A self-resetting non-contact potentiometer and its control method

Abstract

This invention relates to the field of potentiometer technology, specifically to a self-resetting non-contact potentiometer and its control method. The potentiometer includes: a sensor circuit that outputs an incremental signal based on position change sensing information from a sensor chip; a control circuit connected to the sensor circuit that receives the incremental signal and converts it into a modulation signal for output via a control chip; and a conversion circuit connected to the control circuit that receives the modulation signal via a conversion chip and linearly converts it into a corresponding analog quantity output based on the duty cycle of the modulation signal. This invention provides a non-contact potentiometer that can output an analog quantity proportional to position information, and when the potentiometer is powered on again, the output is the initial output rather than the output before power loss, thus achieving a self-resetting function.

Description

Technical Field

[0001] This invention relates to the field of potentiometer technology, and more specifically to a non-contact potentiometer and its control method. Background Technology

[0002] As an upgraded replacement for resistive potentiometers, non-contact potentiometers are increasingly widely used in industrial control, instrumentation, vehicles, ships and other fields. Compared with resistive potentiometers, non-contact potentiometers have a longer lifespan, better temperature characteristics and no electrical noise.

[0003] Non-contact potentiometers typically output analog signals. In existing technologies, when a potentiometer is powered on again after a power outage, the output is the same as before the power outage, rather than the initial output. Therefore, in some special applications, if the device immediately enters the high-speed operating state before the power outage upon power-on, it may pose certain safety hazards. Summary of the Invention

[0004] The purpose of this invention is to provide a self-resetting non-contact potentiometer to solve the above-mentioned technical problems;

[0005] The present invention also aims to provide a control method for a self-resetting non-contact potentiometer, thereby solving the above-mentioned technical problems.

[0006] The technical problem solved by this invention can be achieved by the following technical solutions:

[0007] A self-resetting non-contact potentiometer, comprising:

[0008] The sensor circuit outputs an incremental signal based on the position change sensing information of a sensor chip (U1);

[0009] The control circuit is connected to the sensor circuit to receive the incremental signal, and converts the incremental signal into a modulation signal for output through a control chip (U2);

[0010] The conversion circuit, connected to the control circuit, receives the modulation signal through a conversion chip (U3) and linearly converts it into a corresponding analog output based on the duty cycle of the modulation signal.

[0011] Preferably, the sensor circuit includes,

[0012] The power supply terminal (U1_VDD) of the sensor chip (U1) is connected to the first input voltage (VC1) through a first resistor (R1);

[0013] The second resistor (R2) is used to connect the first signal output terminal of the sensor chip (U1) to the first signal receiving terminal (U2_PA0) of the control chip (U2).

[0014] The third resistor (R3) is used to connect the second signal output terminal of the sensor chip (U1) to the second signal receiving terminal (U2_PA1) of the control chip (U2);

[0015] The fourth resistor (R4) is connected to the ground after the operating mode terminal (U1_MODE) of the sensor chip (U1) is connected to the fourth resistor (R4);

[0016] The first capacitor (C1) has its first end connected to the power supply terminal (U1_VDD) of the sensor chip (U1), and its second end connected to the ground terminal (U1_GND) of the sensor chip (U1) and grounded.

[0017] Preferably, the first resistor (R1), the second resistor (R2), the third resistor (R3), and the fourth resistor (R4) are all 0-ohm resistors.

[0018] Preferably, the control circuit includes,

[0019] The control chip (U2) has its signal output terminal (U2_PB6) connected to a conversion chip (U3) for outputting the modulation signal, and its power supply terminal (U2_VDD) connected to the first input voltage (VC1).

[0020] A crystal oscillator (Y1) is provided. The first end of the crystal oscillator (Y1) is connected to the first clock terminal (U2_PD0) of the control chip (U2). The third end of the crystal oscillator (Y1) is connected to the second clock terminal (U2_PD1) of the control chip (U2). The second end and the fourth end of the crystal oscillator (Y1) are grounded respectively.

[0021] The second capacitor (C2) has its first terminal connected to the first terminal of the crystal oscillator (Y1), and its second terminal connected to the second terminal of the crystal oscillator (Y1).

[0022] The third capacitor (C3) has its first terminal connected to the second terminal of the crystal oscillator (Y1), and its second terminal connected to the third terminal of the crystal oscillator (Y1).

