TWI486518B - Voltage-boost control device for starter motor of motorcycle - Google Patents

Description

Booster starter motor boost control device

The present invention relates to a boost control device for a locomotive starter motor, and more particularly to a boost control device for a locomotive starter motor that utilizes a booster circuit for flexible start control.

For the engine construction of a typical locomotive, it is usually optional to start by electric or pedaling. When the user of the riding locomotive wants to start the engine by electric means, the user can press the brake with one hand and the start button with the other hand to drive the electric motor to drive the crankshaft and the spark plug to ignite the engine. The combustion chamber can begin to burn oil and gas to generate power. On the other hand, when the user wants to start the engine by pedaling, the user must step on the foot pedal on the outside of the engine to drive the starting lever to rotate via the assisting lever, and the starting rod extends into the interior of the engine transmission case. And having a starting gear that can rotate to drive the crankshaft of the engine to start the engine with the similar principle described above.

For example, please refer to FIG. 1 , which discloses a schematic diagram of a control device for a starter motor of a conventional Scooter type locomotive, wherein the control device related to the electric start in the engine 10 of the first-speed Keda locomotive mainly includes a starter motor 11 assembled in an appropriate position on the outer side of the engine 10; a start gear set 12 disposed in the engine 10 and rotatable by a drive shaft of the starter motor 11; a crankshaft 13 disposed on In the engine 10, a starting gear wheel 14 is fixed on the crankshaft 13 and can be rotated by the starting gear set 12; a control circuit 15 for controlling and starting the starting motor 11; To provide power to the control circuit 15; and a main switch 17, located between the control circuit 15 and the battery 16, to turn the control circuit 15 on or off.

Furthermore, the control circuit 15 further includes: a start button 151, a brake switch 152 and a start relay 153. When the engine 10 is electrically started, a motorcycle rider first turns on the main switch 17 with a key, then presses the brake switch 152 with one hand, and presses the start button 151 with another hand, so that the battery 16 and the start relay 153 are electrically connected. In order to drive the starter relay 153 to operate, the starter motor 11 is energized. When the rotational speed of the drive shaft of the starter motor 11 reaches a predetermined value, the crankshaft 13 of the engine 10 can be rotated via the start gear set 12 and the starter gear plate 14, thereby causing the spark plug of the engine 10 (not drawn) The fire can be normally ignited so that the combustion chamber (not shown) of the engine 10 begins to burn oil and gas to generate power.

However, the above-described control device for the starter motor of the conventional Scooter type locomotive still has the following problems in practical use. For example, the control device for the starter motor is a starter motor 11 having a voltage specification of 12 V (volts), which can be directly A power supply of 12 V voltage supplied from the battery 16 was used. However, when the start button 151 is pressed, the current in the battery 16 instantaneously flows to the starter motor 11 in a large amount, causing the voltage of the battery 16 to drop rapidly, which makes the stability of the vehicle power system and the engine ignition poor. . If the storage capacity of the battery 16 is already insufficient, it is highly likely that the engine 10 fails to ignite or the remaining power of the battery 16 is lost. Moreover, since the current of the battery 16 is instantaneously supplied to the starter motor 11 in a large amount, the starting torque of the drive shaft of the starter motor 11 is excessively excessive, and an excessive impact sound is generated to the start gear group 12. That is to start the noise. Moreover, the starting gear set 12 is also increased in gear wear due to being momentarily driven, thereby reducing its service life.

In addition, whether the control circuit 15 is activated or not depends on the locomotive knight to press the start button 151 to determine. Under normal conditions, when the engine 10 has been operating normally (referring to have reached an idle state), the locomotive knight must release the start button 151. However, whether the engine 10 has reached the normal running speed depends entirely on the personal experience of the locomotive knight to make a judgment, so that the manual pressing of the start button 151 is often performed for a long time, and the battery 16 is at a low voltage for a long time. On the contrary, the start-up motor 11 is poorly activated or damages the storage capacity and service life of the battery 16; or, the time for pressing the start button 151 multiple times is insufficient, and the engine 10 cannot be successfully started or continuously consumed. The remaining power of the battery 16 is exhausted.

