A forward and reverse rotation module based on power supply polarity control

Abstract

This invention discloses a forward / reverse control module based on power supply polarity control, comprising a power supply circuit, an interlock delay circuit, a drive circuit, a switching circuit, a detection circuit, and an external brake signal input terminal. The drive circuit is connected in series between the interlock delay circuit and the switching circuit, and the switching circuit is connected in series between the load power supply and the winding terminals of the motor. The signal input terminal of the detection circuit is connected to the switching circuit to detect the positive and negative directions of the input voltage of the load power supply. The external brake signal input terminal is connected to the drive circuit through the detection circuit, and an interlock switch is connected between the external brake signal input terminal and the detection circuit. The output terminal of the interlock delay circuit is connected to the interlock switch to control its on / off state. This invention combines forward / reverse control and braking functions without requiring additional braking components, can autonomously adjust the braking time, and features a simple braking structure, excellent braking performance, and high reliability.

Description

Technical Field

[0001] This invention relates to the field of three-phase motor forward and reverse rotation control technology, and in particular to a forward and reverse rotation module based on power supply polarity control. Background Technology

[0002] A three-phase motor is an AC motor driven by three-phase alternating current. The principle of three-phase motor rotation is as follows: When three-phase electricity is applied to the motor, the stator generates a rotating magnetic field under the influence of the three-phase electricity. This magnetic field creates a relative cutting motion with the rotor, inducing an electromotive force and generating an inductive current in the rotor conductors. The current-carrying rotor conductors experience an electromagnetic force in the magnetic field, forming an electromagnetic torque that drives the rotor to rotate. The direction of rotor rotation is related to the direction of the magnetic field, which in turn is related to the phase sequence of the three-phase electricity. By switching the phase sequence of the three-phase power supply, the direction of motor rotation can be controlled. A three-phase motor forward / reverse module can be used to switch the phase sequence of the three-phase electricity, thereby controlling the direction of motor rotation.

[0003] If three-phase electricity is replaced with direct current, the magnetic field generated by the motor stator will be a constant direction magnetic field, which will hinder the rotation of the motor rotor and create a braking effect.

[0004] Currently, most forward and reverse rotation modules used for three-phase motor control can only control the forward and reverse rotation of three-phase motors. Their main components are interlocking delay circuits, optocoupler isolation circuits, and power component circuits. If braking is required, reverse braking or an external braking assembly is typically used. However, reverse braking has lower accuracy and is prone to failure to stop or over-braking leading to reverse rotation. External braking assemblies are more complex and expensive.

[0005] Some forward and reverse rotation modules have braking functions. For example, CN201820080042.4, "A Three-Phase Motor Forward and Reverse Rotation Controller with DC Braking," can achieve good braking performance. However, the control circuit is complex and costly. This solution uses a three-phase power supply rectified into DC power by diodes, and then controlled by IGBTs using PWM to keep the current through the motor constant, creating a constant magnetic field inside the motor to prevent rotation and achieve a braking effect. Because braking and forward / reverse rotation are independent and cannot work simultaneously, they need to be separated by a switch, placing high demands on the product's control timing.

[0006] In view of this, the inventors have developed a forward and reverse rotation module based on power polarity control, which has forward and reverse rotation control function and braking function. Summary of the Invention

[0007] The purpose of this invention is to provide a forward and reverse rotation module based on power polarity control. By adding a braking function to a conventional forward and reverse rotation module, the module can have both forward and reverse rotation control and braking functions without the need for additional braking components. It can also adjust the braking time autonomously and features a simple braking structure, excellent braking performance, and high reliability.

[0008] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0009] A forward / reverse module based on power polarity control includes a power supply circuit, an interlock delay circuit, a drive circuit, a switching circuit, a detection circuit, and an external brake signal input terminal.

[0010] The interlock delay circuit has a forward rotation signal input terminal and a reverse rotation signal input terminal. The drive circuit is connected in series between the interlock delay circuit and the switching circuit. The switching circuit is connected in series between the load power supply and the winding assembly terminal of the motor, forming a forward and reverse rotation power supply control circuit for the motor.

[0011] The signal input terminal of the detection circuit is connected to the switching circuit to detect the positive and negative directions of the input voltage of the load power supply.

