Transmission circuit for steering and rotating speed signals of three-wire direct current motor

Abstract

The invention discloses a transmission circuit and a transmission method for steering and rotating speed signals of a three-wire direct current motor, and the circuit comprises a motor power supply positive electrode end, a motor speed regulation negative electrode end, a grounding transmission end and a Hall sensor, the motor power supply positive electrode end and the motor speed regulation negative electrode end are electrically connected with a Hall positive voltage end through a rectification filter circuit and a voltage stabilizing circuit; the grounding transmission end is electrically connected with the Hall grounding end; and the direction and speed signal output pin is electrically connected with the Hall grounding end through the signal superposition circuit, so that a direction signal and a speed signal generated by the Hall sensor are superposed with quiescent currents of the voltage stabilizing circuit and the Hall sensor and are transmitted out through the grounding transmission end. On the basis of three wires of an original direct current motor, two wires are used for supplying power to the motor and the Hall sensor, and the other wire can be used for transmitting a direction signal, a speed signal and a quiescent current of the Hall sensor and a quiescent current of a voltage stabilizing circuit besides being used for anti-interference grounding.

Description

[0001] Divisional application, original case application number: 202111302184.3, application date: November 4, 2021; invention name: a transmission circuit of three-wire DC motor steering and rotating speed signal and its transmission method. TECHNICAL FIELD

[0002] The present application relates to a DC motor control circuit, in particular to a transmission circuit of three-wire DC motor steering and rotating speed signal and its transmission method. BACKGROUND

[0003] The existing motor line of the DC courtyard door opener is generally a 3-core cable, which is ① positive power line, ② PWM speed negative line, and ③ anti-interference ground line. If the control system needs to control the motor more accurately, it needs to increase the Hall to feedback the actual rotating speed and steering signal of the motor, and needs to increase the wiring of the Hall alone. For the Hall with direction signal, generally 4 lines are added. They are ① positive power line, ② negative power line, ③ direction signal line, and ④ speed signal line. In this way, the motor lead of the door opener will increase to 7. This is quite unfavorable for the sales of courtyard doors. Because most of the pre-buried cables of courtyard doors are 3-core, which means that the installation of 7-wire motor needs to be re-wired. For users who have pre-buried 3-wire or replace old models, they may need to re-dig and bury wires, which increases the installation workload, installation cost and cable cost. SUMMARY

[0004] An object of the present application is to provide a transmission circuit of three-wire DC motor steering and rotating speed signal with simple and reasonable structure and low cost.

[0005] An object of the present application is achieved as follows: A kind of three-wire DC motor steering and rotational speed signal transmission circuit, including motor power positive terminal, motor speed negative terminal and ground transmission terminal, further including multiple magnetic ring arranged on the rotating shaft of DC motor and the Hall sensor driven by multiple magnetic ring, Hall sensor is equipped with Hall positive voltage terminal, direction signal output pin, speed signal output pin and Hall ground terminal, the motor power positive terminal and the motor speed negative terminal are electrically connected by rectifier filter circuit, voltage stabilizing circuit with Hall positive voltage terminal, the ground transmission terminal is electrically connected with Hall ground terminal;Direction signal output pin and speed signal output pin are indirectly or directly electrically connected with Hall ground terminal by signal superposition circuit, to realize that the direction signal and speed signal generated by Hall sensor are superimposed together with the static current of voltage stabilizing circuit, Hall sensor and are transmitted to output by ground transmission terminal.This technology makes full use of original 3-core cable (3-core cable is connected with above-mentioned motor power positive terminal, motor speed negative terminal and ground transmission terminal), after circuit processing, it simultaneously achieves the functions of direct control, reverse control, PWM speed regulation, transmission motor real-time speed and direction signal for DC motor.Reduces cable and supporting wiring terminal material cost, and installation cost of door opener.

