A control circuit for a tire balancing machine

Abstract

The utility model relates to a control circuit for tire balancing machine, including a plurality of capacitive touch sensor for producing finger approach signal, touch detection circuit is connected to each capacitive touch sensor's front end respectively each input, for converting the finger approach signal that capacitive touch sensor produced is the stable level signal, signal conversion circuit is connected to each output of touch detection circuit through isolation circuit respectively each input, its each output is connected to the different IO pin of main control circuit respectively, for converting the level signal is the matrix key signal, main control circuit is used for controlling the action of tire balancing machine or tire changing machine according to the matrix key signal received, power supply circuit is used for the power supply of touch detection circuit and isolation circuit. Adopt the circuit of the utility model can effectively improve tire balancing machine or tire changing machine's control circuit's life, and its work reliability.

Description

Technical Field

[0001] This utility model generally relates to the field of control circuit technology. More specifically, this utility model relates to... A type of Control circuit of tire balancer . Background Technology

[0002] Tire balancers and tire changers are commonly used in car repair shops, tire shops, and 4S dealerships. A tire balancer is a specialized piece of equipment used to detect and correct imbalances in car tires and wheel assemblies. The main functions of a tire balancer are: to detect the dynamic balance of the tires during rotation, to locate the imbalance, and to guide the addition of counterweights to eliminate the imbalance.

[0003] In the prior art, the control circuit for tire balancers typically includes mechanical buttons and a main control circuit. The main control circuit receives data connected to the mechanical buttons and controls the actuators connected to the tire balancer or tire changer. By pressing the mechanical buttons, signal commands are sent to the main control circuit, which then controls the movement of the tire balancer based on the received signal commands.

[0004] When using mechanical buttons to control the tire balancing machine, the operator's fingers must directly or indirectly contact the buttons, which can easily damage the control panel, affecting its overall appearance and shortening the lifespan of the control device. For example, operators are often repairing vehicles, wearing gloves, or with dirty hands, or even holding tools. In such situations, they might directly use tools on the buttons, remove their gloves, or get their fingers dirty or scratch the surface. In real-world environments, contact buttons are easily damaged by uncontrollable external forces. Furthermore, mechanical contact is prone to contact oxidation and short circuits, further reducing the reliability of the control device. Utility Model Content

[0005] To address the technical problems of short lifespan and poor reliability of control circuits in existing tire balancing machines, this utility model provides solutions in the following aspects.

[0006] In a first aspect, the present invention provides a control circuit for a tire balancing machine, comprising:

[0007] Multiple capacitive touch sensors are used to generate finger proximity signals;

[0008] The touch detection circuit has its input terminals connected to the front end of each capacitive touch sensor, which is used to convert the finger proximity signal generated by the capacitive touch sensor into a stable level signal.

[0009] The signal conversion circuit has its input terminals connected to the output terminals of the touch detection circuit via isolation circuits, and its output terminals connected to different I / O pins of the main control circuit, for converting the level signal into matrix key signals. The signal conversion circuit includes a tri-state buffer, the output enable pin of the tri-state buffer is connected to the output terminal of the touch detection circuit via an isolation circuit, and the output pin of the tri-state buffer is connected to the I / O pin of the main control circuit via a Zener diode. The anode of the Zener diode is connected to the I / O pin of the main control circuit, and the cathode is connected to the output pin of the tri-state buffer.

[0010] The main control circuit is used to control the movement of the tire balancer based on the received matrix key signals.

[0011] A power supply circuit is used to supply power to the touch detection circuit and the isolation circuit.

[0012] Preferably, the input pin of the tri-state buffer is connected to the first power supply voltage via a pull-up resistor.

[0013] Preferably, the power supply circuit includes a DC-DC converter and a linear regulator, wherein the input voltage pin of the DC-DC converter is connected to a first supply voltage through a first inductor, and the two ends of the first inductor are grounded through a first filter capacitor and a second filter capacitor, respectively. The output voltage pin of the DC-DC converter is connected to the input voltage pin of the linear regulator, and the output voltage pin of the linear regulator is the output terminal of the power supply circuit.

[0014] Preferably, the output voltage pin of the DC-DC converter is grounded through a third filter capacitor, and the output voltage pin of the linear regulator is grounded through a fourth filter capacitor.

[0015] Preferably, the touch detection circuit is a capacitive touch controller. The touch key input pin of the capacitive touch controller is connected to the front end of the capacitive touch sensor. Its touch detection output signal pin is connected to the output enable terminal of the tri-state buffer through an isolation circuit. Its power supply positive pin is connected to the output voltage pin of the linear regulator. Its power supply negative pin is grounded. Its power supply positive pin is connected to its power supply negative pin through a filter capacitor.