[0012] The external brake signal input terminal is connected to the drive circuit through the detection circuit. An interlock switch is connected between the external brake signal input terminal and the detection circuit. The output terminal of the interlock delay circuit is connected to the interlock switch to control its on / off state. When the interlock delay circuit does not receive a forward or reverse signal, the interlock switch is closed, and the external brake signal input terminal is connected to the detection circuit. The detection circuit obtains the brake signal from the external brake signal input terminal and distributes it to the drive circuit. The drive circuit drives the corresponding switch in the switching circuit to conduct according to the brake signal, so as to form a rectifier circuit that rectifies the AC power input from the load power supply into DC power, so that the motor is braked by the constant direction magnetic field generated by the DC power.

[0013] Furthermore, the interlock delay circuit includes a forward rotation output terminal F_S, a forward rotation interlock output terminal F_L, a reverse rotation output terminal R_S, and a reverse rotation interlock output terminal R_L; the drive circuit includes drive switches T1, T3, T5, interlock switches T2, and T4; the switch circuit includes a first switch K1 connected between the load power output line L1 and the winding group terminal U, a second switch K2 connected between the load power output line L2 and the winding group terminal U, a third switch K3 connected between the load power output line L1 and the winding group terminal V, a fourth switch K4 connected between the load power output line L2 and the winding group terminal V, and a fifth switch K5 connected between the load power output line L3 and the winding group terminal W.

[0014] The forward rotation output terminal F_S is connected in sequence to drive switch T1, optocoupler PX1 and PX4; the forward rotation interlock output terminal F_L is connected in sequence to interlock switch T4 and drive switch T3; the reverse rotation output terminal R_S is connected in sequence to drive switch T3, optocoupler PX2 and PX3; the reverse rotation interlock output terminal R_L is connected in sequence to interlock switch T2 and drive switch T1; the forward rotation output terminal F_S is also connected in sequence to drive switch T5 and optocoupler PX5; the reverse rotation output terminal R_S is also connected in sequence to drive switch T5 and optocoupler PX5.

[0015] When the forward output terminal F_S outputs a high level, the activated drive switch T1 controls the first switch K1 and the fourth switch K4 to conduct through optocouplers PX1 and PX4 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate forward; when the reverse output terminal R_S outputs a high level, the activated drive switch T3 controls the second switch K2 and the third switch K3 to conduct through optocouplers PX2 and PX3 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate in reverse.

[0016] When the forward interlock output terminal F_L outputs a high level, the interlock switch T4 is turned on and the drive switch T3 is turned off; or when the reverse interlock output terminal R_L outputs a high level, the interlock switch T2 is turned on and the drive switch T1 is turned off, thus achieving interlocking.

[0017] Furthermore, the detection circuit employs a power supply polarity detection circuit; the power supply polarity detection circuit includes optocoupler P1 and optocoupler P2, the input terminals of optocoupler P1 and optocoupler P2 are connected in antiparallel to the load power output line L1 and the load power output line L2; the external brake signal input terminal is connected to drive switch T3 through optocoupler P1 and to drive switch T1 through optocoupler P2;

[0018] When a brake signal is input to the external brake signal input terminal, if the voltage of the load power output line L1 is greater than that of the load power output line L2, the brake signal is output to the drive circuit through the optocoupler P1, controlling the drive switch T3 to turn on and the drive switch T1 to turn off. This, in turn, controls the second switch K2 and the third switch K3 to turn on, and the first switch K1 and the fourth switch K4 to turn off. This allows the optocoupler P1 to be connected in parallel with the second switch K2 and the third switch K3, forming a first current loop with the second switch K2, the third switch K3, the winding group terminal U, and the winding group terminal V. If the voltage of the load power output line L2 is greater than that of the load power output line L1, the brake signal is output to the drive circuit through the optocoupler P2, controlling the drive switch T1 to turn on and the drive switch T3 to turn off. This, in turn, controls the first switch K1 and the fourth switch K4 to turn on, and the second switch K2 and the third switch K3 to turn off. This allows the optocoupler P2 to be connected in parallel with the first switch K1 and the fourth switch K4, forming a second current loop with the first switch K1, the fourth switch K4, the winding group terminal U, and the winding group terminal V.

