Novel H-bridge circuit

Abstract

The utility model relates to a novel H bridge circuit, comprising a motor diagnosis circuit and a motor driving circuit, the motor diagnosis circuit comprises three resistors, and the three resistors form a resistor voltage dividing network; the motor driving circuit comprises two PMOS (P-channel Metal Oxide Semiconductor) tubes and two NMOS (N-channel Metal Oxide Semiconductor) tubes, and the motor driving circuit can detect the voltage condition at the two ends of the motor by utilizing a resistance potential-divider network, so as to judge whether the motor is in a normal state or not. Specifically, by applying a test voltage to the motor and measuring the voltage difference between the two ends of the motor, the resistance value of a motor coil can be indirectly evaluated, and if the resistance value is abnormal, it is indicated that the motor may have a fault. According to the circuit design of the utility model, state inspection can be carried out before the motor is started, and the situation of running with diseases is effectively prevented. And as the simple resistance potential-divider network is adopted to preliminarily judge the state of the motor, the whole diagnosis process is very rapid, and the starting time of the system is not obviously prolonged.

Description

Technical Field

[0001] This utility model relates to motor drive circuits, and in particular to a novel H-bridge circuit. Background Technology

[0002] Existing H-bridge circuits are primarily used for driving motors in both forward and reverse directions, controlling motor start-up, stopping, and direction by manipulating switches (such as MOSFETs) in the bridge arms. However, these circuits typically lack diagnostic capabilities for motor status, failing to detect whether the motor is functioning correctly before startup. This can lead to attempts to start a motor that is already damaged, potentially causing safety hazards or equipment damage.

[0003] Currently, although some motor protection circuits can monitor parameters such as current or temperature during motor operation, these methods typically cannot perform a comprehensive condition check before motor startup. Therefore, developing an H-bridge circuit capable of performing condition diagnosis before motor startup is of significant practical importance in addressing the aforementioned technical issues. Utility Model Content

[0004] This invention proposes a novel H-bridge circuit capable of performing status diagnosis before motor startup, thus solving the aforementioned problems existing in the prior art.

[0005] The technical solution of this utility model is implemented as follows: a novel H-bridge circuit includes a motor diagnostic circuit and a motor drive circuit. The motor diagnostic circuit includes three resistors, which form a resistor divider network. The motor drive circuit includes two PMOS transistors and two NMOS transistors.

[0006] Preferably, the motor diagnostic circuit includes:

[0007] Resistor R1, the first end of which is connected to an external diagnostic power supply, and the second end of which is connected to the positive terminal of the motor;

[0008] Resistor R2, the first end of which is connected to the negative terminal of the motor, and the second end of which is connected to the diagnostic feedback point;

[0009] Resistor R3, the first end of which is connected to the second end of resistor R2, and the second end of resistor R3 is grounded.

[0010] Preferably, the motor drive circuit includes:

[0011] PMOS transistor Q1, the source S of which is connected to an external DC power supply, the gate G of which is connected to the forward rotation upper arm control signal, and the drain D of which is connected to the positive terminal of the motor;

[0012] PMOS transistor Q2, the source S of which is connected to an external DC power supply, the gate G of which is connected to an inverted upper arm control signal, and the drain D of which is connected to the negative terminal of the motor;

[0013] NMOS transistor Q3, the source S of which is grounded, the gate G of which is connected to the inverted lower arm control signal, and the drain D of which is connected to the positive terminal of the motor;

[0014] NMOS transistor Q4, the source S of which is grounded, the gate G of which is connected to the forward rotation lower arm control signal, and the drain D of which is connected to the negative terminal of the motor.