[0023] The fifth resistor (R5) has its first end connected to the first end of the crystal oscillator (Y1) and its second end connected to the third end of the crystal oscillator (Y1).

[0024] Preferably, the control circuit further includes,

[0025] The sixth resistor (R6) has its first end connected to the first input voltage (VC1), and its second end connected to the reset terminal (U2_NRST) of the control chip (U2).

[0026] The fourth capacitor (C4) has its first terminal connected to the reset terminal (U2_NRST) of the control chip (U2), and its second terminal grounded.

[0027] The seventh resistor (R7) is connected to the flash memory terminal (U2_BOOT0) of the control chip (U2) and then grounded.

[0028] The first inductor (L1) has its first end connected to the first input voltage (VC1) and its second end connected to the operating voltage terminal (U2_VDDA) of the control chip (U2).

[0029] The fifth capacitor (C5) has its first terminal connected to the first input voltage (VC1) and its second terminal grounded.

[0030] A sixth capacitor (C6) is provided, wherein the first terminal of the sixth capacitor (C6) is connected to the first terminal of the fifth capacitor (C5), and the second terminal of the sixth capacitor (C6) is connected to the second terminal of the fifth capacitor (C5).

[0031] A seventh capacitor (C7) is provided, wherein the first terminal of the seventh capacitor (C7) is connected to the first terminal of the sixth capacitor (C6), and the second terminal of the seventh capacitor (C7) is connected to the second terminal of the sixth capacitor (C6).

[0032] The eighth capacitor (C8) has its first terminal connected to the first input voltage (VC1) and its second terminal grounded.

[0033] A ninth capacitor (C9) is provided, wherein the first terminal of the ninth capacitor (C9) is connected to the first terminal of the eighth capacitor (C8), and the second terminal of the ninth capacitor (C9) is connected to the second terminal of the eighth capacitor (C8).

[0034] Preferably, the conversion circuit includes,

[0035] The conversion chip (U3) has its signal receiving terminal (U3_PWM) connected to the signal output terminal (U2_PB6) of the control chip (U2) for receiving the modulation signal. The output terminal (U3_VOUT) of the conversion chip (U3) outputs the analog quantity. The power supply terminal of the conversion chip (U3) is connected to a second input voltage (VC2).

[0036] The tenth capacitor (C10) has its first terminal connected to the first selection signal terminal (U3_SEL) and the second selection signal terminal of the conversion chip (U3), and its second terminal grounded.

[0037] The eleventh capacitor (C11) has its first terminal connected to the power supply terminal of the conversion chip (U3), and its second terminal grounded.

[0038] The twelfth capacitor (C12) has its first end connected to the output terminal (U3_VOUT) of the conversion chip (U3), and its second end connected to the ground terminal (U3_GND) of the conversion chip (U3).

[0039] The first diode (D1) is connected to the second terminal of the twelfth capacitor (C12), and the negative terminal of the first diode (D1) is connected to the second terminal of the twelfth capacitor (C12).

[0040] Preferably, it further includes a power supply circuit, said power supply circuit comprising,

[0041] The first linear regulator (U4) has its input terminal (U4_IN) connected to an external power supply voltage via a second diode (D2). The negative terminal of the second diode (D2) is connected to the input terminal (U4_IN) of the first linear regulator (U4), and the positive terminal of the second diode (D2) is connected to the power supply voltage VCC. The output terminal (U4_OUT) of the first linear regulator (U4) outputs the second input voltage (VC2).

[0042] The thirteenth capacitor (C13) has its first terminal connected to the input terminal (U4_IN) of the first linear regulator (U4), and its second terminal grounded.

[0043] The third diode (D3) has its negative terminal connected to the first terminal of the thirteenth capacitor (C13), and its positive terminal connected to the second terminal of the thirteenth capacitor (C13).

[0044] The eighth resistor (R8) has its first end connected to the voltage regulation terminal (U4_ADJ) of the first linear regulator (U4);

[0045] The ninth resistor (R9) has its first end connected to the second end of the eighth resistor (R8), and its second end grounded.

[0046] The tenth resistor (R10) has its first end connected to the output terminal (U4_OUT) of the first linear regulator (U4), and its second end connected to the voltage regulation terminal (U4_ADJ) of the first linear regulator (U4).

[0047] The fourteenth capacitor (C14) has its first terminal connected to the output terminal (U4_OUT) of the first linear regulator (U4), and its second terminal grounded.

