Direct current motor low temperature starting circuit and control method thereof

Abstract

The application discloses a low-temperature starting circuit of a direct-current motor and a control method thereof, wherein the low-temperature starting circuit of the direct-current motor comprises a temperature detection module for detecting the current environmental temperature of the motor, an energy storage voltage detection module for detecting the energy storage voltage of the motor, an energy storage voltage boosting module for boosting the motor driving voltage, an energy storage power discharge control module for discharging the boosted motor driving voltage, and a motor forward and reverse rotation module for driving the motor to rotate forward and reversely. The low-temperature starting circuit of the direct-current motor detects the current environmental temperature of the motor through the temperature detection module and drives the motor to rotate forward and reversely through the motor forward and reverse rotation module, so that the motor starting voltage is in a corresponding relationship with the temperature, the boosting voltage and the starting voltage are adjusted according to the environmental temperature, the forward and reverse shaking control is added before the motor starts to enter the normal rotating direction, the resistance of the initial lubricating oil adhesion is reduced, the reliability of the motor starting at low temperature is improved, and the cost is relatively low.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor starting control, and particularly relates to a low-temperature starting circuit of a direct-current motor and a control method thereof. BACKGROUND

[0002] At present, direct-current motors are used for transmission control in many household appliances and industrial fields. However, the lubricating oil flowability decreases at low temperatures, and the motor often encounters starting difficulties or even failure, which affects the use adaptability of the electrical appliance or equipment.

[0003] In order to solve this problem, the power of the switching power supply and the direct-current motor often needs to be increased to improve the output torque and overcome the large resistance during starting, but the cost is high. SUMMARY

[0004] In order to solve the above problems, the present application provides a low-temperature starting circuit of a direct-current motor, which reduces the initial lubricating oil adhesion resistance, improves the reliability of the motor starting at low temperatures, and has low cost.

[0005] Another object of the present application is to provide a control method.

[0006] The technical scheme adopted by the present application is as follows:

[0007] A low-temperature starting circuit of a direct-current motor includes a temperature detection module for detecting the current environmental temperature of the motor, an energy storage voltage detection module for detecting the energy storage voltage of the motor, a boost energy storage module for boosting the motor drive voltage, an energy storage power discharge control module for discharging control of the boosted motor drive voltage, and a motor forward and reverse rotation module for driving the motor forward and reverse rotation. The temperature detection module is electrically connected to the energy storage voltage detection module, the boost energy storage module, the energy storage power discharge control module and the motor forward and reverse rotation module. The energy storage power discharge control module is electrically connected to the boost energy storage module and the motor forward and reverse rotation module.

[0008] Preferably, the temperature detection module includes a first chip U1, a first resistor R1, a second resistor R2 and a first capacitor C1. The first pin of the first chip U1 is connected in parallel to one end of the first resistor R1, one end of the second resistor R2 and one end of the first capacitor C1. The other end of the first resistor R1 is connected to a first voltage, and the other end of the second resistor R2 and the other end of the first capacitor C1 are both grounded.

[0009] Preferably, the energy storage voltage detection module comprises a third resistor R3, a fourth resistor R4 and a second capacitor C2, one end of the third resistor R3 is electrically connected with the second voltage VCC2, the other end of the third resistor R3 is electrically connected with one end of the second capacitor C2, one end of the fourth resistor R4 and the fourteenth pin of the first chip U1, the other end of the second capacitor C2 and the other end of the fourth resistor R4 are both grounded.