[0019] Furthermore, the drive switch T1, interlock switch T2, drive switch T3, interlock switch T4, drive switch T5, and the interlock switch T6 connected between the external brake signal input terminal and the detection circuit are all switching transistors or MOSFETs.

[0020] Furthermore, the module also includes a first step-down circuit connected in series between the external brake signal input and the interlock switch.

[0021] Furthermore, the module also includes a second buck circuit connected in series between the power supply circuit and the input of the interlock delay circuit.

[0022] After adopting the above scheme, the overall principle of the present invention to realize forward and reverse rotation control and braking function is as follows:

[0023] The interlock delay circuit is used to receive forward and / or reverse signals, and the detection circuit is used to detect the positive and negative directions of the input voltage of the load power supply. When the interlock delay circuit does not receive a forward or reverse signal, the interlock switch is closed, and the external brake signal input terminal is connected to the detection circuit. The detection circuit obtains the brake signal from the external brake signal input terminal and distributes it to the drive circuit. The drive circuit drives the corresponding switch in the switching circuit to turn on according to the brake signal. Specifically, when the corresponding switch in the drive circuit is turned on, the forward and reverse power supply control circuit can be switched to a DC circuit to form a rectifier circuit that rectifies the AC power input of the load power supply into DC power, so that the motor is braked by the constant direction magnetic field generated by the DC power.

[0024] When the interlock delay circuit has a forward or reverse signal, the interlock switch is turned on, and the external brake signal input terminal is not connected to the detection circuit. The external brake signal cannot be transmitted to the drive circuit. At this time, the interlock delay circuit directly outputs the forward / reverse control command to the drive circuit according to the forward or reverse signal. The drive circuit controls the corresponding switch in the switching circuit to turn on, so that the forward and reverse power supply control loop can be switched to forward / reverse, realizing forward and reverse control.

[0025] When the interlock delay circuit has both forward and reverse signals, the interlock switch is turned on, and the external brake signal input terminal is not connected to the detection circuit. The interlock delay circuit directly outputs the interlock control command based on the forward and reverse signals. The drive circuit cannot drive the switch in the control switch circuit to turn on, thus achieving interlock.

[0026] The present invention has the following beneficial effects:

[0027] I. This invention detects the positive and negative direction information of the load power supply input voltage through a detection circuit. An interlock delay circuit controls the on / off state of the interlock switch based on the presence / absence of forward and reverse rotation signals. Combining these two pieces of information, under the condition that both forward and reverse rotation signals are simultaneously absent, the interlock switch is activated. The user can input a braking signal to the detection circuit via an external signal input terminal. The detection circuit then distributes the braking signal to the drive module. The drive module, by controlling the power switch of the switching circuit, rectifies the AC power, creating a magnetic field in a constant direction on the motor rotor, thereby hindering the rotation of the motor rotor and achieving a braking effect.

[0028] Second, the brake signal is provided externally, and users can set the braking time at will, but cannot adjust the braking force.

[0029] Third, the forward and reverse rotation module of the present invention does not require the use of the complex structure of existing forward and reverse rotation control and DC braking circuits. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other modifications can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the forward and reverse rotation module circuit structure based on power supply polarity control according to an embodiment of the present invention;

[0032] Label Explanation

[0033] The circuit includes a power supply circuit 10, an interlock delay circuit 20, a drive circuit 30, a switch circuit 40, a detection circuit 50, a first step-down circuit 60, and a second step-down circuit 70. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] like Figure 1 As shown in the figure, an embodiment of the present invention discloses a forward and reverse rotation module based on power polarity control, including a power supply circuit 10, an interlock delay circuit 20, a drive circuit 30, a switch circuit 40, a detection circuit 50, and an external brake signal input terminal B+.