[0006] The object of the application can also be solved by the following technical measures: As a more specific scheme, the voltage stabilizing circuit and the signal superposition circuit include a voltage stabilizer, a first pull-up resistor and a second pull-up resistor, the voltage stabilizer is provided with a positive terminal, a voltage stabilizing output terminal and a negative terminal, and the positive terminal of the voltage stabilizer is electrically connected with the motor power positive terminal and the motor speed negative terminal through the rectifier filter circuit.

[0007] The negative terminal of the voltage stabilizer is electrically connected with the ground transmission terminal, the Hall sensor is an internal open-drain output direction Hall sensor, the voltage stabilizing output terminal of the voltage stabilizer is electrically connected with the speed signal output pin and the direction signal output pin of the Hall sensor through the first pull-up resistor and the second pull-up resistor, respectively, to realize that the two currents generated by the speed signal output pin and the direction signal output pin indirectly flow out to the ground transmission terminal through the Hall ground terminal.

[0008] The voltage stabilizing output terminal of the voltage stabilizer is also electrically connected with the Hall positive voltage terminal of the Hall sensor through a power isolation circuit.

[0009] The voltage stabilizer is a high-voltage stabilizer, the voltage stabilizing output terminal provides a 5V output, and the resistance values of the first pull-up resistor and the second pull-up resistor are both 1K, so that the current flowing out of the Hall ground terminal is increased by 0mA or 5mA.

[0010] As a further another scheme, the voltage stabilizing circuit and the signal superimposition circuit comprise a voltage stabilizer, a first transistor and a second transistor, the voltage stabilizer is provided with a positive electrode pin, a voltage stabilizing output pin and a negative electrode pin, and the positive electrode pin of the voltage stabilizer is electrically connected with the motor power positive electrode end and the motor speed regulating negative electrode end through the rectification filtering circuit.

[0011] The negative electrode pin of the voltage stabilizer is electrically connected with the ground transmission end; the Hall sensor is a directional Hall sensor, the voltage stabilizing output pin of the voltage stabilizer is electrically connected with the collector of the first transistor and the collector of the second transistor, the directional signal output pin and the speed signal output pin of the Hall sensor are electrically connected with the base of the first transistor and the base of the second transistor respectively, and the emitter of the first transistor and the emitter of the second transistor are electrically connected with the ground transmission end, so that the two-way currents generated by the directional signal output pin and the speed signal output pin are directly inverted and output to the ground transmission end through the first transistor and the second transistor respectively.

[0012] The voltage stabilizing output pin of the voltage stabilizer is also electrically connected with the Hall positive voltage end of the Hall sensor through a power supply isolation circuit.

[0013] The voltage stabilizer is a high-voltage stabilizer, and the voltage stabilizing output pin provides a 5V output; the voltage stabilizing output pin is electrically connected with the collector of the first transistor and the collector of the second transistor through a first resistor and a second resistor respectively, and the resistance values of the first resistor and the second resistor are both 1K; the directional signal output pin and the speed signal output pin are electrically connected with the power supply isolation circuit through a third resistor and a fourth resistor respectively.

[0014] The above power supply isolation circuit can reduce the influence of the Hall signal output on the Hall power supply ripple.

[0015] As a further scheme, the voltage stabilizing circuit further comprises a voltage stabilizer protection circuit, the voltage stabilizer protection circuit comprises a unidirectional transient diode (unidirectional TVS tube), and the unidirectional transient diode is connected between the positive electrode pin and the negative electrode pin. The unidirectional TVS tube is used for protecting the voltage stabilizer from being damaged by a sharp peak voltage.

[0016] As a further scheme, the Hall sensor is arranged on a carbon brush plate, two carbon brush electrodes are arranged on the carbon brush plate, and the two carbon brush electrodes are electrically connected with the motor power positive electrode end and the motor speed regulating negative electrode end respectively; a motor electromagnetic compatibility suppression device is further arranged on the carbon brush plate, which is helpful to absorb high-frequency noise of a specific frequency band and is conducive to passing the EMC certification.