[0016] Preferably, the isolation circuit adopts a dual-channel digital isolator. The logic input pin of the primary side of the dual-channel digital isolator is connected to the touch detection output signal pin of the capacitive touch controller, the logic output pin of the secondary side of the dual-channel digital isolator is connected to the output enable terminal of the tri-state buffer, and the power supply pin of the dual-channel digital isolator is connected to the output voltage pin of the linear regulator.

[0017] Preferably, the power supply pin of the dual-channel digital isolator is grounded through the sixth filter capacitor.

[0018] Preferably, the logic output pin of the secondary side of the dual-channel digital isolator is connected to the output enable terminal of the tri-state buffer via a first pin connector.

[0019] Preferably, the front end of the capacitive touch sensor is grounded by adjusting the capacitor.

[0020] Preferably, the anode of the Zener diode is connected to the I / O pin of the main control circuit via a second pin connector.

[0021] The technical advantages of this invention are as follows: By incorporating a touch detection circuit into the touch button circuit, this invention converts the weak sensing signal collected by the capacitive touch sensor into a stable level signal, ensuring that the main control circuit effectively acquires the touch signal. Since the level signal generated by the touch detection circuit is susceptible to interference, an isolation circuit is installed between the signal conversion circuit and the touch detection circuit to increase the anti-interference performance of the entire control circuit, making the button circuit more stable and reliable. Because directly receiving a high-level signal from the main control circuit's I / O may cause malfunctions, a Zener diode is used. Even if the output of the tri-state buffer is high, the Zener diode clamps the signal received by the main control circuit's I / O, keeping it within an acceptable range, thus further improving the reliability of the control circuit. The control circuit using this invention can effectively improve the lifespan and operational reliability of the control circuit of a tire balancer or tire changer. Attached Figure Description

[0022] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the present invention are shown by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0023] Figure 1 This is a schematic diagram of the control circuit structure for a tire balancing machine according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the signal conversion circuit according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the power supply circuit according to an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of a capacitive touch controller according to an embodiment of this utility model;

[0027] Figure 5 This is a schematic diagram of the isolation circuit according to an embodiment of the present invention;

[0028] Figure 6 This is a capacitive touch sensor, which is an embodiment of the present invention. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0030] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0031] Example of a control circuit for a tire balancing machine:

[0032] like Figure 1 As shown, the control circuit for a tire balancing machine of this invention includes: multiple capacitive touch sensors for generating finger proximity signals; a touch detection circuit, whose input terminals are respectively connected to the front end of each capacitive touch sensor, for converting the finger proximity signals generated by the capacitive touch sensors into stable level signals; a signal conversion circuit, whose input terminals are respectively connected to the output terminals of the touch detection circuit through isolation circuits, and whose output terminals are respectively connected to different I / O pins of the main control circuit, for converting the level signals into matrix key signals; the signal conversion circuit includes a tri-state buffer, the output enable terminal of the tri-state buffer is connected to the output terminal of the touch detection circuit through an isolation circuit, the output terminal of the tri-state buffer is connected to the I / O pin of the main control circuit through a Zener diode, the anode of the Zener diode is connected to the I / O pin of the main control circuit, and the cathode is connected to the output terminal of the tri-state buffer; a main control circuit for controlling the operation of the tire balancing machine according to the received matrix key signals; and a power supply circuit for supplying power to the touch detection circuit and the isolation circuit.

[0033] In this embodiment, a total of seven capacitive touch sensors are provided: a first capacitive touch sensor TK1, a second capacitive touch sensor TK2, a third capacitive touch sensor TK3, a fourth capacitive touch sensor TK4, a fifth capacitive touch sensor TK5, a sixth capacitive touch sensor TK6, and a seventh capacitive touch sensor TK7; each capacitive touch sensor corresponds to a different action command. In other embodiments, the number of capacitive touch sensors can also be other suitable numbers.