[0010] Preferably, the boost energy storage module comprises a second chip U2, a first inductor L1, a third capacitor C3 and a fourth capacitor C4, the second pin of the second chip U2 is connected with one end of the first inductor L1 and one end of the third capacitor C3 in parallel, the other end of the third capacitor C3 is connected with the sixth pin of the second chip U2, the other end of the first inductor L1 is connected with one end of the fourth capacitor C4, one end of the seventh resistor R7, one end of the first electrolytic capacitor EC1 and one end of the ninth resistor R9 in parallel, the other end of the fourth capacitor C4 is connected with the fourth pin of the second chip U2, one end of the sixth resistor R6, one end of the eighth resistor R8 and the other end of the seventh resistor R7 in parallel, the other end of the sixth resistor R6 is connected with the twentieth pin of the first chip U1, the other end of the ninth resistor is connected with the second voltage VCC2 and one end of the second electrolytic capacitor EC2 in parallel, the third pin of the second chip U2 is electrically connected with the third voltage VCC and one end of the fifth resistor R5, the other end of the fifth resistor R5 is electrically connected with the fifth pin of the second chip U2, the first pin of the second chip U2, the other end of the eighth resistor R8, the other end of the first electrolytic capacitor EC1 and the other end of the second electrolytic capacitor EC2 are all grounded.

[0011] Preferably, the energy storage power discharge control module comprises a first transistor Q1, a second transistor Q2, a tenth resistor R10, an eleventh resistor R11 and a twelfth resistor R12, the base of the first transistor Q1 is connected with the nineteenth pin of the first chip U1 after being connected with the tenth resistor R10 in series, the collector of the first transistor Q1 is connected with one end of the twelfth resistor R12 and the base of the second transistor Q2 in parallel after being connected with the eleventh resistor R11 in series, the other end of the twelfth resistor R12 and the emitter of the second transistor Q2 are connected with the second voltage VCC2, the emitter of the first transistor Q1 is grounded.

[0012] Preferably, the motor forward / reverse module includes a third chip U3, a DC motor M1, a first diode D1, and a second diode D2. The first pin of the third chip U3 is connected to the eleventh pin of the first chip U1, the second pin of the third chip U3 is connected to the twelfth pin of the first chip U1, the third pin of the third chip U3 is grounded, the fourth pin of the third chip U3 is connected in parallel to the cathode of the first diode D1 and the cathode of the second diode D2, the anode of the first diode D1 is connected to the third voltage VCC, the anode of the second diode D2 is connected to the collector of the second transistor Q2, the fifth and sixth pins of the third chip U3 are both electrically connected to the first pin of the DC motor M1, and the seventh and eighth pins of the third chip U3 are both electrically connected to the second pin of the DC motor M1.

[0013] Preferably, the first resistor R1 is an adjustable resistor.

[0014] Another technical solution of the present invention is implemented as follows:

[0015] A control method for using the aforementioned DC motor low-temperature starting circuit specifically includes the following steps:

[0016] S1. The current ambient temperature of the motor is detected in real time by the temperature detection module, and it is determined whether the current ambient temperature is higher than the first preset temperature. If the current ambient temperature is higher than the first preset temperature, the energy storage power discharge control module is turned off, the boost energy storage module boosts the motor drive voltage, and the motor forward and reverse module supplies power to the motor with normal voltage. Otherwise, proceed to the next step.

[0017] S2. Compare the motor energy storage voltage detected by the energy storage voltage detection module with the preset voltage, and control the opening and closing of the energy storage power discharge control module according to the comparison result, so as to start or stop the forward and reverse rotation of the motor forward and reverse rotation module of the boost energy storage module, and increment the count n by one.

[0018] S3. Determine whether the count n is not less than the preset number N. If yes, turn off the energy storage power discharge control module and supply power to the motor with normal voltage. Otherwise, return to S2.

[0019] Preferably, in step S2, the opening and closing of the energy storage power discharge control module is controlled according to the comparison result, thereby causing the boost energy storage module to start or stop the forward and reverse rotation of the drive motor forward and reverse rotation module, specifically as follows:

[0020] When the motor energy storage voltage is greater than the preset voltage, the motor forward and reverse module makes the motor rotate forward, and at the same time the energy storage power discharge control module is turned on. The boost energy storage module supplies power to the motor through the energy storage power discharge control module and keeps time. If the motor energy storage voltage is not greater than the preset voltage or the preset time is reached, the energy storage power discharge control module is turned off, and the boost energy storage module boosts the motor drive voltage.