Therefore, it is necessary to provide an improved control device for the locomotive starting motor to solve the problems of the prior art.

The main object of the present invention is to provide a boost control device for a locomotive starter motor, which uses a microcontroller to control a boost circuit, and the boost circuit boosts the original voltage of the battery to a starter motor of a higher voltage specification. For the flexible start control of the starter motor, since the starter motor of the higher voltage specification can provide sufficient and stable torque to the engine, the starter motor does not generate an instantaneous high current demand for the battery at the start of the start, thereby facilitating the improvement. Start the engine smoothness and the stability of the vehicle's power system and engine ignition, and relatively reduce the starting noise and the wear of the starting gear set.

A secondary object of the present invention is to provide a boost control device for a locomotive starter motor, wherein once the locomotive rider starts the control circuit through the start button and the brake switch, even if the start button and/or the brake switch are manually released, the control circuit is micro-controlled. The controller can still control the starter motor to continue the rotation of the engine crankshaft via the boost circuit, and immediately stop the boost circuit after the crankshaft rotates for a predetermined time to close the starter motor, thereby facilitating the startup efficiency and the convenience of operation, and Reduce the degree of damage to the battery.

Another object of the present invention is to provide a boost control device for a locomotive starter motor, wherein after the crankshaft rotates to a predetermined rotational speed for a predetermined period of time, or after the brake switch is pressed and the crankshaft rotates below a predetermined rotational speed for a predetermined period of time, The pressure circuit can be used to depress the alternating current of the alternator of the engine into direct current to charge the battery, and during the operation of the boosting circuit, the microcontroller controls the buck circuit to stop charging, thereby facilitating effective control of the charging voltage. And to ensure startup efficiency.

In order to achieve the above object, the present invention provides a boost control device for a locomotive starter motor, which includes a control circuit electrically connected between a battery and a starter motor for starting an engine, wherein: The control circuit includes: a microcontroller electrically connected to the battery, the microcontroller is configured to issue a boost control signal after receiving at least one start signal of the at least one start switch; or a step-down control signal is sent after a crankshaft rotates to a predetermined speed; a boosting circuit receives the boost control signal to boost the first direct current of the battery supply to a second direct current, and the second Direct current is supplied to the starter motor to drive the crankshaft to rotate to the predetermined rotational speed by using the starter motor, wherein a voltage value of the second direct current is higher than a voltage value of the first direct current, and the microcontroller rotates at the crankshaft to reach the Stopping the boost control signal after the predetermined speed; and a step-down circuit for rotating the crankshaft to reach the predetermined speed Receiving a buck control signal of the microcontroller to step down an alternating current of one of the alternators of the engine into a third direct current, and charging the battery by using the third direct current, wherein the voltage value of the third direct current It is equal to the voltage value of the first direct current.

In an embodiment of the invention, the first direct current supplied by the battery has a voltage value of 12 volts.

In an embodiment of the invention, the voltage of the second direct current supplied to the starter motor of the boosting circuit is 48 volts.

In one embodiment of the invention, the alternating current of the alternator has a voltage value of 25 volts.

In an embodiment of the invention, the voltage of the third direct current generated by the step-down of the step-down circuit is 12 volts.

In an embodiment of the invention, the microcontroller, the boosting loop and the step-down loop of the control circuit are mounted on the same modular circuit board.

In an embodiment of the invention, the activation switch is selected from the group consisting of a start button, a brake switch, a main switch, or a combination thereof.

In one embodiment of the invention, the predetermined rotational speed is between 1500 and 1800 revolutions per minute (i.e., 1500-1800 rpm).

In an embodiment of the invention, the microcontroller issues the step-down control signal to the buck circuit after the crankshaft has rotated to the predetermined speed for a predetermined time to charge the battery. The predetermined time is, for example, 10 seconds or more.