[0048] Preferably, the power supply circuit further includes

[0049] The second linear regulator (U5) has its input terminal (U5_VIN) connected to the output terminal (U4_OUT) of the first linear regulator (U4) to receive the second input voltage (VC2). The output terminal (U5_VOUT) of the second linear regulator (U5) outputs the first input voltage (VC1). The ground terminal (U5_GND) of the second linear regulator (U5) is grounded.

[0050] The fifteenth capacitor (C15) has its first end connected to the output terminal (U5_VOUT) of the second linear regulator (U5), and its second end connected to the ground terminal (U5_GND) of the second linear regulator (U5).

[0051] A control method for a self-resetting non-contact potentiometer, applied to the self-resetting non-contact potentiometer, includes,

[0052] Step S1: The sensor circuit outputs the incremental signal based on the position change sensing information fed back by the sensor chip (U1);

[0053] In step S2, the control circuit receives the incremental signal and converts the incremental signal into the modulation signal for output through the control chip (U2);

[0054] In step S3, the conversion circuit receives the modulation signal through the conversion chip (U3) and linearly converts it into the analog output based on the duty cycle of the modulation signal.

[0055] Preferably, in step S2, the incremental signal includes a counting incremental pulse of the first phase and a directional incremental pulse of the second phase. The control chip (U2) acquires the incremental signal in an orthogonal encoding manner through the first timer channel. The control chip (U2) converts the incremental signal acquired by the first timer channel into the modulation signal and outputs it through the second timer channel.

[0056] The beneficial effects of the present invention are as follows: By adopting the above technical solution, the present invention provides a non-contact potentiometer that can output an analog quantity proportional to the position information. When the potentiometer is powered on again, the output is the initial output rather than the output before the power failure, thus realizing the self-reset function. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the sensor circuit structure in an embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram of the control circuit structure in an embodiment of the present invention;

[0059] Figure 3 This is a schematic diagram of the reset terminal connection of the control chip in an embodiment of the present invention;

[0060] Figure 4 This is a schematic diagram showing the connection of the fifth, sixth, and seventh capacitors in an embodiment of the present invention;

[0061] Figure 5 This is a schematic diagram showing the connection between the eighth and ninth capacitors in an embodiment of the present invention;

[0062] Figure 6 This is a schematic diagram of the conversion circuit structure in an embodiment of the present invention;

[0063] Figure 7 This is a schematic diagram of the connection of the first linear regulator in an embodiment of the present invention;

[0064] Figure 8 This is a schematic diagram of the connection of the second linear regulator in an embodiment of the present invention;

[0065] Figure 9 This is a schematic diagram of the steps of the potentiometer control method in an embodiment of the present invention;

[0066] Figure 10 This is a flowchart of the potentiometer control method in an embodiment of the present invention;

[0067] Figure 11 This is a flowchart illustrating the operation of the control chip in an embodiment of the present invention.

[0068] Figure 12 This is a flowchart of the circle count calculation in an embodiment of the present invention;

[0069] Figure 13 This is a flowchart illustrating the calculation of the duty cycle value in an embodiment of the present invention. Detailed Implementation

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0072] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0073] A self-resetting non-contact potentiometer, such as Figures 1 to 9 As shown, including,

[0074] The sensor circuit outputs an incremental signal based on the position change sensing information of a sensor chip U1.

[0075] The control circuit is connected to the sensor circuit to receive incremental signals, and converts the incremental signals into modulated signals for output through a control chip U2.

[0076] The conversion circuit, connected to the control circuit, receives the modulation signal through a conversion chip U3 and linearly converts it into a corresponding analog output based on the duty cycle of the modulation signal.

[0077] Specifically, the present invention provides a self-resetting non-contact potentiometer that can output an analog control signal proportional to the position information of the sensor chip U1. By adopting a non-contact solution, the service life of the potentiometer can be extended. The present invention transmits an incremental signal that is only related to the position change of the sensor chip U1. Therefore, after a power failure, the output is the initial output when the power is restored instead of the output before the power failure, thus achieving the self-resetting function.

[0078] In a preferred embodiment, such as Figure 1 As shown, the sensor circuit includes,

[0079] Sensor chip U1, the power supply terminal U1_VDD of sensor chip U1 is connected to the first input voltage VC1 through a first resistor R1;

[0080] The second resistor R2 connects the first signal output terminal U1_A of the sensor chip U1 to the first signal receiving terminal U2_PA0 of the control chip U2.