[0021] When the motor energy storage voltage exceeds the preset voltage again, the motor reverses through the motor forward / reverse module, and the energy storage power discharge control module is turned on. The boost energy storage module supplies power to the motor through the energy storage power discharge control module and keeps time. If the motor energy storage voltage does not exceed the preset voltage or the preset time is reached, the energy storage power discharge control module is turned off, and the boost energy storage module boosts the motor drive voltage.

[0022] Preferably, S2 further includes:

[0023] If the current ambient temperature is not higher than the second preset temperature, the energy storage voltage of the boost energy storage module will be increased through the temperature detection module, and the second preset temperature will be lower than the first preset temperature.

[0024] Compared with existing technologies, the DC motor low-temperature starting circuit of the present invention detects the current ambient temperature of the motor through a temperature detection module, detects the motor's energy storage voltage through an energy storage voltage detection module, boosts the motor drive voltage through a boost energy storage module, controls the discharge of the boosted motor drive voltage through an energy storage power discharge control module, and drives the motor to rotate in both directions through a motor forward and reverse rotation module. This makes the motor starting voltage correspond to the temperature, adjusts the boost voltage and starting voltage according to the ambient temperature, and adds forward and reverse jitter control before the motor starts and enters the normal rotation direction, reducing the resistance of initial lubricating oil adhesion, improving the reliability of motor starting at low temperatures, and reducing costs. Attached Figure Description

[0025] Figure 1 This is a circuit diagram of a low-temperature starting circuit for a DC motor provided in Embodiment 1 of the present invention;

[0026] Figure 2 This is a flowchart of a control method for a low-temperature starting circuit of a DC motor provided in Embodiment 2 of the present invention.

[0027] Explanation of reference numerals in the attached figures

[0028] 1-Temperature detection module, 2-Energy storage voltage detection module, 3-Boost energy storage module, 4-Energy storage power discharge control module, 5-Motor forward and reverse rotation module. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] Example 1

[0031] This invention provides a low-temperature starting circuit for a DC motor, such as... Figure 1 As shown, the system includes a temperature detection module 1 for detecting the current ambient temperature of the motor, an energy storage voltage detection module 2 for detecting the energy storage voltage of the motor, a boost energy storage module 3 for boosting the motor drive voltage, an energy storage power discharge control module 4 for discharging the boosted motor drive voltage, and a motor forward and reverse rotation module 5 for driving the motor to rotate in both directions. The temperature detection module 1 is electrically connected to the energy storage voltage detection module 2, the boost energy storage module 3, the energy storage power discharge control module 4, and the motor forward and reverse rotation module 5. The energy storage power discharge control module 4 is electrically connected to the boost energy storage module 3 and the motor forward and reverse rotation module 5.

[0032] In this way, the current ambient temperature of the motor is detected by the temperature detection module 1, the energy storage voltage of the motor is detected by the energy storage voltage detection module 2, the motor drive voltage is boosted by the boost energy storage module 3, the boosted motor drive voltage is discharged by the energy storage power discharge control module 4, and the motor is driven to rotate in both directions by the motor forward and reverse module 5. Thus, the motor starting voltage corresponds to the temperature. The boost voltage and starting voltage are adjusted according to the ambient temperature. Before the motor starts and enters the normal rotation direction, forward and reverse jitter control is added to reduce the resistance of initial lubricating oil adhesion, improve the reliability of motor starting at low temperature and reduce cost.

[0033] The temperature detection module 1 includes a first chip U1, a first resistor R1, a second resistor R2, and a first capacitor C1. A first pin of the first chip U1 is connected in parallel to one end of the first resistor R1, one end of the second resistor R2, and one end of the first capacitor C1. The other end of the first resistor R1 is connected to a first voltage, and the other ends of the second resistor R2 and the first capacitor C1 are both grounded. The first resistor R1 is an adjustable resistor.