In an embodiment of the present invention, the microcontroller further issues the step-down control signal to the step-down circuit after the brake switch is pressed and the crankshaft rotates below the predetermined speed for a predetermined time to the battery Charging. The predetermined time is, for example, 5 seconds or more.

In an embodiment of the invention, the boosting circuit includes an inductor coil, a field effect transistor (MOSFET), a Schottky barrier diode (SBD), and a capacitor.

In an embodiment of the invention, the step-down circuit comprises a voltage comparison loop, a field effect transistor, three controlled rectifiers (SCR), and three pairs of Schottky diodes; and the alternator of the engine includes a Group of three-phase coils.

The above and other objects, features and advantages of the present invention will become more <RTIgt; Furthermore, the directional terms mentioned in the present invention, such as "upper", "lower", "before", "after", "inside", "outside" or "side", are merely directions referring to the additional schema. . Therefore, the directional terminology used herein is for the purpose of illustration and understanding of the invention

Referring to Figures 2 and 3, the boost control device for the locomotive starter motor of the preferred embodiment of the present invention is mainly applied to a one-speed kerf type, off-road type or other type of locomotive to start a starter motor with power supply. 21, and then through a start gear set 22 and a start gear wheel 24 to drive a crankshaft 23 to rotate, so that a spark plug (not shown) of an engine 20 can be normally ignited to make the combustion chamber of the engine 20 (not It is shown that the combustion of oil and gas begins to start the engine 20 to start generating power.

As shown in the second and third embodiments, in the preferred embodiment of the present invention, the boost control device mainly includes a control circuit 25 electrically connected to a battery 26 and a starter motor 22 of the engine 20. between. Furthermore, the control circuit 25 and the battery 26 further comprise a main switch 27, which can be switched to open or closed by a key; at the same time, the control circuit 25 is electrically connected to at least one start switch, for example respectively It is electrically connected to a start button 28 and a brake switch 29 for respectively transmitting the start signal of the start button 28 and the brake switch 29 to the control circuit 25 by the rider. The main switch 27, the start button 28 and the brake switch 29 can be used as the start switch, which can be electrically connected to the control circuit 25 as shown in the second and third figures, respectively, or similar to the first one shown in FIG. The switches are connected in series to each other and then electrically connected to the control circuit 25.

It should be noted that although the driving motor 21 of the present invention drives the crankshaft 23 of the engine 20 to rotate in the same manner as the conventional starting motor 11 of FIG. 1, the difference between the two is that the starting motor 21 of the present invention The voltage specification is higher than the voltage specification of the battery 26, and the voltage specification (such as 12V) of the existing starter motor 11 is the same as the voltage specification of the existing battery 16 (such as 12V). In the preferred embodiment of the present invention, the voltage specification of the starter motor 21 of the present invention is preferably 48V, and the voltage specification of the battery 26 of the present invention is preferably 12V, but is not limited thereto, and the design of the voltage specification of the present invention is not limited thereto. The purpose will be described in detail below.

Referring to FIG. 3 again, the control circuit 25 of the preferred embodiment of the present invention is electrically connected between the battery 26 and the starter motor 21. The control circuit 25 mainly includes a microcontroller (MCU). 251, a boost circuit 252 and a buck circuit 253, wherein the microcontroller 251, the boost circuit 252 and the buck circuit 253 are preferably mounted on a surface mount technology (SMT). The same modular circuit board (such as a printed circuit board PCB) to reduce the overall volume, and thus easy to assemble in the appropriate position of the locomotive.

As shown in FIG. 3, the microcontroller 251 of the preferred embodiment of the present invention is a semiconductor package of an integrated circuit (IC) chip having a plurality of pins for respectively Other circuits or switches are electrically connected to receive external signals or to send out control signals. For example, in the preferred embodiment of the present invention, the microcontroller 251 is electrically connected to the battery 26, and can receive the first DC power supplied by the battery 26. The voltage of the first DC is preferably 12 Volt, and the microcontroller 251 can choose to directly use the first direct current, or first step down to a suitable voltage (for example, 5V) with a built-in step-down circuit.

