Overcurrent protection circuit and massage chair

Abstract

The utility model relates to the technical field of over-current protection, and provides an over-current protection circuit and a massage armchair, an over-current protection mechanism is designed by a main controller and a motor driving chip U1 of the massage armchair, on one hand, based on the over-current protection mechanism of the motor driving chip U1, a signal is output to drive a signal control module to stop driving external equipment; on the other hand, the MCU carries out real-time monitoring through the sampling module, further controls the signal control module to disconnect the loop, and realizes dual overcurrent protection; and when the current exceeds a set value, the power supply is automatically cut off, so that potential safety hazards such as a fire hazard caused by overlarge current are avoided, the motor is prevented from being damaged due to overload, the motor can be effectively protected, the service life of the motor is prolonged, and the overall safety is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of overcurrent protection, in particular to an overcurrent protection circuit and a massage chair. Background Art

[0002] With the continuous development of the economy and the ever-accelerating pace of life, people are increasingly prioritizing their physical and mental health. Massage therapy for health care is a traditional practice in Chinese medicine, suitable for both young and old, and widely applicable. With the emergence of various massage devices with health-related functions, such as massage chairs, massage bathtubs, and massage foot basins, they are gaining popularity among consumers experiencing sub-health conditions due to their significant effectiveness in relieving stress and fatigue. The enormous demand and potential for development will undoubtedly drive the rapid development of various types of home massage devices, making them a new growth point for the health industry.

[0003] In a massage chair, external devices such as the walking motor are controlled by the motor driver chip U1. When the walking motor encounters a problem and remains in a non-turning state even when it reaches the upper or lower limit, the motor is in a stalled state, causing the current in some circuits of the walking motor to increase, resulting in a current overload phenomenon, which will damage the massage chair mechanism or affect the user's safety, posing a major safety hazard.

[0004] Existing protection solutions typically involve installing a circuit breaker or an additional protection chip to detect overcurrent, which is then fed back to the MCU, causing the motor driver chip U1 to stop operating to protect the circuit. This solution requires an additional protection chip for logic detection, resulting in high costs and hindering miniaturization. Utility Model Content

[0005] The utility model provides an overcurrent protection circuit and a massage chair, which solves the technical problems of high cost and large size of the existing overcurrent protection circuit of the massage chair.

[0006] In order to solve the above technical problems, the present utility model provides an overcurrent protection circuit, including a sampling module connected to the motor driver chip U1, at least one group of signal control modules, and an overcurrent detection module connected to the sampling module, the overcurrent detection module is connected to the feedback pin of the main controller, the control end of the main controller is connected to the input end of the signal control module; the output end of the signal control module is connected to an external device.

[0007] This basic solution uses the massage chair's own main controller and motor driver chip U1 to design an overcurrent protection mechanism. On the one hand, based on the overcurrent protection mechanism of the motor driver chip U1, the output signal drives the signal control module to stop driving the external device; on the other hand, the MCU performs real-time monitoring through the sampling module, and further controls the signal control module to disconnect the loop to achieve double overcurrent protection; and then monitors the current of the massage chair motor in real time. When the current exceeds the set value, the power supply is automatically cut off to avoid safety hazards such as fire caused by excessive current, and prevent the motor from being damaged due to overload. This can effectively protect the motor, extend its service life and improve overall safety.

[0008] In a further embodiment, the sampling module includes a resistor R1, a resistor R2 and a resistor R3; one end of the resistor R1 is connected to the output end of the motor driver chip U1, and the other end is grounded through the resistor R2, the resistor R3 is connected in parallel with the resistor R2, and the other end of the resistor R1 is also connected to the overcurrent detection module.

[0009] This solution directly connects the sampling module to the output end of the motor driver chip U1. When the motor driver chip U1 performs overload protection and outputs a high level, the sampling module is triggered to output the ADC sampling result to the overcurrent detection module for signal processing. It has a simple structure and low cost.

[0010] In a further embodiment, the overcurrent detection module includes a diode D1, a first switch tube Q1, a second switch tube Q2, and resistors R4 to R8;

[0011] The anode of the diode D1 is connected to the sampling module, and the cathode is connected to the control electrode of the first switch tube Q1; the first end of the first switch tube Q1 is connected to the power output end through the resistor R5, and the second end is grounded; the first end of the second switch tube Q2 is grounded through the resistor R7, the second end is connected to the power output end, and the control electrode is connected to the first end of the first switch tube Q1 through the resistor R6; one end of the resistor R8 is connected to the first end of the second switch tube Q2, and the other end is connected to the cathode of the diode D1; the first end of the second switch tube Q2 is also connected to the feedback pin of the main controller.