[0017] As a further scheme, a bidirectional transient diode (bidirectional TVS tube) is further arranged between the two carbon brush electrodes. The bidirectional TVS tube is used for suppressing a sharp peak voltage generated when the motor operates, so as to protect other circuits.

[0018] Another object of the present application is to provide a three-wire DC motor steering and speed signal transmission method with simple control circuit.

[0019] Another object of the present application is achieved as follows: A three-wire DC motor steering and speed signal transmission method, by setting a Hall sensor for detecting a multi-pole magnetic ring on the DC motor rotating shaft, using the power supply of the DC motor to supply power to the Hall sensor after voltage stabilization by a voltage stabilizing circuit, and superimposing the speed signal and steering signal of the Hall sensor for transmission through the ground wire; at the same time, the ground wire is compatible with the transmission of the anti-interference grounding of the DC motor, the static current of the voltage stabilizing circuit and the static current of the Hall sensor.

[0020] Another object of the present application can also be solved by the following technical measures: As a more specific scheme, the speed and steering of the DC motor are analyzed from the ground wire current signal by a dual-channel current comparator or an AD sampling circuit.

[0021] The beneficial effects of the present application are as follows: (1) In the present application, the Hall sensor is powered by the driving power supply of the DC motor, wherein the positive voltage of the Hall sensor is separately provided by the positive terminal of the motor power supply during the forward or reverse rotation of the motor, or is commonly provided by the positive terminal of the motor power supply and the negative terminal of the motor speed regulation when the motor is stopped, and the negative voltage of the Hall sensor is provided by the ground transmission terminal.

[0022] (2) In the present application, the direction signal and speed signal of the Hall sensor are superimposed and transmitted from the ground wire of the Hall sensor.

[0023] (3) The present application can be based on the original three-wire connection of the DC motor (without damaging the original wiring), wherein two wires are used for power supply of the motor and the Hall sensor, and the other wire is used for anti-interference grounding and can also be used for transmission of the direction signal of the Hall sensor, the speed signal of the Hall sensor, the static current of the Hall sensor and the static current of the voltage stabilizing circuit. Therefore, under the condition of the same performance, the installation and material costs are lower than those of similar circuits; under the condition of similar costs, the performance is better, the control is more accurate, and it is more suitable for the application of the actual early buried motor line of the courtyard door, thereby improving the competitiveness of the product. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The circuit diagram of an embodiment of the present application.

[0025] Figure 2 The circuit diagram of an embodiment of the present application. Figure 1 The current waveform diagram of the ground transmission terminal in the circuit.

[0026] Figure 3Circuit diagram for another embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application is further described below in conjunction with the accompanying drawings and embodiments: Embodiment one, referring to Figure 1 As shown in the figure, a three-wire DC motor steering and rotation speed signal transmission circuit includes a motor power positive terminal J2, a motor speed regulation negative terminal J5, and a ground transmission terminal J8. It also includes a multi-pole magnetic ring arranged on the rotating shaft of the DC motor and a Hall sensor U1 driven by the multi-pole magnetic ring. The Hall sensor U1 is provided with a Hall positive voltage terminal VCC, a direction signal output pin (direction), a speed signal output pin (speed), and a Hall ground terminal GND. The motor power positive terminal J2 and the motor speed regulation negative terminal J5 are electrically connected to the Hall positive voltage terminal VCC through a rectification filtering circuit and a voltage stabilizing circuit. The ground transmission terminal J8 is electrically connected to the Hall ground terminal GND. The direction signal output pin (direction) and the speed signal output pin (speed) are indirectly electrically connected to the Hall ground terminal GND through a signal superposition circuit to realize the superposition of the direction signal and the speed signal generated by the Hall sensor U1 and the transmission of the signals through the ground transmission terminal J8.