Moreover, the microcontroller 251 can be configured to receive at least one start signal of at least one start switch (eg, the start button 28, the brake switch 29, and/or the main switch 27), and issue a boost immediately after receiving the start signal. Controlling the signal to control the boosting circuit 252 to perform a boosting operation; alternatively, the microcontroller 251 can also be used to issue a step-down control signal immediately after the crankshaft 23 is rotated to a predetermined rotational speed to control the step-down circuit. 253 performs the step-down and charging operation. The above-mentioned boost, buck and charge operations will be described in detail below.

As shown in FIGS. 3 and 3A, the booster circuit 252 of the preferred embodiment of the present invention is a circuit design composed of a plurality of SMT electronic components and circuit patterns on the modular circuit board. As shown in FIG. 3A, in the preferred embodiment of the present invention, the boosting circuit 252 preferably includes an inductor L, a field effect transistor (MOSFET) Q ₁ , and a Schottky barrier. Diode, SBD)D ₀ and a capacitor C, wherein one end of the inductor L is electrically connected to the anode of the battery 26, and the other end thereof is electrically connected to the drain of the field effect transistor Q ₁ and a p-side of the Schottky diode D ₀ ; a gate of the field effect transistor Q ₁ is electrically connected to the microcontroller 251, and a source thereof is electrically connected to the battery 26 a negative electrode, a negative electrode of the capacitor C and a negative electrode of the starter motor 21; an n-terminal of the Schottky diode D ₀ is electrically connected to a positive electrode of the capacitor C and a positive electrode of the starter motor 21; the capacitor C is preferably a capacitor Electrolyte capacitance. However, the boosting circuit 252 of the present invention is not limited thereto, and it may be a circuit having a boosting action by other electronic components.

In this embodiment, the boosting circuit 252 can receive the boost control signal of the microcontroller 251 and is activated by the control of the boost control signal to enable the battery 26 to supply a first direct current V _in The booster coil L and the field effect transistor Q _{1 are} boosted to a second direct current V _out , for example, when the voltage value of the first direct current V _in is 12 volts, the voltage of the second direct current V _out after boosting The value is preferably 48 volts, but is not limited thereto. As long as the voltage value of the second direct current V _out is higher than the voltage value of the first direct current V _in after boosting, it is a voltage value that can be implemented in the present invention.

Furthermore, after the boosting circuit 252 generates the second direct current V _out , the second direct current V _out output can be unidirectionally supplied to the capacitor C and the starter motor 21 through the Schottky diode D ₀ to The starter motor 21 that drives the same voltage specification (48V) provides sufficient and stable rotational torque to flexibly drive the crankshaft 23 to rotate to its predetermined rotational speed via the start gear set 22 and the starter gear plate 24, wherein the predetermined rotational speed is achieved. For example, between 1500 and 1800 revolutions per minute (ie, 1500-1800 rpm), but is not limited thereto.

As shown in FIG. 3, the step-down circuit 253 of the preferred embodiment of the present invention is a circuit design composed of a plurality of SMT electronic components and circuit patterns on the modular circuit board. For example, in the preferred embodiment of the present invention, the step-down circuit 253 preferably includes at least one voltage comparison loop 253a, a field effect transistor (MOSFET) Q ₂ , three step-controlled rectifiers SCR ₁ , SCR ₂ , and SCR. ₃ and three pairs of Xiaoji diodes D ₁₁ + D ₁₂ , D ₂₁ + D ₂₂ , D ₃₁ + D ₃₂ , wherein the voltage comparison loop 253a is an integrated circuit (IC) electrically connected to the battery a cathode of 26, a drain of the field effect transistor Q ₂ , a microcontroller 251, a gate of the three step-controlled rectifiers SCR ₁ , SCR ₂ , and SCR ₃ and a cathode of the battery 26; The gate of the effect transistor Q ₂ is electrically connected to the microcontroller 251, and the source thereof is electrically connected to the three pairs of Schottky diodes D ₁₁ +D ₁₂ , D ₂₁ +D ₂₂ , D ₃₁ +D The nth terminal of ₃₂ ; the cathodes of the three step-controlled rectifiers SCR ₁ , SCR ₂ , and SCR _{3 are} electrically connected to the negative electrode of the battery 26 , the voltage comparison circuit 253 a and the three pairs of the Schottky diode D _{11 + D 12, D 21 +} D 22, D 31 + D p of the end _32; the three silicon controlled rectifier SCR _1, SCR _2, SCR's anode ₃ (anode) are electrically connected to one of the engine 20 exchanges The first, second, third coil Y _1, Y _2, Y _3, and are electrically connected (the ACG) of three-phase coil of the motor 201 to a corresponding pair of Schottky diode D ₁₁ + D _12, D ₂₁ Between +D ₂₂ and D ₃₁ +D ₃₂ . However, the step-down circuit 253 of the present invention is not limited thereto, and it may be a circuit having a step-down effect by other electronic components.