[0034] like Figure 2As shown, the signal conversion circuit in this embodiment has two tri-state buffers, namely the first tri-state buffer U1 and the second tri-state buffer U2. The first output enable pin 10E# and the power supply pin VCC of the first tri-state buffer U1 are both connected to the first power supply voltage VCC. The second output enable pin 20E#, the third output enable pin 30E# and the fourth output enable pin 40E# are all connected to the output terminal of the touch detection circuit through an isolation circuit. The second output pin 2Y, the third output pin 3Y and the fourth output pin 4Y are respectively connected to the IO pin of the main control circuit through a Zener diode (not shown in the figure). The first output enable pin 10E#, the second output enable pin 20E#, the third output enable pin 30E#, and the fourth output enable pin 40E# of the second tri-state buffer U2 are all connected to the output terminal of the touch detection circuit through an isolation circuit. Its first output pin 1Y, the second output pin 2Y, the third output pin 3Y, and the fourth output pin 4Y are connected to the IO pin of the main control circuit through Zener diodes (not shown in the figure).

[0035] In this embodiment, the tri-state buffer is a high-performance CMOS four-way tri-state buffer with model number 74HC123.

[0036] The working principle of the control circuit for the tire balancing machine in this embodiment is as follows:

[0037] Different capacitive touch sensors correspond to different control actions. When a user touches the front of a capacitive touch sensor with their finger, the capacitive touch sensor generates a weak finger proximity signal. The touch detection circuit converts the weak finger proximity signal into a stable level signal and transmits it to the enable terminal of the tri-state buffer through an isolation circuit. When the enable terminal of the tri-state buffer receives the level signal, its output terminal will output a low level signal and transmit it to the corresponding IO pin of the main control circuit. After the main control circuit detects that the level of one of its IO pins has become low, it will control the tire balancer or tire changer to perform the corresponding action.

[0038] By incorporating a touch detection circuit into the control circuit to convert the weak sensing signal acquired by the capacitive touch sensor into a stable level signal, the main control circuit can effectively acquire the touch signal. Since the level signal generated by the touch detection circuit is susceptible to interference, an isolation circuit is installed between the signal conversion circuit and the touch detection circuit to increase the anti-interference performance of the entire control circuit, making the button circuit more stable and reliable. Because directly receiving high-level signals at the main control circuit's I / O pins may cause malfunctions, a Zener diode is used. Even if the output of the tri-state buffer is high, the Zener diode's clamping effect ensures that the signal received by the main control circuit's I / O pins remains within an acceptable range, further improving the reliability of the control circuit.

[0039] To prevent the input pin of the tri-state buffer from being left floating, which could lead to unstable output of the buffer, in one embodiment, the input pin of the tri-state buffer is connected to a first supply voltage via a pull-up resistor.

[0040] Without pull-up pins on the input pins of a tri-state buffer, if the input pins are not connected or the I / O is not configured, they may float, causing unstable buffer output. Pull-up pins ensure that the input is high by default when there is no input driver.

[0041] like Figure 3 As shown, in one embodiment, the power supply circuit includes a DC-DC converter U4 and a linear regulator U8. The input voltage pin +Vin of the DC-DC converter is connected to the first supply voltage VCC through a first inductor L3. The two ends of the first inductor are grounded through a first filter capacitor C14 and a second filter capacitor C15, respectively. The output voltage pin +Vout of the DC-DC converter is connected to the input voltage pin VSS of the linear regulator. The output voltage pin VOUT of the linear regulator is the output terminal of the power supply circuit, and the voltage output by the linear regulator is the second supply voltage VCC1.

[0042] The DC-DC converter U4 can be a DC-DC converter with model number B0505S-1WR3.

[0043] To make the output voltage of the DC-DC converter and the output voltage of the linear regulator more stable, in one embodiment, the output voltage pin of the DC-DC converter is grounded through a third filter capacitor C16, and the output voltage pin of the linear regulator is grounded through a fourth filter capacitor C18.

[0044] In one embodiment, the touch detection circuit is a capacitive touch controller. The touch key input pin of the capacitive touch controller is connected to the front end of the capacitive touch sensor. Its touch detection output signal pin is connected to the output enable terminal of the tri-state buffer through an isolation circuit. Its power supply positive pin is connected to the output voltage pin of the linear regulator. Its power supply negative pin is grounded. Its power supply positive pin is connected to its power supply negative pin through a filter capacitor.

[0045] In this embodiment, as Figure 4As shown, since there are 7 capacitive touch sensors, two capacitive touch controllers are set up, namely the first capacitive touch controller U11 and the second capacitive touch controller U10. The first touch key input pin KEY1 of the first capacitive touch controller U11 is connected to the front end of the fourth capacitive touch sensor TK4, its second touch key input pin KEY2 is connected to the front end of the fifth capacitive touch sensor TK5, its third touch key input pin KEY3 is connected to the front end of the sixth capacitive touch sensor TK6, and its fourth touch key input pin KEY4 is connected to the front end of the seventh capacitive touch sensor TK7. Its positive power supply pin VDD is connected to the output voltage pin VOUT of the linear regulator, its negative power supply pin VSS is grounded, and its positive power supply pin VDD is connected to its negative power supply pin VSS through the filter capacitor C10.