[0015] In summary, the beneficial effects of this utility model are as follows:

[0016] 1. This invention utilizes a resistor voltage divider network to detect the voltage across the motor, thereby determining whether the motor is in a normal operating state. Specifically, by applying a test voltage to the motor and measuring the voltage difference across its terminals, the resistance value of the motor coil can be indirectly evaluated. If the resistance value is abnormal, it indicates a potential motor malfunction. Furthermore, this invention employs a standard H-bridge structure composed of two PMOS transistors and two NMOS transistors to control the motor's forward and reverse rotation. The PMOS transistors act as high-side switches, and the NMOS transistors as low-side switches, using different combinations of control signals to achieve forward, reverse, or stop operation. This circuit design allows for status checks before motor startup, effectively preventing operation with faulty components. Because a simple resistor voltage divider network is used for preliminary motor status assessment, the entire diagnostic process is very rapid and does not significantly increase system startup time. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model. Detailed Implementation

[0019] The following will refer to the appendix in the embodiments of this utility model. Figure 1The technical solutions in the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] Example:

[0021] like Figure 1 As shown, this utility model discloses a novel H-bridge circuit, including a motor diagnostic circuit and a motor drive circuit. The motor diagnostic circuit is used to diagnose the state of the motor before driving the motor. The motor diagnostic circuit includes three resistors that form a resistor divider network. The motor drive circuit is used to control the forward and reverse rotation of the motor. The motor drive circuit includes two PMOS transistors and two NMOS transistors.

[0022] Specifically, the motor diagnostic circuit includes:

[0023] Resistor R1, with its first end connected to an external diagnostic power supply and its second end connected to the positive terminal of the motor;

[0024] Resistor R2, the first end of resistor R2 is connected to the negative terminal of the motor, and the second end of resistor R2 is connected to the diagnostic feedback point;

[0025] Resistor R3, the first end of resistor R3 is connected to the second end of resistor R2, and the second end of resistor R3 is grounded.

[0026] The motor drive circuit specifically includes:

[0027] PMOS transistor Q1, with its source S connected to an external DC power supply, its gate G connected to the forward rotation upper arm control signal, and its drain D connected to the positive terminal of the motor.

[0028] PMOS transistor Q2, with its source S connected to an external DC power supply, its gate G connected to the inverting upper arm control signal, and its drain D connected to the negative terminal of the motor.

[0029] NMOS transistor Q3, with its source S grounded, its gate G connected to the inverting lower arm control signal, and its drain D connected to the positive terminal of the motor.

[0030] NMOS transistor Q4 has its source (S) grounded, its gate (G) connected to the forward rotation lower arm control signal, and its drain (D) connected to the negative terminal of the motor.

[0031] The motor diagnostic circuit of this invention determines the coil impedance of the motor by measuring the voltage difference across the motor terminals, thereby diagnosing the motor's condition. The motor drive circuit controls the conduction states of PMOS transistors Q1, Q2, Q3, and Q4 to achieve forward and reverse rotation of the motor. The motor diagnostic circuit performs a status check before starting the motor to ensure it is in normal operating condition before starting the motor.

[0032] Furthermore, this embodiment also discloses a motor control system using the novel H-bridge circuit, comprising:

[0033] The power module is used to provide external DC power and external diagnostic power.

[0034] The control module is used to generate forward rotation upper arm control signals, reverse rotation upper arm control signals, forward rotation lower arm control signals, and reverse rotation lower arm control signals.

[0035] The display module is used to display motor diagnostic results and operating status.

[0036] The control module specifically includes a diagnostic control unit, which is used to activate the motor diagnostic circuit before the motor starts, obtain diagnostic results, and decide whether to start the motor based on the diagnostic results.

[0037] The display module specifically includes indicator lights or a display screen, which is used to intuitively display the diagnostic results and operating status of the motor.

[0038] The specific workflow of this utility model is as follows:

[0039] I. The working principle of the motor diagnostic circuit is as follows:

[0040] 1. Diagnostic power-on:

[0041] When motor diagnostics are required, a known diagnostic voltage (Vd) is first provided to one end of resistor R1.

[0042] 2. Voltage division:

[0043] Resistor R1 and the motor coil form a voltage divider network. Assuming the impedance of the motor coil is Zm, the voltage (Vm+) at the positive terminal of the motor can be calculated using the following formula: V m+ =V d ·Z m / (R1+Z m ).

