sensor chip 82 collects the angle data of the current vernier gear 6 after a certain number of revolutions relative to the initial angle position, and transmits them to the signal processing unit 804 on the circuit board 8 respectively. The signal processing unit 804 calculates the number of revolutions of the current main shaft 2 according to the preset algorithm, and then combines the number of revolutions data and the current angle data of the main shaft 2, that is, the angle data of the current main gear 4, into the final multi-turn absolute position data. The signal processing unit 804 and the differential signal conversion unit 805 convert the multi-turn absolute position data into the required signal mode and output it.

The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. A vernier gear type magnetically sensitive multi-turn encoder, comprising:

The shell is provided with a main shaft through hole, and one side of the main shaft through hole is also provided with a plurality of blind holes;

the cover plate is connected to the shell, and one side of the cover plate is provided with an outlet;

the main shaft penetrates through the main shaft through hole and is arranged in the shell;

the main gear is in pressure connection with one end of the main shaft and is provided with a first magnetic steel mounting hole;

The main gear magnetic steel is arranged in the first magnetic steel mounting hole;

the vernier gear rotating shafts are arranged on one side of the main shaft through the blind holes;

The vernier gears are in pressure connection with one end of the vernier gear rotating shaft, a second magnetic steel mounting hole is formed in the vernier gears, the plurality of vernier gear magnetic steels are respectively mounted in the second magnetic steel mounting hole, and the plurality of vernier gears and the main gear are in independent meshing transmission;

the magnetic isolating sheets are respectively clamped between the main gear and the vernier gear;

The circuit board is arranged on a step in the shell and is positioned between the cover plate and the magnetic isolation sheets, a first magnetic sensitive chip and a plurality of second magnetic sensitive chips are respectively arranged on the same side of the circuit board, the first magnetic sensitive chip is positioned above the main gear magnetic steel and is used for collecting a main gear angle, the second magnetic sensitive chip is positioned above the vernier gear magnetic steel and is used for collecting a vernier gear angle, and the number of main gear rotation turns is calculated according to the main gear angle and the vernier gear angle and corresponding multi-turn absolute position signals are generated;

The circuit board includes:

The voltage conversion unit is used for converting the power supply voltage of an external power supply into the working voltage required by the internal chip included in the circuit board;

the first angle acquisition unit is connected with the voltage conversion unit and is used for acquiring the angle of the main gear and generating a corresponding angle signal of the main gear;

The second angle acquisition unit is connected with the voltage conversion unit and is used for acquiring the angle of the vernier gear and generating a corresponding vernier gear angle signal;

The signal processing unit is respectively connected with the first angle acquisition unit, the second angle acquisition unit and the voltage conversion unit and is used for calculating the rotation number of the main gear according to the angle signal of the main gear and the angle signal of the vernier gear, combining the rotation number of the main gear and the angle of the main gear into multi-turn absolute position data and converting the multi-turn absolute position data into corresponding multi-turn absolute position signals;

the differential signal conversion unit is respectively connected with the voltage conversion unit and the signal processing unit and is used for converting the multi-turn absolute position signal into a differential multi-turn absolute position signal;

in the signal processing unit, the number of rotations of the main gear is calculated by the following formula:

；

Wherein,

-For the main gear angle;

An angle for the cursor gear;

An angle difference between the main gear and the vernier gear;

n is the number of teeth of the main gear;

n-1 is the number of teeth of the vernier gear;

x is the number of rotations of the main gear;

And after the number of rotation turns of the main gear is calculated, executing a verification and correction process for the number of rotation turns of the main gear, wherein the verification and correction process is realized by adopting the following formula:

；

Wherein,

X' is used for indicating the number of rotations of the main gear after the verification and correction process;

ROUND is used to represent the way in which the rounding function is calculated.

2. A vernier gear type magnetic sensitive multi-turn encoder as claimed in claim 1 wherein the main shaft is connected with the housing by a shaft sleeve or a bearing.