[0046] The first touch key input pin KEY1 of the second capacitive touch controller U10 is connected to the front end of the first capacitive touch sensor TK1, its second touch key input pin KEY2 is connected to the front end of the third capacitive touch sensor TK3, its fourth touch key input pin KEY4 is connected to the front end of the second capacitive touch sensor TK2, its positive power supply pin VDD is connected to the output voltage pin VOUT of the linear regulator, its negative power supply pin VSS is grounded, and its positive power supply pin VDD is connected to its negative power supply pin VSS through a filter capacitor C11.

[0047] The capacitive touch sensor model number is BS814C-1-10MSOP.

[0048] In one embodiment, the isolation circuit employs a dual-channel digital isolator. The logic input pins on the primary side of the dual-channel digital isolator are connected to the touch detection output signal pins of the capacitive touch controller, the logic output pins on the secondary side of the dual-channel digital isolator are connected to the output enable pins of the tri-state buffer, and the power supply pins of the dual-channel digital isolator are connected to the output voltage pins of the linear regulator.

[0049] like Figure 5 As shown, in this embodiment, a total of four dual-channel digital isolators are provided, namely the first dual-channel digital isolator U3, the second dual-channel digital isolator U5, the third dual-channel digital isolator U6, and the fourth dual-channel digital isolator U7; wherein the second logic input pin VIB of the primary side of the first dual-channel digital isolator U3 is connected to the first touch detection output pin Kout1 of the second capacitive touch controller U10, and the second logic output pin VOB of its secondary side is connected to the fourth output enable pin 40E# of the first tri-state buffer U1.

[0050] The first logic input pin VIA of the primary side of the second dual-channel digital isolator U5 is connected to the second touch detection output pin Kout2 of the second capacitive touch controller U10, and the second logic input pin VIB of the primary side of the second dual-channel digital isolator U5 is connected to the fourth touch detection output pin Kout4 of the second capacitive touch controller U10; the first logic output pin VOA of its secondary side is connected to the second output enable pin 20E# of the first tri-state buffer U1, and the second logic output pin VOB of its secondary side is connected to the third output enable pin 30E# of the first tri-state buffer U1.

[0051] The first logic input pin VIA of the primary side of the third dual-channel digital isolator U6 is connected to the first touch detection output pin Kout1 of the first capacitive touch controller U11, and the second logic input pin VIB of the primary side is connected to the second touch detection output pin Kout2 of the first capacitive touch controller U11; the first logic output pin VOA of its secondary side is connected to the fourth output enable pin 40E# of the second tri-state buffer U2, and the second logic output pin VOB of its secondary side is connected to the third output enable pin 30E# of the second tri-state buffer U2.

[0052] The first logic input pin VIA of the primary side of the fourth dual-channel digital isolator U7 is connected to the third touch detection output pin Kout3 of the first capacitive touch controller U11, and the second logic input pin VIB of the primary side is connected to the fourth touch detection output pin Kout4 of the first capacitive touch controller U11; the first logic output pin VOA of its secondary side is connected to the first output enable pin 10E# of the second tri-state buffer U2, and the second logic output pin VOB of its secondary side is connected to the second output enable pin 20E# of the second tri-state buffer U2.

[0053] The primary power supply terminals of the first dual-channel digital isolator U3, the second dual-channel digital isolator U5, the third dual-channel digital isolator U6, and the fourth dual-channel digital isolator U7 are all connected to the output voltage pin VOUT of the linear regulator, and the secondary power supply terminals are all connected to the first supply voltage VCC.

[0054] The dual-channel digital isolator can be the π120U31 model.

[0055] To make the operation of the dual-channel digital isolator more stable, in one embodiment, the power supply pin of the dual-channel digital isolator is grounded through a filter capacitor.

[0056] To facilitate the connection and disconnection of the isolation circuit and the signal conversion circuit, in one embodiment, the logic output pins of each dual-channel digital isolator secondary side are connected to the output enable terminal of the tri-state buffer via a first pin connector.