[0028] The voltage stabilizing circuit and the signal superposition circuit include a voltage stabilizer IC1, a first pull-up resistor R5, and a second pull-up resistor R6. The voltage stabilizer IC1 is provided with a positive terminal VIN, a voltage stabilizing output pin OUT, and a negative terminal GND. The positive terminal VIN of the voltage stabilizer IC1 is electrically connected to the motor power positive terminal J2 and the motor speed regulation negative terminal J5 through the rectification filtering circuit.

[0029] The rectification filtering circuit includes a diode D4, a diode D2, an inductor L3, and a capacitor C10. The specific connection mode is shown in the figure. Figure 1

[0030] The negative terminal GND of the voltage stabilizer IC1 is electrically connected to the ground transmission terminal J8. The Hall sensor U1 is an internal open-drain output direction Hall sensor U1. The voltage stabilizing output pin OUT of the voltage stabilizer IC1 is electrically connected to the speed signal output pin and the direction signal output pin of the Hall sensor U1 through the first pull-up resistor R5 and the second pull-up resistor R6, respectively, to realize the indirect flow of the two currents generated by the speed signal output pin and the direction signal output pin to the ground transmission terminal J8 through the Hall ground terminal GND.

[0031] The voltage stabilizing output pin OUT of the voltage stabilizer IC1 is also electrically connected to the Hall positive voltage terminal VCC of the Hall sensor U1 through a power isolation circuit.

[0032] ​The voltage stabilizer IC1 is a high-voltage stabilizer IC1, the voltage stabilizer output pin OUT provides a 5V output, and the resistance values of the first pull-up resistor R5 and the second pull-up resistor R6 are both 1K, so that the current flowing out of the Hall grounding end GND is amplified by 0mA or 5mA.

[0033] The power supply isolation circuit includes a diode D5 and a capacitor C2, one end of the diode D5 is electrically connected with the voltage stabilizer output pin OUT, one end of the capacitor C2 is electrically connected with the ground transmission end J8, and the other end of the diode D5, the other end of the capacitor C2 and the Hall positive voltage end VCC are electrically connected with each other.

[0034] The voltage stabilizer circuit further includes a voltage stabilizer protection circuit, which includes a unidirectional transient diode D3 connected between the positive pin VIN and the negative pin GND.

[0035] The Hall sensor U1 is arranged on a carbon brush plate, the carbon brush plate is provided with two carbon brush electrodes J3 and J4, the two carbon brush electrodes J3 and J4 are respectively electrically connected with the motor power supply positive end J2 and the motor speed regulation negative end J5, and the carbon brush plate is further provided with a motor electromagnetic compatibility (EMC) suppression device. Figure 1 The motor electromagnetic compatibility suppression device includes capacitors C3, C4, C5, C6, C7, C8, C9, inductors L1 and L2, and the connection of the motor electromagnetic compatibility suppression device is shown in

[0036] The two carbon brush electrodes J3 and J4 are further provided with a bidirectional transient diode D6.

[0037] The carbon brush plate is further provided with a grounding point J1 connected with the shell of the DC motor, and the grounding point J1 is not welded with a wire.

[0038] The above-mentioned Hall sensor U1 with direction is a double-channel Hall sensor, the model number of which is YS2526; the high-voltage stabilizer (high-voltage LDO) IC1 has a model number of SL6203H and a high-voltage resistance of 80V; the unidirectional transient diode D3 has a model number of SMAJ43A; the bidirectional transient diode D6 has a model number of SMCJ48CA-T3; the diodes D2, D4 and D5 are all silicon rectifier diodes (ordinary diodes M7); the parameters of the capacitor C2 are 105 / 50V, the parameters of the capacitor C3 are 333 / 280V, the parameters of the capacitor C4 are 2200P / 1000V, the parameters of the capacitor C5 are 82P / 500V, the parameters of the capacitor C6 are 100P / 1000V, the parameters of the capacitor C7 are 82P / 500V, the parameters of the capacitor C8 are 2200P / 1000V, the parameters of the capacitor C9 are 82P / 500V, the parameters of the capacitor C10 are 105 / 50V, and the parameter of the inductor L3 is 1mH.