[0081] The third resistor R3 connects the second signal output terminal U1_B of sensor chip U1 to the second signal receiving terminal U2_PA1 of control chip U2 through the third resistor R3.

[0082] The fourth resistor R4 is connected to the U1_MODE terminal of the sensor chip U1 and then grounded.

[0083] The first capacitor C1 has its first end connected to the power supply terminal U1_VDD of the sensor chip U1, and its second end connected to the ground terminal U1_GND of the sensor chip U1 and grounded. Specifically, in this embodiment, the capacitance of the first capacitor is 100nF.

[0084] Specifically, the sensor circuit can realize the output of incremental signals by feeding back position change information through sensor chip U1. The incremental signals include the counting incremental pulse of the first phase and the direction incremental pulse of the second phase. Since the output is an incremental pulse signal, the potentiometer can realize the self-reset function.

[0085] Specifically, the sensor chip U1 of this invention uses a Hall effect chip of model MT6701. When the magnetic field placed directly above the sensor chip U1 changes, the sensor chip U1 can analyze the changes on the X and Y axes and output incremental signals to the control chip U2 for processing. Because the output is an incremental signal, it supports self-reset. The incremental signal can be freely programmed and output in the range of 1-1024. The first capacitor C1 is the filter capacitor for the power supply terminal U1_VDD of the sensor chip U1.

[0086] In a preferred embodiment, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are all 0-ohm resistors; specifically, the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are used for the connection of the circuit after the sensor chip U1 is programmed.

[0087] In a preferred embodiment, such as Figures 2 to 5 As shown, the control circuit includes,

[0088] The control chip U2 has its signal output terminal U2_PB6 connected to the conversion chip U3 for outputting a modulated signal. The power supply terminal U2_VDD of the control chip U2 is connected to the first input voltage VC1.

[0089] Crystal oscillator Y1, the first terminal of crystal oscillator Y1 is connected to the first clock terminal U2_PD0 of control chip U2, the third terminal of crystal oscillator Y1 is connected to the second clock terminal U2_PD1 of control chip U2, and the second terminal and the fourth terminal of crystal oscillator Y1 are grounded respectively;

[0090] The second capacitor C2 has its first terminal connected to the first terminal of the crystal oscillator Y1, and its second terminal connected to the second terminal of the crystal oscillator Y1. Specifically, in this embodiment, the capacitance of the second capacitor C2 is 20pF.

[0091] The third capacitor C3 has its first terminal connected to the second terminal of the crystal oscillator Y1, and its second terminal connected to the third terminal of the crystal oscillator Y1. Specifically, in this embodiment, the capacitance of the third capacitor C3 is 20pF.

[0092] The fifth resistor R5 has its first end connected to the first end of the crystal oscillator Y1, and its second end connected to the third end of the crystal oscillator Y1. Specifically, in this embodiment, the resistance of the fifth resistor R5 is 1MΩ.

[0093] Specifically, the output incremental signal is acquired and identified by the first timer channel of the control chip U2 using orthogonal encoding, including the counting incremental pulse of the first phase and the direction incremental pulse of the second phase. The control chip U2 uses an STM32F103C8T6 microcontroller, and the modulation signal is a PWM modulation signal. The control chip U2 converts the pulse count and direction value read by the first timer channel into the duty cycle value of the PWM modulation signal, and the second timer signal of the control chip U2 outputs the PWM modulation signal.

[0094] Furthermore, the control chip U2 uses an external 8MHz crystal oscillator Y1. The control chip U2 processes the received incremental signal and outputs a PWM modulation signal to the conversion chip U3.

[0095] In a preferred embodiment, the control circuit further includes,

[0096] The sixth resistor R6 has its first end connected to the first input voltage VC1, and its second end connected to the reset terminal U2_NRST of the control chip U2. Specifically, in this embodiment, the resistance of the sixth resistor R6 is 10kΩ.

[0097] The fourth capacitor C4 has its first terminal connected to the reset terminal U2_NRST of the control chip U2, and its second terminal grounded. Specifically, in this embodiment, the capacitance of the fourth capacitor C4 is 100nF.

[0098] The seventh resistor R7 is connected to the flash memory terminal U2_BOOT0 of the control chip U2 and then grounded; specifically, in this embodiment, the resistance value of the seventh resistor R7 is 100kΩ.