[0057] To adjust the sensing sensitivity of a capacitive touch sensor, in one embodiment, the front end of the capacitive touch sensor is grounded by adjusting a capacitor. For example... Figure 6 As shown, the front ends of the first capacitive touch sensor TK1, the second capacitive touch sensor TK2, the third capacitive touch sensor TK3, the fourth capacitive touch sensor TK4, the fifth capacitive touch sensor TK5, the sixth capacitive touch sensor TK6, and the seventh capacitive touch sensor TK7 are grounded through the first adjusting capacitor C20, the second adjusting capacitor C21, the third adjusting capacitor C22, the fourth adjusting capacitor C25, the fifth adjusting capacitor C26, the sixth adjusting capacitor C27, and the eighth adjusting capacitor C23, respectively.

[0058] To facilitate the connection between the signal conversion circuit and the main control circuit, and to facilitate the disconnection between the signal conversion circuit and the main control circuit, the anode of the Zener diode is connected to the IO pin of the main control circuit through a second pin connector.

[0059] Furthermore, the terms "first" or "second," etc., used in this specification to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as indicating, explicitly or implicitly, relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0060] While this specification has shown and described various embodiments of the present invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the present invention. It should be understood that various alternatives to the embodiments of the present invention described herein may be employed in the practice of the present invention.

Claims

1. A control circuit for a tire balancing machine, characterized in that, include: Multiple capacitive touch sensors are used to generate finger proximity signals; The touch detection circuit has its input terminals connected to the front end of each capacitive touch sensor, which is used to convert the finger proximity signal generated by the capacitive touch sensor into a stable level signal. The signal conversion circuit has its input terminals connected to the output terminals of the touch detection circuit through isolation circuits, and its output terminals connected to different I / O pins of the main control circuit, for converting the level signal into matrix key signals. The signal conversion circuit includes a tri-state buffer. The output enable pin of the tri-state buffer is connected to the output terminal of the touch detection circuit through an isolation circuit. The output pin of the tri-state buffer is connected to the I / O pin of the main control circuit through a Zener diode. The anode of the Zener diode is connected to the I / O pin of the main control circuit, and the cathode is connected to the output pin of the tri-state buffer. The main control circuit is used to control the movement of the tire balancer based on the received matrix key signals. A power supply circuit is used to supply power to the touch detection circuit and the isolation circuit.

2. The control circuit for a tire balancing machine as described in claim 1, characterized in that, The input pin of the tri-state buffer is connected to the first power supply voltage via a pull-up resistor.

3. The control circuit for a tire balancing machine as described in claim 1, characterized in that, The power supply circuit includes a DC-DC converter and a linear regulator. The input voltage pin of the DC-DC converter is connected to a first supply voltage through a first inductor. The two ends of the first inductor are grounded through a first filter capacitor and a second filter capacitor, respectively. The output voltage pin of the DC-DC converter is connected to the input voltage pin of the linear regulator. The output voltage pin of the linear regulator is the output terminal of the power supply circuit.

4. The control circuit for a tire balancing machine as described in claim 3, characterized in that, The output voltage pin of the DC-DC converter is grounded through the third filter capacitor, and the output voltage pin of the linear regulator is grounded through the fourth filter capacitor.

5. The control circuit for a tire balancing machine as described in claim 3, characterized in that, The touch detection circuit is a capacitive touch controller. The touch key input pin of the capacitive touch controller is connected to the front end of the capacitive touch sensor. Its touch detection output signal pin is connected to the output enable terminal of the tri-state buffer through an isolation circuit. Its positive power supply pin is connected to the output voltage pin of the linear regulator. Its negative power supply pin is grounded. Its positive power supply pin is connected to its negative power supply pin through a filter capacitor.

6. The control circuit for a tire balancing machine as described in claim 5, characterized in that, The isolation circuit uses a dual-channel digital isolator. The logic input pin of the primary side of the dual-channel digital isolator is connected to the touch detection output signal pin of the capacitive touch controller. The logic output pin of the secondary side of the dual-channel digital isolator is connected to the output enable terminal of the tri-state buffer. The power supply pin of the dual-channel digital isolator is connected to the output voltage pin of the linear regulator.

7. The control circuit for a tire balancing machine as described in claim 6, characterized in that, The power supply pin of the dual-channel digital isolator is grounded through the sixth filter capacitor.

8. The control circuit for a tire balancing machine as described in claim 6, characterized in that, The logic output pins of the secondary side of the dual-channel digital isolator are connected to the output enable pin of the tri-state buffer via the first pin connector.

9. The control circuit for a tire balancing machine as described in claim 1, characterized in that, The front end of the capacitive touch sensor is grounded by adjusting the capacitor.

10. The control circuit for a tire balancing machine as described in any one of claims 1 to 8, characterized in that, The anode of the Zener diode is connected to the I / O pin of the main control circuit via a second pin connector.

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