[0039] The working principle is that the multi-pole magnetic ring placed on the rotor shaft of the motor is placed in front of the Hall sensor U1. When the motor is running, the Hall sensor U1 will sense the rotation of the magnetic ring, and according to the different directions, the direction signal output pin (direction) of the Hall sensor U1 will output a direct current high level 5V or low level 0V. Since the chip internally uses open drain output, the pull-up resistor is 1K, then the current flowing out of the Hall sensor U1 GND will increase by 0mA or 5mA depending on the direction.

[0040] The speed signal output pin (speed) of the Hall sensor U1 outputs a square wave signal during the rotation of the magnet. Since the pull-up resistor is 1K, the current flowing out of the Hall GND will increase by 0mA or 5mA. The superposition of the two currents and the static current of IC1, U1 outputs a current waveform at J8 port as shown in Figure 2 .

[0041] Thus, the function of transmitting the direction and speed signals of the Hall and the negative pole of the Hall power supply from a line to the control board is completed.

[0042] The control board (not shown in the figure) compares the two currents through the dual-channel current comparator, sets the threshold current A for A channel and the threshold current B for B channel. When the motor is running forward, the A channel comparator outputs a 0~5V square wave, and the B channel comparator outputs a low level. After the MCU on the control board recognizes the above signals, it judges that the motor is running forward, and counts the number of square waves output by the A channel comparator to determine the motor position and speed.

[0043] When the motor is running in reverse, the B channel comparator outputs a 0~5V square wave, and the A channel comparator outputs a high level 1. After the MCU recognizes the above signals, it judges that the motor is running in reverse, and counts the number of square waves output by the B channel comparator to determine the motor position and speed.

[0044] If the MCU resources on the controller are sufficient, AD sampling analysis can also be used to separate the signals.

[0045] Example two, the difference from example one is: as shown in Figure 3 , the two signals of the Hall sensor are inverted and then output through Q1 and Q2, and the other principles are the same. Specifically: the voltage stabilizing circuit and the signal superposition circuit comprise a voltage stabilizer IC1, a first transistor Q1 and a second transistor Q2, the voltage stabilizer IC1 is provided with a positive electrode pin VIN, a voltage stabilizing output pin OUT and a negative electrode pin GND, and the positive electrode pin VIN of the voltage stabilizer IC1 is electrically connected with the positive electrode end J2 of the motor power supply and the motor speed regulating negative electrode end J5 through the rectifier filter circuit.

[0046] The negative pin GND of the voltage stabilizer IC1 is electrically connected with the ground transmission terminal J8; the Hall sensor U1 is a direction Hall sensor U1, the voltage stabilizing output pin OUT of the voltage stabilizer IC1 is electrically connected with the collector of the first triode Q1 and the collector of the second triode Q2, the direction signal output pin and the speed signal output pin of the Hall sensor U1 are electrically connected with the base of the first triode Q1 and the base of the second triode Q2 respectively, the emitter of the first triode Q1 and the emitter of the second triode Q2 are electrically connected with the ground transmission terminal J8, so that the two-way current generated by the direction signal output pin and the speed signal output pin is directly inverted and output to the ground transmission terminal J8 through the first triode Q1 and the second triode Q2 respectively.

[0047] The voltage stabilizing output pin OUT of the voltage stabilizer IC1 is also electrically connected with the Hall positive voltage terminal VCC of the Hall sensor U1 through a power supply isolation circuit.

[0048] The voltage stabilizer IC1 is a high-voltage voltage stabilizer IC1, and the voltage stabilizing output pin OUT provides a 5V output; the voltage stabilizing output pin OUT is electrically connected with the collector of the first triode Q1 and the collector of the second triode Q2 through a first resistor R4 and a second resistor R3 respectively, and the resistance values of the first resistor R4 and the second resistor R3 are both 1K; the direction signal output pin and the speed signal output pin are electrically connected with the power supply isolation circuit through a third resistor R6 and a fourth resistor R5 respectively, as shown in the figure.