3. A vernier gear type magnetic sensitive multi-turn encoder as claimed in claim 1 wherein the cover plate is snap-coupled to the housing.

4. The vernier gear type magnetic sensitive multi-turn encoder as claimed in claim 1, wherein the voltage conversion unit adopts a first chip and a second chip to realize voltage conversion, and a power circuit is further arranged on the circuit board;

The input end of the power supply circuit is connected with the external power supply, and is sequentially connected with a protection fuse, a diode, a TVS diode, the first chip and the second chip;

The anode of the diode is connected with the protection fuse, the cathode of the diode and the cathode of the TVS diode are respectively connected with a first node, and the anode of the TVS diode is grounded;

the first pin of the first chip is respectively connected with one end of a first capacitor and the first node, and the other end of the first capacitor is grounded;

the second pin of the first chip is suspended, and the third pin and the fourth pin are grounded;

The fifth pin of the first chip is connected with one end of a second capacitor, and the other end of the second capacitor is grounded;

the fifth pin of the first chip is a first voltage output end of the power supply circuit;

The first pin of the second chip is respectively connected with one end of a third capacitor and a second node, the other end of the third capacitor is grounded, and the second node is positioned between the cathode of the TVS diode and the first node;

the second pin of the second chip is suspended, and the third pin and the fourth pin are grounded;

the fifth pin of the second chip is connected with one end of a fourth capacitor, and the other end of the fourth capacitor is grounded;

The fifth pin of the second chip is a second voltage output end of the power supply circuit;

the power supply circuit provides two working voltage values for an internal chip included in the circuit board through the first voltage output end and the second voltage output end.

5. The vernier gear type magnetic sensitive multi-turn encoder as claimed in claim 4, wherein the first angle acquisition unit adopts the first magnetic sensitive chip to realize the function of acquiring the angle of the main gear, and a first angle sampling circuit is further arranged on the circuit board, and the vernier gear type magnetic sensitive multi-turn encoder comprises:

the fourth pin of the first magnetosensitive chip is connected with one end of a fifth capacitor, and the other end of the fifth capacitor is grounded;

The fifth pin of the first magnetosensitive chip is a first slave output pin, the sixth pin is a first slave input pin, the seventh pin is a first clock signal pin, and the eighth pin is a first chip selection signal pin;

The ninth pin of the first magnetosensitive chip is respectively connected with the second voltage output end and one end of a sixth capacitor, and the other end of the sixth capacitor is grounded;

an eleventh pin and a twelfth pin of the first magnetosensitive chip are grounded;

The first pin, the second pin, the third pin, the tenth pin, the thirteenth pin, the fourteenth pin, the fifteenth pin and the sixteenth pin of the first magnetosensitive chip are suspended;

The master gear angle acquired by the first angle sampling circuit generates and outputs a corresponding master gear angle signal through a first slave output pin, a first slave input pin, a first clock signal pin and a first slice selection signal pin of the first magnetosensitive chip.

6. The vernier gear type magnetic sensitive multi-turn encoder as claimed in claim 4, wherein the second angle acquisition unit adopts the second magnetic sensitive chip to realize the function of acquiring the vernier gear angle, and a second angle sampling circuit is further arranged on the circuit board, and the second angle sampling circuit comprises:

The fourth pin of the second magnetosensitive chip is connected with one end of a seventh capacitor, and the other end of the seventh capacitor is grounded;

The fifth pin of the second magnetosensitive chip is a second slave output pin, the sixth pin is a second slave input pin, the seventh pin is a second clock signal pin, and the eighth pin is a second chip selection signal pin;

The ninth pin of the second magnetosensitive chip is respectively connected with the second voltage output end and one end of an eighth capacitor, and the other end of the eighth capacitor is grounded;

the eleventh pin and the twelfth pin of the second magnetosensitive chip are grounded;

the first pin, the second pin, the third pin, the tenth pin, the thirteenth pin, the fourteenth pin, the fifteenth pin and the sixteenth pin of the second magnetosensitive chip are suspended;

The vernier gear angle acquired by the second angle sampling circuit generates and outputs corresponding vernier gear angle signals through a second slave output pin, a second slave input pin, a second clock signal pin and a second chip selection signal pin of the second magnetosensitive chip.