[0034] In this way, the current ambient temperature is measured by dividing the first voltage (i.e., 5V voltage) by the first resistor R1 and the second resistor R2 of the temperature detection module 1.

[0035] The energy storage voltage detection module 2 includes a third resistor R3, a fourth resistor R4, and a second capacitor C2. One end of the third resistor R3 is electrically connected to the second voltage VCC2, and the other end of the third resistor R3 is electrically connected to one end of the second capacitor C2, one end of the fourth resistor R4, and the fourteenth pin of the first chip U1. The other ends of the second capacitor C2 and the fourth resistor R4 are both grounded.

[0036] In this way, the energy storage voltage at the second voltage VCC2 is detected in real time by the energy storage voltage detection module 2.

[0037] The boost energy storage module 3 includes a second chip U2, a first inductor L1, a third capacitor C3, and a fourth capacitor C4. The second pin of the second chip U2 is connected in parallel to one end of the first inductor L1 and one end of the third capacitor C3. The other end of the third capacitor C3 is connected to the sixth pin of the second chip U2. The other end of the first inductor L1 is connected in parallel to one end of the fourth capacitor C4, one end of the seventh resistor R7, one end of the first electrolytic capacitor EC1, and one end of the ninth resistor R9. The other end of the fourth capacitor C4 is connected in parallel to the fourth pin of the second chip U2, one end of the sixth resistor R6, and the eighth resistor R9. One end of resistor R8 and the other end of the seventh resistor R7, the other end of the sixth resistor R6 are connected to the twentieth pin of the first chip U1, the other end of the ninth resistor is connected in parallel with the second voltage VCC2 and one end of the second electrolytic capacitor EC2, the third pin of the second chip U2 is electrically connected to the third voltage VCC and one end of the fifth resistor R5, the other end of the fifth resistor R5 is electrically connected to the fifth pin of the second chip U2, and the first pin of the second chip U2, the other end of the eighth resistor R8, the other end of the first electrolytic capacitor EC1 and the other end of the second electrolytic capacitor EC2 are all grounded.

[0038] In this way, the boost energy storage module 3 uses the second chip U2 to boost the rated drive voltage VCC of the motor according to the ambient temperature. The sixth resistor R6 and the eighth resistor R8, which are controlled by the first chip U1, are connected in parallel to obtain different boost voltages VCC2. The boost voltage depends on the parallel connection of the adjustable circuit resistor (i.e., the first resistor R1).

[0039] The energy storage power discharge control module 4 includes a first transistor Q1, a second transistor Q2, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12. The base of the first transistor Q1 is connected in series with the tenth resistor R10 and then connected to the nineteenth pin of the first chip U1. The collector of the first transistor Q1 is connected in series with the eleventh resistor R11 and then connected in parallel with one end of the twelfth resistor R12 and the base of the second transistor Q2. The other end of the twelfth resistor R12 and the emitter of the second transistor Q2 are connected to the second voltage VCC2. The emitter of the first transistor Q1 is grounded.

[0040] In this way, when the boost start-up conditions are met, the energy storage power discharge control module 4 drives the DC motor through the energy stored in the energy storage capacitor. When the output level is high, it is on; otherwise, it is off.

[0041] The motor forward / reverse module 5 includes a third chip U3, a DC motor M1, a first diode D1, and a second diode D2. The first pin of the third chip U3 is connected to the eleventh pin of the first chip U1, the second pin of the third chip U3 is connected to the twelfth pin of the first chip U1, the third pin of the third chip U3 is grounded, the fourth pin of the third chip U3 is connected in parallel to the cathode of the first diode D1 and the cathode of the second diode D2, the anode of the first diode D1 is connected to the third voltage VCC, the anode of the second diode D2 is connected to the collector of the second transistor Q2, the fifth and sixth pins of the third chip U3 are both electrically connected to the first pin of the DC motor M1, and the seventh and eighth pins of the third chip U3 are both electrically connected to the second pin of the DC motor M1.