In this embodiment, the step-down circuit 253 is mainly used to receive the step-down control signal sent by the microcontroller 251 by the voltage comparison circuit 253a after the crankshaft 23 rotates to the predetermined speed to make the engine 20 An alternating current (AC) generated by the first, second, and third coils Y ₁ , Y ₂ , and Y ₃ of the three-phase coil of the alternator 201 passes through the pair of Schottky diodes D ₁₁ + D ₁₂ , D ₂₁ +D ₂₂ , D ₃₁ +D ₃₂ for unidirectional rectification, and auxiliary unidirectional rectification via the three thyristor elements SCR ₁ , SCR ₂ , SCR ₃ , and finally controlled by the microcontroller 251 The field effect transistor Q ₂ depressurizes the rectified DC power into a third direct current (DC), and charges the battery 26 with the third direct current, wherein the voltage value of the third direct current is equal to the first The voltage value of the direct current, for example, the voltage value of the alternating current is set to 25 volts, and the voltage value of the third direct current is set to 12V, that is, the voltage value of the first direct current.

Referring to Figures 2, 3 and 3A again, when a motorcycle rider wants to use the boost control device of the locomotive starter motor of the preferred embodiment of the present invention to start the engine 20 of a locomotive, the battery 26 is pre-supplied. The first direct current (for example, 12V) is to the microcontroller 251 of the control circuit 25, but the microcontroller 251 is temporarily in a standby state. Then, the locomotive driver turns on the main switch 27 with a key, presses the brake switch 29 with one hand, and presses the start button 28 with the other hand, thereby generating at least one activation signal, so that the microcontroller 251 of the control circuit 25 is receiving Immediately after the start signal, a boost control signal is issued to control the boost circuit 252 to perform a boosting operation.

When boosting, the boosting circuit 252 receives the boosting control signal of the microcontroller 251, and is activated by the control of the boosting control signal to supply the first direct current (12V) of the battery 26 to rise. The pressure becomes a second direct current (for example, 48V). Thereafter, the second direct current unidirectional output is further supplied to the starter motor 21 to drive the starter motor 21 of the same voltage specification (48V) to provide sufficient and stable rotational torque for the starter gear set 22 to be activated. The gear plate 24 is flexibly driven to control the crankshaft 23 to rotate to its predetermined rotational speed (e.g., 1500-1800 rpm) or more.

It should be noted that once the locomotive rider activates the microcontroller 251 of the control circuit 25 via the start button 28 and/or the brake switch 29, even if the locomotive kiosk then manually releases the start button 28 and/or the brake switch 29, the micro The controller 251 can still control the starter motor 21 to continue to drive the crankshaft 23 of the engine 20 to rotate until a crankshaft speed detector 202 detects that the crankshaft 23 has rotated to the predetermined speed for a predetermined time (eg, 10 seconds or more). until. At the same time, during the boosting power supply of the boosting circuit 252, the microcontroller 251 does not issue a buck control signal, that is, the buck circuit 253 is in a standby state and has not been operated yet, thereby reducing the micro control. The load of the 251 is prevented, or the engine 20 is prevented from affecting the rotational speed of the crankshaft 23 by the alternator 201 generating electricity.