[0012] This solution uses a diode D1 to filter the collected signal. Only when the overcurrent threshold is reached will D1 be turned on, and then the first switch tube Q1 and the second switch tube Q2 are turned on in sequence, outputting a stable overcurrent sampling feedback signal to the main controller; wherein, a resistor R8 is connected between the first end of the second switch tube Q2 and the cathode of the diode D1. When it is confirmed that the overcurrent sampling feedback signal has been collected, the first switch tube Q1 is kept in the on state to achieve circuit self-locking. The self-locking can only be released after the power is restarted, thereby ensuring that the device can only work normally after the overcurrent is resolved, and the device has high safety.

[0013] In a further embodiment, a filtering module is further included, which includes a filtering capacitor C1 and a resistor R9; the positive electrode of the filtering capacitor C1 is connected to the negative electrode of the diode D1, and the positive electrode is grounded; the resistor R9 is connected in parallel with the filtering capacitor C1.

[0014] This solution sets up a filtering module, using filter capacitor C1 and resistor R9 to form an RC filtering mechanism, which can effectively reduce and remove noise in the signal and has good anti-interference performance.

[0015] In a further embodiment, the signal control module includes a third switch tube Q3, a resistor R10 and a resistor R11; the control electrode of the third switch tube Q3 is connected to the control end of the main controller through the resistor R11, the first end is connected to the external device through the resistor R10, and the second end is connected to the output end of the motor drive chip U1 and the sampling module.

[0016] In this solution, the negative electrode of the external device is connected to the third switch tube Q3. On the one hand, the motor driver chip U1 can output a high level to the second end of the third switch tube Q3, which can quickly cut off the power circuit of the external device; on the other hand, the main controller outputs a control signal to the control electrode of the third switch tube Q3, thereby achieving low power consumption of circuit disconnection.

[0017] In a further embodiment, a switch module is further included, wherein the input end of the switch module is connected to the power input end, and the output end serves as the power output end and is connected to the motor drive chip U1 and the overcurrent detection module.

[0018] This solution uses a combination of conventional switch modules and a main controller to achieve high-precision output voltage and current control. Combined with the overcurrent detection module, it can effectively prevent the power supply and load equipment from being damaged due to abnormal conditions, thereby improving the reliability and stability of the system.

[0019] In a further embodiment, the main controller comprises an MCU.

[0020] The utility model also provides a massage chair, comprising a chair body, and a travel motor and a main control circuit board installed inside the chair body, wherein the main control circuit board is provided with an overcurrent protection circuit as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a system framework diagram of an overcurrent protection circuit provided by an embodiment of the present utility model;

[0022] Figure 2 The embodiment of the present utility model provides Figure 1 The middle part of the hardware circuit diagram;

[0023] Figure 3 The embodiment of the present utility model provides Figure 1 Hardware circuit diagram of overcurrent detection module 3;

[0024] Figure 4 The embodiment of the present utility model provides Figure 1 Hardware circuit diagram of the middle switch module 6;

[0025] Among them: sampling module 1, signal control module 2, overcurrent detection module 3, main controller 4, filter module 5, switch module 6, external device 7. DETAILED DESCRIPTION

[0026] The following describes the implementation methods of the present invention in detail with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and are not to be construed as limiting the present invention. The accompanying drawings are provided for reference and illustration purposes only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0027] Example 1

[0028] The present invention provides an overcurrent protection circuit, such as Figures 1 to 4 As shown, in this embodiment, it includes a sampling module connected to the motor driver chip U1, at least one group of signal control modules, and an overcurrent detection module connected to the sampling module. The overcurrent detection module is connected to the feedback pin of the main controller, and the control end of the main controller is connected to the input end of the signal control module; the output end of the signal control module is connected to an external device.

[0029] In this embodiment, the sampling module includes a resistor R1, a resistor R2 and a resistor R3; one end of the resistor R1 is connected to the output end of the motor driver chip U1, and the other end is grounded through the resistor R2. The resistor R3 is connected in parallel with the resistor R2, and the other end of the resistor R1 is also connected to the overcurrent detection module.

[0030] In this embodiment, a sampling module is directly connected to the output end of the motor driver chip U1. When the motor driver chip U1 performs overload protection and outputs a high level, the sampling module is triggered to output the ADC sampling result to the overcurrent detection module for signal processing. The structure is simple and the cost is low.

[0031] In this embodiment, the overcurrent detection module includes a diode D1, a first switch tube Q1, a second switch tube Q2, and resistors R4 to R8;

[0032] The anode of the diode D1 is connected with the sampling module, and the cathode is connected with the control electrode of the first switch tube Q1; the first end of the first switch tube Q1 is connected with the power output end through the resistor R5, and the second end is grounded; the first end of the second switch tube Q2 is grounded through the resistor R7, and the second end is connected with the power output end; the control electrode is connected with the first end of the first switch tube Q1 through the resistor R6; one end of the resistor R8 is connected with the first end of the second switch tube Q2, and the other end is connected with the cathode of the diode D1; the first end of the second switch tube Q2 is also connected with the feedback pin of the main controller.