[0099] The first inductor L1 has its first end connected to the first input voltage VC1, and its second end connected to the operating voltage terminal U2_VDDA of the control chip U2.

[0100] The fifth capacitor C5 has its first terminal connected to the first input voltage VC1, and its second terminal grounded. Specifically, in this embodiment, the capacitance of the fifth capacitor C5 is 100nF.

[0101] The sixth capacitor C6 has its first terminal connected to the first terminal of the fifth capacitor C5, and its second terminal connected to the second terminal of the fifth capacitor C5. Specifically, in this embodiment, the capacitance of the sixth capacitor C6 is 100nF.

[0102] The seventh capacitor C7 has its first terminal connected to the first terminal of the sixth capacitor C6, and its second terminal connected to the second terminal of the sixth capacitor C6. Specifically, in this embodiment, the capacitance of the seventh capacitor C7 is 100nF.

[0103] The eighth capacitor C8 has its first terminal connected to the first input voltage VC1 and its second terminal grounded. Specifically, in this embodiment, the capacitance of the eighth capacitor C8 is 100nF.

[0104] The ninth capacitor C9 has its first terminal connected to the first terminal of the eighth capacitor C8, and its second terminal connected to the second terminal of the eighth capacitor C8. Specifically, in this embodiment, the capacitance of the ninth capacitor C9 is 100nF.

[0105] In a preferred embodiment, such as Figure 6 As shown, the conversion circuit includes,

[0106] The signal receiving terminal U3_PWM of the conversion chip U3 is connected to the signal output terminal U2_PB6 of the control chip U2 to receive the modulation signal. The output terminal U3_VOUT of the conversion chip U3 outputs an analog signal. The power supply terminal U3_VCC of the conversion chip U3 is connected to a second input voltage VC2.

[0107] The tenth capacitor C10 has its first terminal connected to the first selection signal terminal U3_SEL and the second selection signal terminal U3_V5V of the conversion chip U3, and its second terminal grounded. Specifically, in this embodiment, the capacitance of the tenth capacitor C10 is 1uF.

[0108] The eleventh capacitor C11 has its first terminal connected to the power supply terminal U3_VCC of the conversion chip U3, and its second terminal grounded. Specifically, in this embodiment, the capacitance of the eleventh capacitor C11 is 1uF.

[0109] The twelfth capacitor C12 has its first terminal connected to the output terminal U3_VOUT of the conversion chip U3, and its second terminal connected to the ground terminal U3_GND of the conversion chip U3. Specifically, in this embodiment, the capacitance of the twelfth capacitor C12 is 10uF.

[0110] The first diode D1 has its anode connected to the second terminal of the twelfth capacitor C12, and its cathode connected to the second terminal of the twelfth capacitor C12.

[0111] Specifically, the analog quantity output by this invention is either a voltage analog quantity or a current analog quantity. In this embodiment, the conversion chip U3 adopts the GP8101-F50-NH-SW model conversion chip, which outputs the corresponding voltage analog quantity according to the PWM modulation signal output by the control chip U2. Since the first selection signal terminal U3_SEL and the second selection signal terminal U3_V5V of the conversion chip U3 are connected, it can output a voltage analog quantity in the range of 0V-10V. The voltage value is linearly related to the duty cycle value of the PWM. Furthermore, the conversion chip U3 can also be a current conversion chip, which outputs the corresponding current analog quantity according to the PWM modulation signal output by the control chip U2.

[0112] Furthermore, the eleventh capacitor C11 is the filter capacitor for the power supply terminal U3_VCC of the conversion chip U3, the tenth capacitor C10 is the filter capacitor for the internal voltage regulator of the conversion chip U3, and the twelfth capacitor C12 is the load capacitor for the output terminal U3_VOUT of the conversion chip U3, which makes the output smoother. At the same time, the first diode D1 is added at the output terminal as an overvoltage protection device, which can protect against reverse overvoltage.

[0113] In a preferred embodiment, a power supply circuit is further included, the power supply circuit comprising,

[0114] The first linear regulator U4 has its input terminal U4_IN connected to the external power supply voltage through a second diode D2. The negative terminal of the second diode D2 is connected to the input terminal U4_IN of the first linear regulator U4, and the positive terminal of the second diode D2 is connected to the power supply voltage VCC. The output terminal U4_OUT of the first linear regulator U4 outputs the second input voltage VC2.