[0042] In this way, under the condition of low temperature start-up, the motor forward and reverse rotation module 5 drives the motor to rotate clockwise and counterclockwise through intermittent forward and reverse rotation, causing the motor to vibrate and reducing the resistance of initial lubricant adhesion.

[0043] The DC motor low-temperature starting circuit of this invention detects the current ambient temperature of the motor through a temperature detection module, detects the motor's energy storage voltage through an energy storage voltage detection module, boosts the motor drive voltage through a boost energy storage module, controls the discharge of the boosted motor drive voltage through an energy storage power discharge control module, and drives the motor to rotate in both directions through a motor forward and reverse rotation module. This makes the motor starting voltage correlated with the temperature. The boost voltage and starting voltage are adjusted according to the ambient temperature. Forward and reverse jitter control is added before the motor starts and enters the normal rotation direction to reduce the resistance of initial lubricating oil adhesion, improve the reliability of motor starting at low temperatures, and has a low cost.

[0044] Example 2

[0045] like Figure 2 As shown, Embodiment 2 of the present invention provides a control method for applying the aforementioned DC motor low-temperature starting circuit, specifically including the following steps:

[0046] S1. The current ambient temperature of the motor is detected in real time by the temperature detection module, and it is determined whether the current ambient temperature is higher than the first preset temperature. If the current ambient temperature is higher than the first preset temperature, the energy storage power discharge control module is turned off, the boost energy storage module boosts the motor drive voltage, and the motor forward and reverse module supplies power to the motor with normal voltage. Otherwise, proceed to the next step.

[0047] S2. Compare the motor energy storage voltage detected by the energy storage voltage detection module with the preset voltage, and control the opening and closing of the energy storage power discharge control module according to the comparison result, so as to start or stop the forward and reverse rotation of the motor forward and reverse rotation module of the boost energy storage module, and increment the count n by one.

[0048] S3. Determine whether the count n is not less than the preset number N. If yes, turn off the energy storage power discharge control module and supply power to the motor with normal voltage. Otherwise, return to S2.

[0049] Thus, S1 detects the ambient temperature T by measuring the voltage divider between the first resistor R1 (adjustable resistor) and the second resistor R2, and obtains the ambient temperature T through the first chip U1.

[0050] S2. When the ambient temperature T is higher than the program-set temperature T1, pin P4.1 of the first chip U1 outputs a low level, and both the first transistor Q1 and the second transistor Q2 are turned off, causing the energy storage power discharge control module to shut down and maintain the power supply to the motor at voltage VCC. Conversely, the energy storage voltage of the motor detected by the energy storage voltage detection module is compared with the preset voltage. Based on the comparison result, the opening and closing of the energy storage power discharge control module is controlled, thereby causing the boost energy storage module to start or stop driving the forward and reverse rotation of the motor forward and reverse rotation module, and the count n is incremented by one.

[0051] S3. When the count n ≥ the number of times N set by the program, the pin P4.1 of the first chip U1 outputs a low level, and both the first transistor Q1 and the second transistor Q2 are cut off, thus shutting down the energy storage power discharge control circuit, which is powered by VCC and enters normal rotation control.

[0052] In step S2, controlling the opening and closing of the energy storage power discharge control module based on the comparison result, thereby causing the boost energy storage module to start or stop the forward and reverse rotation of the drive motor forward and reverse rotation module, specifically involves:

[0053] When the motor energy storage voltage is greater than the preset voltage, the motor forward and reverse module makes the motor rotate forward, and at the same time the energy storage power discharge control module is turned on. The boost energy storage module supplies power to the motor through the energy storage power discharge control module and keeps time. If the motor energy storage voltage is not greater than the preset voltage or the preset time is reached, the energy storage power discharge control module is turned off, and the boost energy storage module boosts the motor drive voltage.

[0054] When the motor energy storage voltage exceeds the preset voltage again, the motor reverses through the motor forward / reverse module, and the energy storage power discharge control module is turned on. The boost energy storage module supplies power to the motor through the energy storage power discharge control module and keeps time. If the motor energy storage voltage does not exceed the preset voltage or the preset time is reached, the energy storage power discharge control module is turned off, and the boost energy storage module boosts the motor drive voltage.