After the crankshaft speed detector 202 detects that the crankshaft 23 is rotated for a predetermined time (10 seconds or more), the spark plug (not shown) of the engine 20 has completed ignition to make the combustion chamber of the engine 20 (not drawn) Show) burning oil and gas, and driving the cylinder piston to generate power, so that the locomotive can run normally. Therefore, after a predetermined time, the microcontroller 251 immediately stops issuing the boost control signal to control the boost circuit 252 to stop the boosting operation, thereby stopping the supply of the second direct current to the starter motor 21, so that the starter motor 21 stops rotating. At the same time, the microcontroller 251 sends a step-down control signal to the step-down circuit 253 to step down the alternating current (for example, 25V-AC) of the alternator 201 of the engine 20 to the third stage by using the step-down circuit 253. Direct current (e.g., 12V-DC), and the battery 26 is charged using the third direct current. Furthermore, in another case, after the brake switch 29 is pressed and the crankshaft 23 of the engine 20 is rotated below the predetermined rotational speed (for example, 1500-1800 rpm) for a predetermined time (for example, 5 seconds or more), the micro control The 251 can also send the buck control signal to the buck loop 253 to charge the battery 26 with the buck loop 253.

As described above, the present invention in the second to third embodiments utilizes the microcontroller 251 to control the boosting circuit 252, which is the technical problem of the control device of the starter motor of the conventional Scooter type locomotive. 252 boosts the original voltage (12V) of the battery 26 and supplies it to the starter motor 21 of the higher voltage specification (48V) to perform flexible start control on the starter motor 21, since the starter motor 21 itself has a higher voltage specification. Sufficient and stable torque can be provided to the engine 20, so the starter motor 21 does not generate an instantaneous high current demand for the battery 26 at the moment of starting, thereby facilitating the start-up smoothness of starting the engine 20 and the vehicle power system and The stability of the engine ignition, and relatively reduce the starting noise and the degree of wear of the starting gear set 22.

Furthermore, in the present invention, once the locomotive rider activates the control circuit 25 via the start button 28 and the brake switch 29, even if the start button 28 and/or the brake switch 29 are subsequently manually released, the microcontroller of the control circuit 25 The booster circuit 252 can still control the starter motor 21 to continue to drive the crankshaft 23 of the engine 20 to rotate, and after the crankshaft 23 rotates for a predetermined time, immediately stop the booster circuit 252 to actuate to close the starter motor 21 Therefore, it is advantageous to improve starting efficiency and ease of operation, and to reduce the degree of wear of the battery 26.

Further, in the present invention, after the crankshaft 23 is rotated to a predetermined rotational speed (1500 to 1800 rpm) for a predetermined time (for example, 10 seconds or more), or when the brake switch 29 is pressed and the crankshaft 23 is rotated below a predetermined rotational speed, After a predetermined time (for example, 5 seconds or more), the step-down circuit 253 can be used to depressurize the alternating current (for example, 25V) of the alternator 201 of the engine 20 into a direct current (for example, 12V) to feedbackly charge the battery 20, During the operation of the boosting circuit 252, the microcontroller 251 also controls the buck circuit 253 to stop the charging operation, thereby facilitating effective control of the recharging voltage and ensuring startup efficiency.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

10. . . engine

11. . . start the motor

12. . . Start gear set

13. . . Crankshaft

14. . . Start gear wheel

15. . . Control circuit

151. . . start up button

152. . . Brake switch

153. . . Start relay

16. . . Battery

17. . . Main switch

20. . . engine

201. . . Alternator (ACG)