[0049] The ground transmission terminal J8 is also provided with a diode D1 between the ground transmission terminal J8 and the rectifier filter circuit, and the diode D1 is a silicon rectifier diode (ordinary diode M7).

[0050] The models of the first triode Q1 and the second triode Q2 are both 4401.

[0051] A transmission method of the steering and speed signals of a three-wire direct current motor, a Hall sensor U1 is arranged to detect a multi-pole magnetic ring on the rotating shaft of the direct current motor, the power supply of the direct current motor is used to supply power to the Hall sensor U1 after being stabilized by a voltage stabilizing circuit, and the speed signal and the steering signal of the Hall sensor U1 are superimposed and transmitted through the ground wire; at the same time, the ground wire is compatible with the anti-interference grounding of the direct current motor, the transmission of the static current of the voltage stabilizing circuit and the static current of the Hall sensor U1.

[0052] The speed and steering of the direct current motor are analyzed from the ground wire current signal through a two-way current comparator or an AD sampling circuit.

[0053] The above are the preferred schemes of the present application, which show and describe the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A three-wire DC motor commutation and speed signal transmission circuit comprising a motor power positive terminal, a motor speed control negative terminal and a ground transmission terminal, characterized by: The application also comprises a multi-pole magnetic ring arranged on the rotating shaft of the direct current motor and a Hall sensor driven by the multi-pole magnetic ring, wherein the Hall sensor is provided with a Hall positive voltage end, a direction signal output pin, a speed signal output pin and a Hall ground end, the motor power positive end and the motor speed negative end are electrically connected with the Hall positive voltage end through a rectification filtering circuit and a voltage stabilizing circuit, and the ground transmission end is electrically connected with the Hall ground end. The direction signal output pin and the speed signal output pin are indirectly or directly electrically connected with the Hall ground end through a signal superposition circuit, so that the direction signal and the speed signal generated by the Hall sensor are superposed with the static current of the voltage stabilizing circuit and the Hall sensor and are transmitted and output through the ground transmission end. The voltage stabilizing circuit and the signal superposition circuit comprise a voltage stabilizer, a first pull-up resistor and a second pull-up resistor, the voltage stabilizer is provided with a positive pin, a voltage stabilizing output pin and a negative pin, the positive pin of the voltage stabilizer is electrically connected with the motor power positive end and the motor speed negative end through the rectification filtering circuit. The negative pin of the voltage stabilizer is electrically connected with the ground transmission end, the voltage stabilizer is an internal open-drain output direction Hall sensor, the voltage stabilizing output pin of the voltage stabilizer is electrically connected with the speed signal output pin and the direction signal output pin of the Hall sensor through the first pull-up resistor and the second pull-up resistor, respectively, so that the two current paths generated by the speed signal output pin and the direction signal output pin flow out to the ground transmission end through the Hall ground end. The voltage stabilizing output pin of the voltage stabilizer is also electrically connected with the Hall positive voltage end of the Hall sensor through a power isolation circuit. The power isolation circuit comprises a diode and a capacitor, one end of the diode is electrically connected with the voltage stabilizing output pin, one end of the capacitor is electrically connected with the ground transmission end, and the other end of the diode, the other end of the capacitor and the Hall positive voltage end are electrically connected with each other.

2. The circuit of claim 1, wherein: The voltage stabilizer is a high-voltage stabilizer, the voltage stabilizing output pin provides a 5V output, and the resistance values of the first pull-up resistor and the second pull-up resistor are both 1K, so that the current flowing out of the Hall ground end is increased by 0mA or 5mA.

3. The circuit of claim 1 or 2, wherein: The voltage stabilizing circuit further comprises a voltage stabilizer protection circuit, and the voltage stabilizer protection circuit comprises a unidirectional transient diode connected between the positive pin and the negative pin.