[0055] Thus, when the ambient temperature T ≤ the program-set temperature T1, the voltage is sampled by the third resistor R3 and the fourth resistor R4. When the charging voltage Vec of the second motor capacitor EC2 ≥ VCC1, the motor is driven to rotate forward. At the same time, the pin P4.1 of the first chip U1 outputs a high level, the first transistor Q1 and the second transistor Q2 are turned on, the energy storage power discharge control module is turned on, and the motor drive is boosted with power. When the voltage of the second motor capacitor EC2 drops below or equal to VCC or reaches the program-set time t1, the pin P4.1 of the first chip U1 outputs a low level to turn off the first transistor Q1 and the second transistor Q2. The energy storage power discharge control module is turned off, and the second motor capacitor EC2 is recharged.

[0056] When the charging voltage Vec of the second motor capacitor EC2 is greater than or equal to VCC1, the motor reverses. At the same time, pin P4.1 of the first chip U1 outputs a high level, the first transistor Q1 and the second transistor Q2 are turned on, the energy storage power discharge control circuit is turned on, and the motor drive is boosted with power. When the voltage of the second motor capacitor EC2 drops below or equal to VCC or reaches the program-set timer t1, pin P4.1 of the first chip U1 outputs a low level, turning off the first transistor Q1 and the second transistor Q2. The energy storage power discharge control module is turned off, and the second motor capacitor EC2 is recharged. This process is repeated, and the count n is incremented by one.

[0057] S2 further includes:

[0058] If the current ambient temperature is not higher than the second preset temperature, the energy storage voltage of the boost energy storage module will be increased through the temperature detection module, and the second preset temperature will be lower than the first preset temperature.

[0059] Thus, when the temperature T ≤ the second preset temperature T2, the pin P4.2 of the first chip U1 outputs a low level, realizing the parallel connection of the sixth resistor R6 and the eighth resistor R8. This allows for a higher voltage to be generated at a lower temperature and stored in the second electrolytic capacitor EC2, achieving a stronger jitter drive.

[0060] The control method of this invention detects the current ambient temperature of the motor through a temperature detection module, detects the motor's energy storage voltage through an energy storage voltage detection module, boosts the motor drive voltage through a boost energy storage module, controls the discharge of the boosted motor drive voltage through an energy storage power discharge control module, and drives the motor to rotate in both directions through a motor forward and reverse rotation module. This makes the motor starting voltage correlated with the temperature. The boost voltage and starting voltage are adjusted according to the ambient temperature. Forward and reverse jitter control is added before the motor starts and enters the normal rotation direction to reduce the resistance of initial lubricating oil adhesion, improve the reliability of motor starting at low temperatures, and has a low cost.