7. The vernier gear type magnetic sensitive multi-turn encoder as claimed in claim 4, wherein the signal processing unit adopts a fourth chip to implement the function of calculating the multi-turn absolute position data, and adopts a third chip to implement the function of receiving and converting the main gear angle signal and the vernier gear angle signal, and a signal processing circuit is further provided on the circuit board, comprising:

the twelfth pin of the third chip is connected with the fifth pin of the first magnetosensitive chip, the thirteenth pin is connected with the sixth pin of the first magnetosensitive chip, the fourteenth pin is connected with the seventh pin of the first magnetosensitive chip, the sixteenth pin is connected with the eighth pin of the first magnetosensitive chip, and

A seventeenth pin of the third chip is connected with a fifth pin of the second magnetosensitive chip, an eighteenth pin of the third chip is connected with a sixth pin of the second magnetosensitive chip, a nineteenth pin of the third chip is connected with a seventh pin of the second magnetosensitive chip, and a twenty second pin of the third chip is connected with an eighth pin of the second magnetosensitive chip;

the fourth chip is connected with the third chip and is used for generating corresponding multi-circle absolute position data according to the main gear angle signal and the vernier gear angle signal received by the third chip;

the signal processing circuit converts the multi-turn absolute position data into the multi-turn absolute position signal through the third chip and outputs the multi-turn absolute position signal.

8. The vernier gear type magnetic sensitive multi-turn encoder as claimed in claim 7, wherein the differential signal converting unit employs a fifth chip, a sixth chip and a seventh chip to realize a function of converting the multi-turn absolute position signal into a corresponding differential signal;

the first pin of the fifth chip is connected with one end of a ninth capacitor, and the other end of the ninth capacitor is grounded;

the fourth pin of the fifth chip is grounded;

The seventh pin and the eighth pin of the fifth chip are respectively connected with a differential input signal, and are connected with the fourth pin of the sixth chip through the second pin;

the third pin of the fifth chip is connected with the fourth pin of the sixth chip;

The fifth pin and the sixth pin of the fifth chip respectively output the differential multi-circle absolute position signals;

the first pin of the sixth chip is respectively connected with one end of a tenth capacitor and the second voltage output end, and the other end of the tenth capacitor is grounded;

The sixth pin of the sixth chip is respectively connected with one end of an eleventh capacitor and the first voltage output end, and the other end of the eleventh capacitor is grounded;

the third pin of the sixth chip is respectively connected with the second pin of the third chip, one end of a first resistor and one end of a twelfth capacitor, the other end of the first resistor is connected with the second voltage output end, and the other end of the twelfth capacitor is grounded;

The second pin and the fifth pin of the sixth chip are grounded;

the sixth chip performs level conversion on the differential input signal and inputs the differential input signal to the third chip;

The first pin of the seventh chip is respectively connected with one end of a thirteenth capacitor and the second voltage output end, and the other end of the thirteenth capacitor is grounded;

The sixth pin of the seventh chip is respectively connected with one end of a fourteenth capacitor and the first voltage output end, and the other end of the fourteenth capacitor is grounded;

The third pin of the seventh chip is respectively connected with the fourth pin of the third chip, one end of a second resistor and one end of a fifteenth capacitor, the other end of the second resistor is connected with the second voltage output end, and the other end of the fifteenth capacitor is grounded;

the fifth pin of the seventh chip is connected with one end of a third resistor, and the other end of the third resistor is connected with the second voltage output end;

The second pin of the seventh chip is grounded;

the seventh chip performs level conversion on the multi-turn absolute position signal containing the differential input signal and outputs the multi-turn absolute position signal to a fifth chip;

The differential signal conversion unit is used for converting the single-ended multi-turn absolute position signal into a differential multi-turn absolute position signal.