[0115] The thirteenth capacitor C13 has its first terminal connected to the input terminal U4_IN of the first linear regulator U4, and its second terminal grounded. Specifically, in this embodiment, the capacitance of the thirteenth capacitor C13 is 100nF.

[0116] The third diode D3 has its negative terminal connected to the first terminal of the thirteenth capacitor C13, and its positive terminal connected to the second terminal of the thirteenth capacitor C13.

[0117] The eighth resistor R8 has its first terminal connected to the voltage regulation terminal U4_ADJ of the first linear regulator U4.

[0118] The ninth resistor R9 has its first terminal connected to the second terminal of the eighth resistor R8, and its second terminal is grounded.

[0119] The tenth resistor R10 has its first end connected to the output terminal U4_OUT of the first linear regulator U4, and its second end connected to the voltage adjustment terminal U4_ADJ of the first linear regulator U4.

[0120] The fourteenth capacitor C14 has its first terminal connected to the output terminal U4_OUT of the first linear regulator U4, and its second terminal grounded.

[0121] In a preferred embodiment, such as Figure 7 , Figure 8 As shown, the power supply circuit also includes,

[0122] The second linear regulator U5 has its input terminal U5_VIN connected to the output terminal U4_OUT of the first linear regulator U4 to receive the second input voltage VC2. The output terminal U5_VOUT of the second linear regulator U5 outputs the first input voltage VC1. The ground terminal U5_GND of the second linear regulator U5 is grounded.

[0123] The fifteenth capacitor C15 has its first terminal connected to the output terminal U5_VOUT of the second linear regulator U5, and its second terminal connected to the ground terminal of the second linear regulator U5.

[0124] Specifically, the external power supply voltage VCC can be a wide voltage range, such as 15V-30V. This invention provides a first input voltage VC1 of 3.3V and a second input voltage VC2 of 12V through a power supply circuit. The second diode D2 is used for reverse connection protection, and the third diode D3 is an overvoltage protection device. By adjusting the eighth resistor R8, the ninth resistor R9, and the tenth resistor R10, the output terminal U4_OUT of the first linear regulator U4 is regulated to 12V. The thirteenth capacitor C13 and the fourteenth capacitor C14 are the input and output filter capacitors of the first linear regulator U4, respectively. The second input voltage VC2 of 12V output from the first linear regulator U4 supplies power to the second linear regulator U5 and the conversion chip U3, respectively. The second linear regulator U5 is used to regulate the first input voltage VC1 to 3.3V and supplies power to the sensor chip U1 and the control chip U2, respectively. The fifteenth capacitor C15 is the output filter capacitor of the second linear regulator U5, making the output of the second linear regulator U5 smoother.

[0125] A control method for a self-resetting non-contact potentiometer, applicable to the self-resetting non-contact potentiometer in any of the embodiments, such as... Figure 9 , Figure 10 As shown, including,

[0126] Step S1: The sensor circuit outputs an incremental signal based on the position change sensing information fed back by the sensor chip U1.

[0127] In step S2, the control circuit receives the incremental signal and converts it into a modulated signal for output through the control chip U2.

[0128] In step S3, the conversion circuit receives the modulation signal through the conversion chip U3 and linearly converts it into an analog output based on the duty cycle of the modulation signal.

[0129] In a preferred embodiment, in step S2, the incremental signal includes the counting incremental pulse of the first phase and the direction incremental pulse of the second phase. The control chip U2 acquires the incremental signal through the first timer channel in an orthogonal encoding manner. The control chip U2 converts the incremental signal acquired by the first timer channel into a modulation signal and outputs it through the second timer channel.

[0130] Specifically, such as Figure 11 As shown, the control chip U2 of this invention uses the FreeRTOS multitasking operating system to create two tasks, including Task 1: reading the pulse count and direction value of the first timer channel; Task 2: calculating the duty cycle of the PWM modulation signal based on the read pulse count and direction value; performing task scheduling and executing the task loop.

[0131] Furthermore, such as Figure 12As shown, the first timer channel is initialized to interrupt mode. After startup, it can automatically acquire incremental signals without interference. This invention sets the number of pulses output per rotation. The reading is performed within the pulse count period of each rotation. When the reading count reaches one pulse count period, it is determined that one rotation has been completed, and the data is cleared and reading is restarted. Based on the direction value of the incremental signal, it is determined whether the direction value is positive or negative, and the number of rotations of the sensor chip U1 is calculated based on the direction value. This process is repeated.