[0036] The interlock delay circuit 20 has a forward rotation signal input terminal F+ and a reverse rotation signal input terminal R+. The drive circuit 30 is connected in series between the interlock delay circuit 20 and the switching circuit 40. The switching circuit 40 is connected in series between the load power supply and the winding assembly terminals of the motor, forming a forward and reverse rotation power supply control circuit for the motor. In this embodiment, the interlock delay circuit 20 further includes a forward rotation output terminal F_S, a forward rotation interlock output terminal F_L, a reverse rotation output terminal R_S, and a reverse rotation interlock output terminal R_L. The drive circuit 30 includes a drive switch T1 and a drive... The circuit includes a first switch K1 connected between the load power output line L1 and the winding group terminal U, a second switch K2 connected between the load power output line L2 and the winding group terminal U, a third switch K3 connected between the load power output line L1 and the winding group terminal V, a fourth switch K4 connected between the load power output line L2 and the winding group terminal V, and a fifth switch K5 connected between the load power output line L3 and the winding group terminal W.

[0037] The forward rotation output terminal F_S is connected in sequence to drive switch T1, optocoupler PX1 and PX4; the forward rotation interlock output terminal F_L is connected in sequence to interlock switch T4 and drive switch T3; the reverse rotation output terminal R_S is connected in sequence to drive switch T3, optocoupler PX2 and PX3; the reverse rotation interlock output terminal R_L is connected in sequence to interlock switch T2 and drive switch T1; the forward rotation output terminal F_S is also connected in sequence to drive switch T5 and optocoupler PX5; the reverse rotation output terminal R_S is connected in sequence to drive switch T5 and optocoupler PX5.

[0038] Based on the above circuit structure, the forward and reverse rotation control and interlocking principle implemented by the forward and reverse mounting module of the present invention are as follows:

[0039] When the interlock delay circuit 20 receives the forward rotation signal, when the forward rotation output terminal F_S outputs a high level, the activated drive switch T1 controls the first switch K1 and the fourth switch K4 to be activated through optocoupler PX1 and optocoupler PX4 respectively, and the activated drive switch T5 controls the fifth switch K5 to be activated through optocoupler PX5, and the motor rotates forward.

[0040] When the interlock delay circuit 20 receives the reversal signal, when the reversal output terminal R_S outputs a high level, the activated drive switch T3 controls the second switch K2 and the third switch K3 to be activated through optocoupler PX2 and optocoupler PX3 respectively, and the activated drive switch T5 controls the fifth switch K5 to be activated through optocoupler PX5, and the motor reverses.

[0041] When the interlock delay circuit 20 receives the forward rotation signal and the reverse rotation signal, the forward rotation interlock output terminal F_L outputs a high level, the interlock switch T4 is turned on, and the drive switch T3 is turned off. Alternatively, when the reverse rotation interlock output terminal R_L outputs a high level, the interlock switch T2 is turned on, and the drive switch T1 is turned off, thus achieving interlocking.

[0042] The signal input terminal of the detection circuit 50 is connected to the switching circuit 40 to detect the positive and negative directions of the input voltage of the load power supply.

[0043] The external brake signal input terminal B+ is connected to the drive circuit 30 through the detection circuit 50. An interlock switch T6 is connected between the external brake signal input terminal B+ and the detection circuit 50. The output terminal of the interlock delay circuit 20 is connected to the interlock switch T6 to control its on / off state. When the interlock delay circuit 20 does not receive a forward or reverse rotation signal, the interlock switch T6 is turned off, and the detection circuit 50 is connected to the brake signal input terminal B+. The detection circuit 50 obtains the brake signal from the external brake signal input terminal B+ and distributes it to the drive circuit 30. The drive circuit 30 drives the corresponding switch in the switch circuit 40 to turn on according to the brake signal, so as to form a rectifier circuit that rectifies the AC power input from the load power supply into DC power, so that the motor is braked by the constant direction magnetic field generated by the DC power.

[0044] In this embodiment, preferably, the detection circuit 50 adopts a power supply polarity detection circuit; the power supply polarity detection circuit includes optocoupler P1 and optocoupler P2, which are connected in parallel to the load power output line L1 and the load power output line L2, respectively; the external brake signal input terminal B+ is connected to the drive switch T3 through optocoupler P1 and to the drive switch T1 through optocoupler P2.

