Variable frequency drive circuit for treadmill

Abstract

The utility model provides a variable frequency drive circuit for a treadmill, and relates to the field of drive circuits, the variable frequency drive circuit for the treadmill comprises an MCU, a control module, a drive circuit, a power circuit, an induction motor, a drive power supply and a current sampling circuit, the control module is electrically connected with the MCU, and the drive circuit is electrically connected with the control module. The MCU is electrically connected with the input end of the driving circuit, the output end of the driving circuit is connected with the input end of the power circuit, the output end of the power circuit is connected with the induction motor, the driving power supply is electrically connected with the power circuit, the input end of the current sampling circuit is electrically connected with the induction motor, and the output end of the current sampling circuit is electrically connected with the induction motor. The output end of the current sampling circuit is electrically connected with the MCU, the driving circuit is adopted for driving, the driving circuit is simple, frequency conversion can be achieved through cooperation of the driving circuit and the power circuit, the design is simple, and the manufacturing cost is low.

Description

Technical Field

[0001] The present application relates to the field of drive circuits, and in particular, to a variable frequency drive circuit for a treadmill. Background Art

[0002] Variable frequency drive is currently used in the air conditioning field, but is less used on treadmills. In addition, the current air conditioning variable frequency drive circuit is complex and has high manufacturing costs, which is not suitable for treadmills. Therefore, the current variable frequency drive circuit needs to be improved. Summary of the Invention

[0003] The purpose of the embodiments of the present application is to provide a variable frequency drive circuit for a treadmill, which can solve the complex technical problems of the variable frequency circuit.

[0004] An embodiment of the present application provides a variable frequency drive circuit for a treadmill, including an MCU, a control module, a drive circuit, a power circuit, an induction motor, a drive power supply and a current sampling circuit. The control module is electrically connected to the MCU, the MCU is electrically connected to the input end of the drive circuit, the output end of the drive circuit is connected to the input end of the power circuit, the output end of the power circuit is connected to the induction motor, the drive power supply is electrically connected to the power circuit, the input end of the current sampling circuit is electrically connected to the induction motor, and the output end of the current sampling circuit is electrically connected to the MCU.

[0005] Preferably, the model of the MCU is TMS320LF2407.

[0006] Preferably, the driving circuit includes a photocoupler IC1, a photocoupler IC2, a first bridge arm circuit, and a second bridge arm circuit. The input end of the photocoupler IC1 and the input end of the photocoupler IC2 are both connected to the MCU, the output end of the photocoupler IC1 is connected to the input end of the first bridge arm circuit, the output end of the first bridge arm circuit is connected to the input end of the power circuit, the output end of the photocoupler IC2 is connected to the input end of the second bridge arm circuit, and the output end of the second bridge arm circuit is connected to the input end of the power circuit.

[0007] Preferably, the power circuit includes a resistor R5, a resistor R6, a transistor V1, a resistor R11, a resistor R12, and a transistor V4.

[0008] Preferably, the induction motor is a three-phase induction motor.

[0009] Preferably, a voltage stabilizing and step-down circuit is provided between the driving power supply and the MCU.

[0010] Preferably, the output voltage of the voltage-stabilizing and step-down circuit is 5V and 15V.

[0011] Beneficial effects of the utility model:

[0012] The utility model provides a variable frequency drive circuit for a treadmill, comprising an MCU, a control module, a drive circuit, a power circuit, an induction motor, a drive power supply and a current sampling circuit. The control module is electrically connected to the MCU, the MCU is electrically connected to the input end of the drive circuit, the output end of the drive circuit is connected to the input end of the power circuit, the output end of the power circuit is connected to the induction motor, the drive power supply is electrically connected to the power circuit, the input end of the current sampling circuit is electrically connected to the induction motor, and the output end of the current sampling circuit is electrically connected to the MCU. The utility model adopts a drive circuit for driving, and the drive circuit of the utility model is simple, and frequency conversion can be achieved by cooperating with the power circuit. The design is simple and the manufacturing cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 This is a connection diagram of the drive circuit and power circuit of the utility model. DETAILED DESCRIPTION

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0016] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0017] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0018] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0019] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0020] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0021] like Figure 1 As shown, a variable frequency drive circuit for a treadmill includes an MCU, a control module, a drive circuit, a power circuit, an induction motor, a drive power supply and a current sampling circuit. The control module is electrically connected to the MCU, the MCU is electrically connected to the input end of the drive circuit, the output end of the drive circuit is connected to the input end of the power circuit, the output end of the power circuit is connected to the induction motor, the drive power supply is electrically connected to the power circuit, the input end of the current sampling circuit is electrically connected to the induction motor, and the output end of the current adopting circuit is electrically connected to the MCU. The utility model adopts a drive circuit for driving, and the drive circuit of the utility model is simple. Frequency conversion can be achieved by cooperating with the power circuit. The design is simple and the manufacturing cost is low.