[0132] Furthermore, such as Figure 13 As shown, in Task 1, the collected pulse count and direction values ​​are processed and converted into duty cycle values. The duty cycle value of the second timer channel is set to output the PWM modulation signal. The specific calculation formula is P_SUM=R×P+P_NUM; and ARR=P_SUM / P_SET×100%.

[0133] In the formula: R is the number of revolutions, P is the number of pulses per revolution, P_NUM is the number of pulses read in the current pulse count cycle, P_SUM is the total number of pulses, P_SET is the preset pulse parameter, and ARR is the duty cycle value.

[0134] In summary, this invention provides a self-resetting non-contact potentiometer and a control method for the potentiometer. Its technical advantages are: first, it can output an analog control signal proportional to the position information; second, after a power outage, the output is the initial output when power is restored, rather than the output before the power outage, thus realizing the self-resetting function; third, the electrical design uses non-contact technology, resulting in a long product lifespan.

[0135] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-resetting non-contact potentiometer, characterized in that, include, The sensor circuit outputs an incremental signal based on the position change sensing information of a sensor chip U1. The control circuit is connected to the sensor circuit to receive the incremental signal, and converts the incremental signal into a modulation signal for output through a control chip U2; The conversion circuit is connected to the control circuit. It receives the modulation signal through a conversion chip U3 and linearly converts it into a corresponding analog output based on the duty cycle of the modulation signal. The sensor circuit includes, The power supply terminal U1_VDD of the sensor chip U1 is connected to the first input voltage VC1 through a first resistor R1; The second resistor R2 connects the first signal output terminal of the sensor chip U1 to the first signal receiving terminal U2_PA0 of the control chip U2 through the second resistor R2. The third resistor R3 connects the second signal output terminal of the sensor chip U1 to the second signal receiving terminal U2_PA1 of the control chip U2 through the third resistor R3. The fourth resistor R4 is connected to the working mode terminal U1_MODE of the sensor chip U1 and then grounded. The first capacitor C1 has its first end connected to the power supply terminal U1_VDD of the sensor chip U1, and its second end connected to the ground terminal U1_GND of the sensor chip U1 and grounded.

2. The self-resetting non-contact potentiometer according to claim 1, characterized in that, The first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are all 0-ohm resistors.

3. The self-resetting non-contact potentiometer according to claim 1, characterized in that, The control circuit includes, The control chip U2 has a signal output terminal U2_PB6 connected to a conversion chip U3 for outputting the modulation signal, and the power supply terminal U2_VDD of the control chip U2 is connected to the first input voltage VC1. Crystal oscillator Y1, the first end of which is connected to the first clock terminal U2_PD0 of the control chip U2, the third end of which is connected to the second clock terminal U2_PD1 of the control chip U2, and the second and fourth ends of which are grounded respectively; The second capacitor C2 has its first terminal connected to the first terminal of the crystal oscillator Y1, and its second terminal connected to the second terminal of the crystal oscillator Y1. The third capacitor C3 has its first terminal connected to the second terminal of the crystal oscillator Y1, and its second terminal connected to the third terminal of the crystal oscillator Y1. The fifth resistor R5 has its first end connected to the first end of the crystal oscillator Y1, and its second end connected to the third end of the crystal oscillator Y1.

4. The self-resetting non-contact potentiometer according to claim 3, characterized in that, The control circuit also includes, The sixth resistor R6 has its first end connected to the first input voltage VC1, and its second end connected to the reset terminal U2_NRST of the control chip U2. The fourth capacitor C4 has its first end connected to the reset terminal U2_NRST of the control chip U2, and its second end grounded. The seventh resistor R7 is connected to the flash memory terminal U2_BOOT0 of the control chip U2 and then grounded. A first inductor L1, the first end of the first inductor L1 is connected to the first input voltage VC1, and the second end of the first inductor L1 is connected to the working voltage terminal U2_VDDA of the control chip U2. The fifth capacitor C5 has its first terminal connected to the first input voltage VC1 and its second terminal grounded. A sixth capacitor C6, the first end of which is connected to the first end of the fifth capacitor C5, and the second end of which is connected to the second end of the fifth capacitor C5; The seventh capacitor C7 has its first terminal connected to the first terminal of the sixth capacitor C6, and its second terminal connected to the second terminal of the sixth capacitor C6. The eighth capacitor C8 has its first terminal connected to the first input voltage VC1 and its second terminal grounded. The ninth capacitor C9 has its first terminal connected to the first terminal of the eighth capacitor C8, and its second terminal connected to the second terminal of the eighth capacitor C8.