[0045] Based on the above circuit structure, the braking principle of the forward and reverse rotation module in this embodiment is as follows: When the interlock delay circuit 20 does not receive a forward or reverse rotation signal, the interlock switch T6 is turned off, and the detection circuit 50 is connected to the brake signal input terminal B+. The detection circuit 50 obtains the brake signal from the external brake signal input terminal B+ and distributes it to the drive circuit 30. That is, when the external brake signal input terminal B+ inputs a brake signal, if the detection circuit 50 detects that the voltage of the load power output line L1 is greater than that of the load power output line L2, the brake signal is output to the drive circuit 30 through the optocoupler P1, controlling the drive switch T3 to turn on and the drive switch T1 to turn off, thereby controlling the second switch K2 and the third switch K3 to turn on. When the first switch K1 and the fourth switch K4 are turned off, the optocoupler P1 is connected in parallel with the second switch K2 and the third switch K3, forming a first current loop with the second switch K2, the third switch K3, the winding group terminal U, and the winding group terminal V. If the voltage of the load power output line L2 is greater than that of the load power output line L1, the braking signal is output to the drive circuit 30 through the optocoupler P2, controlling the drive switch T1 to turn on and the drive switch T3 to turn off, thereby controlling the first switch K1 and the fourth switch K4 to turn on and the second switch K2 and the third switch K3 to turn off, so that the optocoupler P2 is connected in parallel with the first switch K1 and the fourth switch K4, forming a second current loop with the first switch K1, the fourth switch K4, the winding group terminal U, and the winding group terminal V. Regardless of whether the voltage of the load power output line L1 or the voltage of the load power output line L2 is greater, the winding group terminal U maintains a positive voltage and the winding group terminal V maintains a negative voltage. That is, in both the first current loop and the second circuit loop, the winding group terminal U is positive and the winding group terminal V is negative. This voltage causes the motor rotor to generate a constant magnetic field with an unchanged direction, thereby suppressing the motor rotation and producing a braking effect. This control process can also prevent the forward switch (first switch K1, fourth switch K4) and the reverse switch (second switch K2, third switch K3) from being turned on at the same time, realizing the interlock protection function and preventing the components from burning out.

[0046] As a further preferred embodiment, the interlock switch T6, drive switch T1, interlock switch T2, drive switch T3, interlock switch T4, and drive switch T5 are all switching transistors or MOSFETs.

[0047] As a further preferred embodiment, the module also includes a first step-down circuit 60 connected in series between the external brake signal input terminal B+ and the interlock switch T6, and a second step-down circuit 70 connected in series between the power supply circuit 10 and the input terminal of the interlock delay circuit 20. The switching circuit 40 may include a capacitor and a varistor. The capacitor may also be a RC circuit to protect the power switch.

[0048] The embodiments described above do not constitute a limitation on the scope of protection of this technical solution. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the above embodiments should be included within the scope of protection of this technical solution.

Claims

1. A forward / reverse module based on power supply polarity control, characterized in that: It includes a power supply circuit, an interlock delay circuit, a drive circuit, a switching circuit, a detection circuit, and an external brake signal input terminal; The interlock delay circuit has a forward rotation signal input terminal and a reverse rotation signal input terminal. The drive circuit is connected in series between the interlock delay circuit and the switching circuit. The switching circuit is connected in series between the load power supply and the winding assembly terminal of the motor, forming a forward and reverse rotation power supply control circuit for the motor. The signal input terminal of the detection circuit is connected to the load power supply to detect the positive and negative directions of the input voltage of the load power supply. The external brake signal input terminal is connected to the drive circuit through the detection circuit. An interlock switch is connected between the external brake signal input terminal and the detection circuit. The output terminal of the interlock delay circuit is connected to the interlock switch to control its on / off state. When the interlock delay circuit does not receive a forward or reverse signal, the interlock switch is closed, and the external brake signal input terminal is connected to the detection circuit. The detection circuit obtains the brake signal from the external brake signal input terminal and distributes it to the drive circuit. The drive circuit drives the corresponding switch in the switching circuit to conduct according to the brake signal, so as to form a rectifier circuit that rectifies the AC power input from the load power supply into DC power, so that the motor is braked by the constant direction magnetic field generated by the DC power. The detection circuit adopts a power supply polarity detection circuit; the power supply polarity detection circuit includes optocoupler P1 and optocoupler P2, the input terminals of optocoupler P1 and optocoupler P2 are connected in antiparallel to the load power output line L1 and the load power output line L2; the external brake signal input terminal is connected to drive switch T3 through optocoupler P1 and to drive switch T1 through optocoupler P2. When a brake signal is input to the external brake signal input terminal, if the voltage of the load power output line L1 is greater than that of the load power output line L2, the brake signal is output to the drive circuit through the optocoupler P1, controlling the drive switch T3 to turn on and the drive switch T1 to turn off. This, in turn, controls the second switch K2 and the third switch K3 to turn on, and the first switch K1 and the fourth switch K4 to turn off. This allows the optocoupler P1 to be connected in parallel with the second switch K2 and the third switch K3, forming a first current loop with the second switch K2, the third switch K3, the winding group terminal U, and the winding group terminal V. If the voltage of the load power output line L2 is greater than that of the load power output line L1, the brake signal is output to the drive circuit through the optocoupler P2, controlling the drive switch T1 to turn on and the drive switch T3 to turn off. This, in turn, controls the first switch K1 and the fourth switch K4 to turn on, and the second switch K2 and the third switch K3 to turn off. This allows the optocoupler P2 to be connected in parallel with the first switch K1 and the fourth switch K4, forming a second current loop with the first switch K1, the fourth switch K4, the winding group terminal U, and the winding group terminal V.