[0061] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A low temperature starting circuit for a DC motor, characterized by The application relates to a motor driving circuit, which comprises a temperature detection module (1) for detecting the current environment temperature of a motor, an energy storage voltage detection module (2) for detecting the energy storage voltage of the motor, an energy storage voltage boosting module (3) for boosting the motor driving voltage, an energy storage power discharge control module (4) for discharging the boosted motor driving voltage, and a motor forward-reverse rotation module (5) for driving the motor to rotate forward and reversely, wherein the temperature detection module (1) is electrically connected with the energy storage voltage detection module (2), the energy storage voltage boosting module (3), the energy storage power discharge control module (4) and the motor forward-reverse rotation module (5), and the energy storage power discharge control module (4) is electrically connected with the energy storage voltage boosting module (3) and the motor forward-reverse rotation module (5). The temperature detection module (1) comprises a first chip U1, a first resistor R1, a second resistor R2 and a first capacitor C1, one end of the first resistor R1, one end of the second resistor R2 and one end of the first capacitor C1 are connected in parallel to a first pin of the first chip U1, the other end of the first resistor R1 is connected to a first voltage, and the other end of the second resistor R2 and the other end of the first capacitor C1 are both grounded. The first resistor R1 is an adjustable resistor, and the first pin (INTOP3.2) of the first chip U1 is a temperature detection pin. The energy storage voltage boosting module (3) comprises a second chip U2, a first inductor L1, a third capacitor C3 and a fourth capacitor C4, one end of the first inductor L1 and one end of the third capacitor C3 are connected in parallel to a second pin of the second chip U2, the other end of the third capacitor C3 is connected to a sixth pin of the second chip U2, the other end of the first inductor L1 is connected in parallel to one end of the fourth capacitor C4, one end of a seventh resistor R7, one end of a first electrolytic capacitor EC1 and one end of a ninth resistor R9, the other end of the fourth capacitor C4 is connected in parallel to a fourth pin of the second chip U2, one end of a sixth resistor R6, one end of an eighth resistor R8 and the other end of the seventh resistor R7, the other end of the sixth resistor R6 is connected to a twentieth pin of the first chip U1, the other end of the ninth resistor is connected in parallel to a second voltage VCC2 and one end of a second electrolytic capacitor EC2, a third pin of the second chip U2 is electrically connected to a third voltage VCC and one end of a fifth resistor R5, the other end of the fifth resistor R5 is electrically connected to a fifth pin of the second chip U2, and the first pin of the second chip U2, the other end of the eighth resistor R8, the other end of the first electrolytic capacitor EC1 and the other end of the second electrolytic capacitor EC2 are all grounded. The first pin (GND) of the second chip U2 is a grounding end, the second pin (LX) of the second chip U2 is a voltage boosting output port, the third pin (IN) of the second chip U2 is a power input port, the fourth pin (FB) of the second chip U2 is a feedback input port for receiving a voltage boosting output voltage, the fifth pin (EN) of the second chip U2 is an enabling port for receiving a control signal of the first chip U1, and the sixth pin (BS) of the second chip U2 is a voltage boosting circuit bootstrap port. The twentieth pin (P4.2 / XTAL1) of the first chip U1 is connected with the voltage-boosting energy storage module, and is used for outputting a voltage-boosting control signal.

2. The low temperature start circuit for a DC motor as set forth in claim 1, wherein The energy storage voltage detection module (2) comprises a third resistor R3, a fourth resistor R4 and a second capacitor C2, one end of the third resistor R3 is electrically connected with a second voltage VCC2, the other end of the third resistor R3 is electrically connected with one end of the second capacitor C2, one end of the fourth resistor R4 and the fourteenth pin of the first chip U1, the other end of the second capacitor C2 and the other end of the fourth resistor R4 are both grounded. The fourteenth pin (P1.7 / T2 / AN7) of the first chip U1 is a voltage detection input pin, and is connected with the energy storage voltage detection module.

3. The low temperature start circuit for a DC motor as set forth in claim 1, wherein The energy storage power discharge control module (4) comprises a first transistor Q1, a second transistor Q2, a tenth resistor R10, an eleventh resistor R11 and a twelfth resistor R12, the base of the first transistor Q1 is connected with the nineteenth pin of the first chip U1 in series with the tenth resistor R10, the collector of the first transistor Q1 is connected with the base of the second transistor Q2 in series with the eleventh resistor R11 and in parallel with one end of the twelfth resistor R12, the other end of the twelfth resistor R12 and the emitter of the second transistor Q2 are connected with the second voltage VCC2, the emitter of the first transistor Q1 is grounded. The nineteenth pin (P4.1 / XTAL2) of the first chip U1 is used as an energy storage power discharge control pin.