4. The circuit of claim 1, wherein: The Hall sensor is arranged on a carbon brush plate, the carbon brush plate is provided with two carbon brush electrodes, the two carbon brush electrodes are electrically connected with the motor power positive end and the motor speed negative end, respectively, and the carbon brush plate is further provided with a motor electromagnetic compatibility suppression device.

5. The circuit of claim 4, wherein: The two carbon brush electrodes are further provided with a bidirectional transient diode.

6. A three-wire DC motor commutation and speed signal transmission circuit comprising a motor supply positive terminal, a motor speed control negative terminal and a ground transmission terminal, characterized by: The application also comprises a multi-pole magnetic ring arranged on the rotating shaft of the direct current motor and a Hall sensor driven by the multi-pole magnetic ring, wherein the Hall sensor is provided with a Hall positive voltage end, a direction signal output pin, a speed signal output pin and a Hall ground end, the motor power positive end and the motor speed negative end are electrically connected with the Hall positive voltage end through a rectification filtering circuit and a voltage stabilizing circuit, and the ground transmission end is electrically connected with the Hall ground end. The direction signal output pin and the speed signal output pin are indirectly or directly electrically connected with the Hall grounding end through a signal superposition circuit, so that the direction signal and the speed signal generated by the Hall sensor are superposed with the static current of the Hall sensor and the voltage stabilizing circuit and are transmitted to the grounding transmission end. The voltage stabilizing circuit and the signal superposition circuit comprise a voltage stabilizer, a first transistor and a second transistor, the voltage stabilizer is provided with a positive pin, a voltage stabilizing output pin and a negative pin, the positive pin of the voltage stabilizer is electrically connected with the motor power positive end and the motor speed regulating negative end through the rectifier filter circuit. The negative pin of the voltage stabilizer is electrically connected with the grounding transmission end. The voltage stabilizing output pin of the voltage stabilizer is electrically connected with the collector of the first transistor and the collector of the second transistor, the direction signal output pin and the speed signal output pin of the Hall sensor are electrically connected with the base of the first transistor and the base of the second transistor respectively, the emitter of the first transistor and the emitter of the second transistor are electrically connected with the grounding transmission end, so that two currents generated by the direction signal output pin and the speed signal output pin are directly inverted through the first transistor and the second transistor and then output to the grounding transmission end. The voltage stabilizing output pin of the voltage stabilizer is also electrically connected with the Hall positive voltage end of the Hall sensor through a power supply isolation circuit.

7. The transmission circuit for the direction and speed signals of a three-wire DC motor according to claim 6, characterized in that: The power supply isolation circuit comprises a diode and a capacitor, one end of the diode is electrically connected with the voltage stabilizing output pin, one end of the capacitor is electrically connected with the grounding transmission end, the other end of the diode, the other end of the capacitor and the Hall positive voltage end are electrically connected with each other.

8. The circuit of claim 6 or 7, wherein: The voltage stabilizer is a high-voltage voltage stabilizer, the voltage stabilizing output pin provides a 5V output, the voltage stabilizing output pin is electrically connected with the collector of the first transistor and the collector of the second transistor through a first resistor and a second resistor respectively, the resistance values of the first resistor and the second resistor are both 1K, the direction signal output pin and the speed signal output pin are electrically connected with the power supply isolation circuit through a third resistor and a fourth resistor respectively.

9. The circuit of claim 1, wherein: The voltage stabilizing circuit further comprises a voltage stabilizer protection circuit, the voltage stabilizer protection circuit comprises a unidirectional transient diode, the unidirectional transient diode is connected between the positive pin and the negative pin.

10. The circuit of claim 9, wherein: The Hall sensor is arranged on a carbon brush plate, the carbon brush plate is provided with two carbon brush electrodes, the two carbon brush electrodes are electrically connected with the motor power positive end and the motor speed regulating negative end respectively, and the carbon brush plate is further provided with a motor electromagnetic compatibility suppression device. A bidirectional transient diode is further arranged between the two carbon brush electrodes.

Images