2. The forward and reverse rotation module based on power supply polarity control as described in claim 1, characterized in that: The interlocking delay circuit includes a forward rotation output terminal F_S, a forward rotation interlocking output terminal F_L, a reverse rotation output terminal R_S, and a reverse rotation interlocking output terminal R_L. The driving circuit includes a driving switch T1, a driving switch T3, a driving switch T5, an interlocking switch T2, and an interlocking switch T4. The switching circuit includes a first switch K1 connected between the load power output line L1 and the winding group terminal U, a second switch K2 connected between the load power output line L2 and the winding group terminal U, a third switch K3 connected between the load power output line L1 and the winding group terminal V, a fourth switch K4 connected between the load power output line L2 and the winding group terminal V, and a fifth switch K5 connected between the load power output line L3 and the winding group terminal W. The forward rotation output terminal F_S is connected in sequence to drive switch T1, optocoupler PX1 and PX4; the forward rotation interlock output terminal F_L is connected in sequence to interlock switch T4 and drive switch T3; the reverse rotation output terminal R_S is connected in sequence to drive switch T3, optocoupler PX2 and PX3; the reverse rotation interlock output terminal R_L is connected in sequence to interlock switch T2 and drive switch T1; the forward rotation output terminal F_S is also connected in sequence to drive switch T5 and optocoupler PX5; the reverse rotation output terminal R_S is also connected in sequence to drive switch T5 and optocoupler PX5. When the forward output terminal F_S outputs a high level, the activated drive switch T1 controls the first switch K1 and the fourth switch K4 to conduct through optocouplers PX1 and PX4 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate forward; when the reverse output terminal R_S outputs a high level, the activated drive switch T3 controls the second switch K2 and the third switch K3 to conduct through optocouplers PX2 and PX3 respectively, and the activated drive switch T5 controls the fifth switch K5 to conduct through optocoupler PX5, causing the motor to rotate in reverse. When the forward interlock output terminal F_L outputs a high level, the interlock switch T4 is turned on and the drive switch T3 is turned off; or when the reverse interlock output terminal R_L outputs a high level, the interlock switch T2 is turned on and the drive switch T1 is turned off, thus achieving interlocking.

3. The forward and reverse rotation module based on power supply polarity control as described in claim 2, characterized in that: The drive switch T1, interlock switch T2, drive switch T3, interlock switch T4, drive switch T5, and the interlock switch T6 connected between the external brake signal input terminal and the detection circuit all use switching transistors or MOSFETs.

4. The forward and reverse rotation module based on power supply polarity control as described in claim 1, characterized in that: The module also includes a first step-down circuit connected in series between the external brake signal input and the interlock switch.

5. A forward / reverse module based on power supply polarity control as described in claim 1, characterized in that: The module also includes a second buck circuit connected in series between the power supply circuit and the input of the interlock delay circuit.

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