[0022] In this embodiment, the model of the MCU is TMS320LF2407.

[0023] like Figure 1 As shown, in this embodiment, the driving circuit includes a photocoupler IC1, a photocoupler IC2, a first bridge arm circuit, and a second bridge arm circuit. The input end of the photocoupler IC1 and the input end of the photocoupler IC2 are both connected to the MCU, the output end of the photocoupler IC1 is connected to the input end of the first bridge arm circuit, the output end of the first bridge arm circuit is connected to the input end of the power circuit, the output end of the photocoupler IC2 is connected to the input end of the second bridge arm circuit, and the output end of the second bridge arm circuit is connected to the input end of the power circuit.

[0024] like Figure 1 As shown, in this embodiment, the power circuit includes a resistor R5, a resistor R6, a transistor V1, a resistor R11, a resistor R12, and a transistor V4.

[0025] Specifically, when the upper tube V1 is turned off and the lower tube V4 is turned on, the potential at point N is +15V, point M is +15V, and the voltage of capacitor C5 is +15V; when the upper tube V1 is turned on and the lower tube V4 is turned off, the potential at point M is Vdc, and the potential at point N is (Vdc+15)V because the voltage of the bootstrap capacitor C5 cannot change transiently. The bootstrap diode D1 is then turned off due to the reverse voltage, thereby protecting the +15V power supply. The bootstrap capacitor C5 needs to have a large capacitance value, and a bipolar modulation method is used. Under the condition of a carrier frequency of 20kHz, the measured voltage fluctuation of the bootstrap capacitor does not exceed 100mV, thereby ensuring the reliable operation of the upper bridge power switch tube. The utility model uses an optocoupler for electrical isolation, thereby improving the system's anti-interference ability. Long-term operation results show that the drive circuit is simple and practical, and can ensure that the power device is reliably turned on and off.

[0026] Specifically, the induction motor is a three-phase induction motor.

[0027] In this embodiment, a voltage stabilizing and bucking circuit is provided between the driving power supply and the MCU, and the output voltage of the voltage stabilizing and bucking circuit is 5V and 15V.

[0028] The current step-down voltage stabilization circuit is an existing technology and will not be repeated here.

[0029] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A variable frequency drive circuit for a treadmill, characterized in that: The invention comprises an MCU, a control module, a drive circuit, a power circuit, an induction motor, a drive power supply and a current sampling circuit. The control module is electrically connected to the MCU, the MCU is electrically connected to the input end of the drive circuit, the output end of the drive circuit is connected to the input end of the power circuit, the output end of the power circuit is connected to the induction motor, the drive power supply is electrically connected to the power circuit, the input end of the current sampling circuit is electrically connected to the induction motor, and the output end of the current sampling circuit is electrically connected to the MCU.

2. The variable frequency drive circuit for a treadmill according to claim 1, characterized in that: The model of the MCU is TMS320LF2407.

3. The variable frequency drive circuit for a treadmill according to claim 1, characterized in that: The driving circuit includes a photocoupler IC1, a photocoupler IC2, a first bridge arm circuit, and a second bridge arm circuit. The input end of the photocoupler IC1 and the input end of the photocoupler IC2 are both connected to the MCU, the output end of the photocoupler IC1 is connected to the input end of the first bridge arm circuit, the output end of the first bridge arm circuit is connected to the input end of the power circuit, the output end of the photocoupler IC2 is connected to the input end of the second bridge arm circuit, and the output end of the second bridge arm circuit is connected to the input end of the power circuit.

4. The variable frequency drive circuit for a treadmill according to claim 1, characterized in that: The power circuit includes a resistor R5, a resistor R6, a transistor V1, a resistor R11, a resistor R12, and a transistor V4.

5. The variable frequency drive circuit for a treadmill according to claim 1, characterized in that: The induction motor is a three-phase induction motor.

6. The variable frequency drive circuit for a treadmill according to claim 1, characterized in that: A voltage stabilizing and step-down circuit is provided between the driving power supply and the MCU.

7. The variable frequency drive circuit for a treadmill according to claim 6, characterized in that: The output voltage of the voltage-stabilizing and step-down circuit is 5V and 15V.

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