202. . . Crankshaft speed detector

twenty one. . . Starting motor (M)

twenty two. . . Start gear set

twenty three. . . Crankshaft

twenty four. . . Start gear wheel

25. . . Control circuit

251. . . Microcontroller

252. . . Boost loop

253. . . Buck loop

253a. . . Voltage comparison loop

26. . . Battery

27. . . Main switch

28. . . start up button

29. . . Brake switch

C. . . capacitance

D ₀ , D ₁₁ , D ₁₂ , D ₂₁ , D ₂₂ , D ₃₁ , D ₃₂ . . . Xiao Ji diode

L. . . Inductor coil

Q ₁ , Q ₂ . . . Field effect transistor

SCR ₁ , SCR ₂ , SCR ₃ . . . Voltage controlled rectifier

V _in . . . First direct current

V _out . . . Second direct current

Y ₁ , Y ₂ , Y ₃ . . . First, second, third coil

Fig. 1 is a schematic view showing a control device of a starter motor of a conventional Scooter type locomotive.

Figure 2 is a schematic view of a boost control device for a locomotive starter motor in accordance with a preferred embodiment of the present invention.

Figure 3 is a schematic illustration of a control circuit in accordance with a preferred embodiment of the present invention.

Figure 3A is a schematic illustration of a booster loop in accordance with a preferred embodiment of the present invention.

20. . . engine

201. . . Alternator

202. . . Crankshaft speed detector

twenty one. . . start the motor

25. . . Control circuit

251. . . Microcontroller

252. . . Boost loop

253. . . Buck loop

26. . . Battery

27. . . Main switch

28. . . start up button

29. . . Brake switch

Claims (7)

A boosting control device for a locomotive starting motor, comprising a control circuit electrically connected between a battery and a starting motor, the starting motor for starting an engine, wherein the control circuit comprises: a microcontroller Electrically connected to the battery, the microcontroller is configured to issue a boost control signal after receiving at least one start signal of the at least one start switch; or to send a crankshaft after the engine reaches a predetermined speed a step-down control signal; a boosting circuit receiving the boost control signal to boost a first direct current of the battery supply to a second direct current, and supplying the second direct current to the starter motor to utilize The starter motor drives the crankshaft to rotate to the predetermined speed, wherein the voltage of the second direct current is higher than the voltage of the first direct current, and the microcontroller stops issuing the boost after the crankshaft reaches the predetermined speed a control signal, wherein the boosting circuit comprises an inductor coil, a field effect transistor, a Schottky diode, and a capacitor; a step-down loop for receiving a step-down control signal of the microcontroller after the crankshaft rotates to reach the predetermined speed, so as to step down an alternating current of one of the alternators of the engine into a third direct current, and utilize the The third direct current charges the battery, wherein the voltage value of the third direct current is equal to the voltage value of the first direct current, wherein the step-down circuit comprises a voltage comparison loop, a field effect transistor, three voltage controlled rectifiers, and three pairs of Xiao a base diode; and the alternator of the engine includes a set of three-phase coils; The microcontroller, boost circuit and step-down circuit of the control circuit are mounted on the same modular circuit board. The boosting control device for the locomotive starting motor according to the first aspect of the invention, wherein the voltage value of the first direct current supplied by the battery and the voltage value of the third direct current generated by the step-down of the buck circuit are both 12 volts. A boost control device for a locomotive starter motor according to claim 1 or 2, wherein a voltage value of the second direct current supplied to the starter motor of the booster circuit is 48 volts. The boost control device for a locomotive starter motor according to claim 1, wherein the start switch is selected from the group consisting of a start button, a brake switch, a main switch, or a combination thereof. The boost control device for a locomotive starter motor according to claim 1, wherein the predetermined rotational speed is between 1500 and 1800 revolutions per minute. The boost control device for a locomotive starter motor according to claim 5, wherein the microcontroller sends the step-down control signal to the step-down circuit after the crankshaft rotates to the predetermined speed for a predetermined time. Charging the battery; wherein the predetermined time is 10 seconds or more. The boost control device for the locomotive starter motor of claim 5, wherein the microcontroller issues the buck control signal after the brake switch is pressed and the crankshaft rotates below the predetermined rotational speed for a predetermined time. Up to the buck circuit to charge the battery; The predetermined time is, for example, 5 seconds or more.