[0033] Among them, the first switch tube Q1 and the second switch tube Q2 are NPN triodes or PNP triodes, which can be customized according to actual needs.

[0034] In this embodiment, the diode D1 is used to filter the collected signal. Only when the overcurrent threshold is reached, D1 will be turned on, and then the first switch tube Q1 and the second switch tube Q2 are turned on in turn, and a stable overcurrent sampling feedback signal is output to the main controller; among them, the resistor R8 is connected between the first end of the second switch tube Q2 and the cathode of the diode D1, and when the overcurrent sampling feedback signal is confirmed to be collected, the first switch tube Q1 is kept in the on state to realize circuit self-locking. Only after restarting the power supply can the self-locking be released, thereby ensuring that the equipment can work normally only after the overcurrent is solved, and the equipment safety is high.

[0035] In this embodiment, the embodiment also includes a filtering module, which includes a filtering capacitor C1 and a resistor R9; the anode of the filtering capacitor C1 is connected with the cathode of the diode D1, and the anode is grounded; the resistor R9 is connected with the filtering capacitor C1 in parallel.

[0036] Among them, the filtering capacitor C1 is an energy storage capacitor.

[0037] In this embodiment, the filtering module is set, and the RC filtering mechanism composed of the filtering capacitor C1 and the resistor R9 can effectively reduce and remove the noise in the signal, and has good anti-interference performance.

[0038] In this embodiment, the signal control module includes a third switch tube Q3, a resistor R10 and a resistor R11; the control electrode of the third switch tube Q3 is connected with the control end of the main controller through the resistor R11, the first end is connected with the external device through the resistor R10, and the second end is connected with the output end of the motor drive chip U1 and the sampling module.

[0039] Among them, the third switch tube Q3 is an NPN triode or a PNP triode, which can be customized according to actual needs.

[0040] In this embodiment, the negative electrode of the external device is connected to the third switch tube Q3. On the one hand, a high level can be output to the second end of the third switch tube Q3 through the motor driver chip U1, which can quickly cut off the power circuit of the external device. On the other hand, the main controller outputs a control signal to the control electrode of the third switch tube Q3, thereby achieving low power consumption of circuit disconnection.

[0041] In this embodiment, a switch module is further included. The input end of the switch module is connected to the power input end, and the output end serves as a power output end and is connected to the motor drive chip U1 and the overcurrent detection module.

[0042] The switch module uses a combination of MOS tubes and switch tubes, see Figure 4 Assume that the fourth switch tube Q4 is an N-channel MOS tube and the fifth switch tube Q5 is an NPN transistor. The source of the fourth switch tube Q4 is connected to the power input terminal, the drain is connected to the power output terminal, and the gate is connected to the emitter of the fifth switch tube Q5 via the resistor R13. The two ends of the resistor R12 are connected to the source and gate of the fourth switch tube Q4, respectively.

[0043] The emitter of the fifth switch tube Q5 is grounded, and the base is connected to the main controller via the resistor R14; both ends of the resistor R15 are connected to the base and emitter of the fifth switch tube Q5.

[0044] This embodiment uses a combination of a conventional switch module and a main controller to achieve high-precision output voltage and current control. In conjunction with the overcurrent detection module, it can effectively prevent the power supply and load equipment from being damaged due to abnormal conditions, thereby improving the reliability and stability of the system.

[0045] In this embodiment, the main controller includes an MCU.

[0046] In this embodiment, the motor driver chip U1 includes but is not limited to the TMI8360 driver chip.

[0047] Taking the main controller as MCU, the first switch tube Q1 and the third switch tube Q3 as NPN transistors, and the second switch tube Q2 as PNP transistor as an example, the overcurrent protection principle is as follows:

[0048] The motor driver chip U1 has a built-in H-bridge. The inputs of ports 1 and 2 can tell whether the H-bridge is turned on or not. When there is overcurrent, the input is grounded (pin 8 is grounded through pin 3). At this time, the output end outputs a high level.

[0049] The emitter of the third switch tube Q3 is at a high level, the third switch tube Q3 is turned off, and the external device is disconnected.

[0050] At this time, the ADC pin outputs the sampling signal to the diode D1 under the action of the voltage divider circuit.