[0044] 3. Motor status detection:

[0045] The voltage at the negative terminal of the motor (Vm-) is directly grounded, so its voltage is 0V. At this time, through another voltage divider network formed by resistors R2 and R3, a voltage (Vf) reflecting the motor's condition can be measured at the node between R2 and R3 (i.e., the diagnostic feedback point). This voltage Vf is related to the impedance Zm of the motor coil. If the motor coil is short-circuited or open-circuited, Vf will deviate significantly from the normal value.

[0046] 4. Analysis of diagnostic results:

[0047] The voltage Vf at the diagnostic feedback point can be used to determine whether the motor is in a normal state. For example, if Vf is much lower than the expected value, it may indicate a short circuit in the motor coil; if Vf is close to Vd, it may indicate an open circuit in the motor coil. By comparing Vf with the preset normal range, the motor's condition can be determined.

[0048] II. The working principle of the motor drive circuit is as follows:

[0049] 1. Motor rotates forward:

[0050] Q1 is on, Q4 is on: At this time, the external DC power supply supplies power to the positive terminal of the motor through Q1, while the negative terminal of the motor is grounded through Q4, forming a closed loop, and the motor rotates in the forward direction. Q2 is off, Q3 is off: This ensures that no short circuit path is formed.

[0051] 2. Motor reverses:

[0052] When Q2 and Q3 are on, the external DC power supply provides power to the negative terminal of the motor through Q2, while the positive terminal of the motor is grounded through Q3, forming a closed loop, and the motor reverses direction. When Q1 and Q4 are off, it ensures that no short circuit path is formed.

[0053] 3. Motor stops:

[0054] All MOSFETs are off: Q1, Q2, Q3, and Q4 are all off, so no current flows through the motor, and it stops rotating.

[0055] III. The overall workflow is as follows:

[0056] 1. Pre-startup diagnostics:

[0057] Before starting the motor, the system first activates the motor diagnostic circuit to detect the motor's status through the steps described above.

[0058] If the diagnostic results show that the motor is normal, proceed to the next step; if the motor is abnormal, an alarm signal will be issued and the motor will be prevented from starting.

[0059] 2. Motor start-up:

[0060] Based on user requirements, select appropriate control signals to drive the MOSFETs in the H-bridge, so that the motor rotates in a predetermined direction.

[0061] It should also be noted that the terms used in this utility model, such as "front", "rear", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0062] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A novel H-bridge circuit, characterized in that: It includes a motor diagnostic circuit and a motor drive circuit. The motor diagnostic circuit includes three resistors that form a resistor divider network. The motor drive circuit includes two PMOS transistors and two NMOS transistors.

2. The novel H-bridge circuit according to claim 1, characterized in that: The motor diagnostic circuit includes: Resistor R1, the first end of which is connected to an external diagnostic power supply, and the second end of which is connected to the positive terminal of the motor; Resistor R2, the first end of which is connected to the negative terminal of the motor, and the second end of which is connected to the diagnostic feedback point; Resistor R3, the first end of which is connected to the second end of resistor R2, and the second end of resistor R3 is grounded.

3. The novel H-bridge circuit according to claim 1, characterized in that: The motor drive circuit includes: PMOS transistor Q1, the source S of which is connected to an external DC power supply, the gate G of which is connected to the forward rotation upper arm control signal, and the drain D of which is connected to the positive terminal of the motor; PMOS transistor Q2, the source S of which is connected to an external DC power supply, the gate G of which is connected to an inverted upper arm control signal, and the drain D of which is connected to the negative terminal of the motor; NMOS transistor Q3, the source S of which is grounded, the gate G of which is connected to the inverted lower arm control signal, and the drain D of which is connected to the positive terminal of the motor; NMOS transistor Q4, the source S of which is grounded, the gate G of which is connected to the forward rotation lower arm control signal, and the drain D of which is connected to the negative terminal of the motor.

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