4. The low temperature start circuit for a DC motor of claim 3 wherein, The motor forward and reverse rotation module (5) comprises a third chip U3, a direct current motor M1, a first diode D1 and a second diode D2, the first pin of the third chip U3 is connected with the eleventh pin of the first chip U1, the second pin of the third chip U3 is connected with the twelfth pin of the first chip U1, the third pin of the third chip U3 is grounded, the fourth pin (VCC) of the third chip U3 is connected with the negative electrode of the first diode D1 and the negative electrode of the second diode D2 in parallel, the positive electrode of the first diode D1 is connected with a third voltage VCC, the positive electrode of the second diode D2 is connected with the collector of the second transistor Q2, the fifth pin and the sixth pin of the third chip U3 are both electrically connected with the first pin of the direct current motor M1, the seventh pin and the eighth pin of the third chip U3 are both electrically connected with the second pin of the direct current motor M1. The eleventh pin (PL4 / AN4 / TD) of the first chip U1 and the twelfth pin (P1.5 / AN5 / TCK) of the first chip U1 are respectively used for outputting a first motor forward and reverse rotation control signal (MOT2 DRV2) and a second motor steering control signal (MOT1 DRV2). The first pin (BI) of the third chip U3 is used for receiving the motor forward and reverse rotation control signal (MOT2 DRV2), and the first pin (BI) of the third chip U3 is used for receiving the motor forward and reverse rotation control signal (MOT1 DRV2). The fifth pin (FO) and the sixth pin (FO) of the third chip U3 are connected with the direct current motor M1, and are used for driving the motor to rotate in one direction. The seventh pin (BO) and the eighth pin (BO) of the third chip U3 are connected with the direct current motor M1, and the motor is driven to rotate in another direction.

5. A low temperature start circuit for a DC motor as claimed in any one of claims 2 to 4, characterised in that, The first resistor R1 is an adjustable resistor.

6. A control method for the low temperature starting circuit of a DC motor according to any one of claims 1 to 5, characterized in that, Specifically comprising the following steps: S1, detecting the current environment temperature of the motor through the temperature detection module, and judging whether the current environment temperature is higher than the first preset temperature, if the current environment temperature is higher than the first preset temperature, the energy storage power release control module is closed, the boost energy storage module boosts the motor driving voltage, the motor forward and reverse rotation module supplies power to the motor with normal voltage, otherwise, the next step is performed; S2, comparing the motor energy storage voltage detected by the energy storage voltage detection module with the preset voltage, controlling the opening and closing of the energy storage power release control module according to the comparison result, so as to make the boost energy storage module start or stop driving the motor forward and reverse rotation module to rotate forward and reverse, and add one to the count n; S3, judging whether the count n is not less than the preset number N, if yes, the energy storage power release control module is closed, and the motor is supplied with normal voltage, otherwise, returning to S2.

7. The control method of a direct current motor low temperature starting circuit according to claim 6, characterized by, In the step S2, the opening and closing of the energy storage power release control module is controlled according to the comparison result, so as to make the boost energy storage module start or stop driving the motor forward and reverse rotation module to rotate forward and reverse, specifically: When the motor energy storage voltage is greater than the preset voltage, the motor is made to rotate forward through the motor forward and reverse rotation module, and at the same time, the energy storage power release control module is opened, the motor is supplied with power through the boost energy storage module and the energy storage power release control module, and timing is performed; if the motor energy storage voltage is not greater than the preset voltage or the preset time is reached, the energy storage power release control module is closed, and the boost energy storage module boosts the motor driving voltage; When the motor energy storage voltage is greater than the preset voltage again, the motor is made to rotate reverse through the motor forward and reverse rotation module, and at the same time, the energy storage power release control module is opened, the motor is supplied with power through the boost energy storage module and the energy storage power release control module, and timing is performed; if the motor energy storage voltage is not greater than the preset voltage or the preset time is reached, the energy storage power release control module is closed, and the boost energy storage module boosts the motor driving voltage.

8. The control method of a direct current motor low temperature starting circuit according to any one of claims 6 or 7, characterized by, The step S2 further comprises: If the current environment temperature is not higher than the second preset temperature, the boost energy storage module energy storage voltage is increased through the temperature detection module, and the second preset temperature is lower than the first preset temperature.

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