[0051] If the current exceeds the preset value, the voltage across the sampling resistors "R2+R3" turns on the diode D1. The filter formed by capacitor C1 and resistor 9 filters out interference and delays charging. The current then passes through resistor R4 and enters the base of the first switching tube Q1, saturating and turning on the first switching tube Q1. The collector potential of the first switching tube Q1 drops, which in turn causes the base potential of the second switching tube Q2 to drop through resistor R6. The second switching tube Q2 turns on, causing the collector potential of the second switching tube Q2 to rise, outputting a high potential. At the same time, the high collector potential of the second switching tube Q2 is fed back to resistor R2 through resistor R8, maintaining a high potential at the base of the first switching tube Q1. The first switching tube Q1 remains on, achieving circuit self-locking.

[0052] Then, the MCU detects an overcurrent signal through the FB pin and outputs a low level through the signal-1 pin, turning off the third switch tube Q3.

[0053] Finally, the MCU outputs a switching signal to turn off the fourth switch tube Q4 and the fifth switch tube Q5, thereby completely shutting off the power supply.

[0054] Example 2

[0055] An embodiment of the present invention also provides a massage chair, comprising a chair body, and a travel motor and a main control circuit board installed inside the chair body, wherein the main control circuit board is provided with an overcurrent protection circuit as described in the above embodiment 1, wherein the travel motor is connected to the motor drive chip U1.

[0056] The embodiment of the present utility model designs an overcurrent protection mechanism based on the main controller and motor driver chip U1 of the massage chair itself. On the one hand, based on the overcurrent protection mechanism of the motor driver chip U1, the output signal drives the signal control module to stop driving the external device; on the other hand, the MCU performs real-time monitoring through the sampling module, and further controls the signal control module to disconnect the loop to achieve double overcurrent protection; and then monitors the current of the massage chair motor in real time. When the current exceeds the set value, the power supply is automatically cut off to avoid safety hazards such as fire caused by excessive current, and prevent the motor from being damaged due to overload. This can effectively protect the motor, extend its service life and improve overall safety.

[0057] The above embodiments are preferred implementation methods of the present invention, but the implementation methods of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. An overcurrent protection circuit, characterized in that: It includes a sampling module connected to the motor driver chip U1, at least one group of signal control modules, and an overcurrent detection module connected to the sampling module. The overcurrent detection module is connected to the feedback pin of the main controller, and the control end of the main controller is connected to the input end of the signal control module; the output end of the signal control module is connected to an external device.

2. The overcurrent protection circuit according to claim 1, wherein: The sampling module includes a resistor R1, a resistor R2 and a resistor R3; one end of the resistor R1 is connected to the output end of the motor driver chip U1, and the other end is grounded through the resistor R2. The resistor R3 is connected in parallel with the resistor R2, and the other end of the resistor R1 is also connected to the overcurrent detection module.

3. The overcurrent protection circuit according to claim 2, wherein: The overcurrent detection module includes a diode D1, a first switch tube Q1, a second switch tube Q2, and resistors R4 to R8; The anode of the diode D1 is connected to the sampling module, and the cathode is connected to the control electrode of the first switch tube Q1; the first end of the first switch tube Q1 is connected to the power output end through the resistor R5, and the second end is grounded; the first end of the second switch tube Q2 is grounded through the resistor R7, the second end is connected to the power output end, and the control electrode is connected to the first end of the first switch tube Q1 through the resistor R6; one end of the resistor R8 is connected to the first end of the second switch tube Q2, and the other end is connected to the cathode of the diode D1; the first end of the second switch tube Q2 is also connected to the feedback pin of the main controller.

4. The overcurrent protection circuit according to claim 3, wherein: It also includes a filtering module, which includes a filtering capacitor C1 and a resistor R9; the positive electrode of the filtering capacitor C1 is connected to the negative electrode of the diode D1, and the positive electrode is grounded; the resistor R9 is connected in parallel with the filtering capacitor C1.

5. The overcurrent protection circuit according to claim 4, wherein: The signal control module includes a third switch tube Q3, a resistor R10 and a resistor R11; the control electrode of the third switch tube Q3 is connected to the control end of the main controller through the resistor R11, the first end is connected to the external device through the resistor R10, and the second end is connected to the output end of the motor drive chip U1 and the sampling module.

6. The overcurrent protection circuit according to claim 1, wherein: It also includes a switch module, the input end of the switch module is connected to the power input end, and the output end is connected to the motor drive chip U1 and the overcurrent detection module as a power output end.

7. The overcurrent protection circuit according to claim 1, wherein: The main controller includes an MCU.

8. A massage chair, characterized in that: The invention comprises a chair body, a travel motor and a main control circuit board installed inside the chair body, wherein the main control circuit board is provided with an overcurrent protection circuit according to any one of claims 1 to 7.

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