5. The self-resetting non-contact potentiometer according to claim 1, characterized in that, The conversion circuit includes, The conversion chip U3 has a signal receiving terminal U3_PWM connected to the signal output terminal U2_PB6 of the control chip U2 for receiving the modulation signal. The output terminal U3_VOUT of the conversion chip U3 outputs the analog quantity. The power supply terminal of the conversion chip U3 is connected to a second input voltage VC2. The tenth capacitor C10 has its first terminal connected to the first selection signal terminal U3_SEL and the second selection signal terminal of the conversion chip U3, and its second terminal grounded. The eleventh capacitor C11 has its first terminal connected to the power supply terminal of the conversion chip U3, and its second terminal grounded. The twelfth capacitor C12 has its first end connected to the output terminal U3_VOUT of the conversion chip U3, and its second end connected to the ground terminal U3_GND of the conversion chip U3. A first diode D1 is connected to the second terminal of the twelfth capacitor C12, and the negative terminal of the first diode D1 is connected to the second terminal of the twelfth capacitor C12.

6. The self-resetting non-contact potentiometer according to claim 5, characterized in that, It also includes a power supply circuit, said power supply circuit comprising, The first linear regulator U4 has its input terminal U4_IN connected to the external power supply voltage through a second diode D2. The negative terminal of the second diode D2 is connected to the input terminal U4_IN of the first linear regulator U4, and the positive terminal of the second diode D2 is connected to the power supply voltage VCC. The output terminal U4_OUT of the first linear regulator U4 outputs the second input voltage VC2. The thirteenth capacitor C13 has its first terminal connected to the input terminal U4_IN of the first linear regulator U4, and its second terminal grounded. The third diode D3, the negative terminal of the third diode D3 is connected to the first terminal of the thirteenth capacitor C13, and the positive terminal of the third diode D3 is connected to the second terminal of the thirteenth capacitor C13; The eighth resistor R8, the first end of which is connected to the voltage regulation terminal U4_ADJ of the first linear regulator U4; The ninth resistor R9 has its first end connected to the second end of the eighth resistor R8, and its second end grounded. The tenth resistor R10 has its first end connected to the output terminal U4_OUT of the first linear regulator U4, and its second end connected to the voltage regulation terminal U4_ADJ of the first linear regulator U4. The fourteenth capacitor C14 has its first terminal connected to the output terminal U4_OUT of the first linear regulator U4, and its second terminal grounded.

7. The self-resetting non-contact potentiometer according to claim 6, characterized in that, The power supply circuit also includes The second linear regulator U5 has its input terminal U5_VIN connected to the output terminal U4_OUT of the first linear regulator U4 to receive the second input voltage VC2. The output terminal U5_VOUT of the second linear regulator U5 outputs the first input voltage VC1. The ground terminal U5_GND of the second linear regulator U5 is grounded. The fifteenth capacitor C15 has its first end connected to the output terminal U5_VOUT of the second linear regulator U5, and its second end connected to the ground terminal U5_GND of the second linear regulator U5.

8. A control method for a self-resetting non-contact potentiometer, applied to the self-resetting non-contact potentiometer as described in any one of claims 1-7, characterized in that, include, Step S1: The sensor circuit outputs the incremental signal based on the position change sensing information fed back by the sensor chip U1. In step S2, the control circuit receives the incremental signal and converts the incremental signal into the modulation signal for output through the control chip U2; In step S3, the conversion circuit receives the modulation signal through the conversion chip U3 and linearly converts it into the analog output based on the duty cycle of the modulation signal.

9. The control method for a self-resetting non-contact potentiometer according to claim 8, characterized in that, In step S2, the incremental signal includes the counting incremental pulse of the first phase and the direction incremental pulse of the second phase. The control chip U2 acquires the incremental signal in an orthogonal encoding manner through the first timer channel. The control chip U2 converts the incremental signal acquired by the first timer channel into the modulation signal and outputs it through the second timer channel.

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