Ventilation control circuit, method and device

Abstract

The embodiment of the invention provides a ventilation control circuit, method and device. The circuit comprises a first triode, a second triode, a first resistor and a second resistor, wherein the first triode and the second triode form a current mirror; the base electrode of the first triode is connected to a first node, the collector electrode of the first triode is connected to the first node, and the emitter electrode of the first triode is connected to a first voltage end; the base electrode of the second triode is connected to the first node, the collector electrode of the second triode is connected to a second node, and the emitter electrode of the second triode is connected to the first voltage end; the first end of the first resistor is connected to an integrated circuit chip, and the second end of the first resistor is connected to the first node; the first end of the second resistor is connected to the first node, and the second end of the second resistor is connected to the first voltage end; and the second node is also connected to a fan. According to the embodiment of the invention, the second triode is prevented from being burnt out, so that the fan can work according to normal current requirements.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of automobile technology, and in particular to a ventilation control circuit, method and device. Background Art

[0002] With the advancement of automobile manufacturing technology, users have higher and higher requirements for automobile comfort. As an important part of the car, the seat is the main contact point between the driver and the passenger and the car. Seats with heating and ventilation functions can improve the driving and riding experience. The heating and ventilation device installed in the seat solves the problem of discomfort caused by damp or cold seats in wet or cold weather.

[0003] The ventilation device includes a fan for ventilation. The fan in the prior art has the problem of being unable to work according to normal current requirements. Summary of the invention

[0004] In view of this, embodiments of the present application provide a ventilation control circuit, method and device for enabling a fan to operate according to normal current requirements.

[0005] A first aspect provides a ventilation control circuit, comprising: a first triode, a second triode, a first resistor and a second resistor, wherein the first triode and the second triode form a current mirror;

[0006] The base of the first transistor is connected to the first node, the collector of the first transistor is connected to the first node, and the emitter of the first transistor is connected to the first voltage terminal;

[0007] The base of the second transistor is connected to the first node, the collector of the second transistor is connected to the second node, and the emitter of the second transistor is connected to the first voltage terminal;

[0008] A first end of the first resistor is connected to the integrated circuit chip, and a second end of the first resistor is connected to the first node;

[0009] A first end of the second resistor is connected to the first node, and a second end of the second resistor is connected to the first voltage terminal;

[0010] The second node is also connected to the wind turbine.

[0011] In a possible implementation, the ventilation control circuit further includes: a first capacitor;

[0012] A first terminal of the first capacitor is connected to the first node, and a second terminal of the first capacitor is connected to the first voltage terminal.

[0013] In a possible implementation, the ventilation control circuit further includes: a second capacitor;

[0014] A first terminal of the second capacitor is connected to the second node, and a second terminal of the second capacitor is connected to the first voltage terminal.

[0015] In a possible implementation manner, the first voltage terminal is a ground terminal.

[0016] In a possible implementation manner, the first transistor and the second transistor are of the same model.

[0017] A second aspect provides a ventilation control device, comprising: an integrated circuit chip, a fan, a fan power supply and a ventilation control circuit, wherein the ventilation control circuit is connected to the integrated circuit chip and the fan, and the fan is also connected to the fan power supply;

[0018] The ventilation control circuit adopts the ventilation control circuit in the above-mentioned first aspect or any possible implementation manner of the first aspect.

[0019] A third aspect provides a ventilation control method, the method being based on the ventilation control circuit of the first aspect; the method comprising:

[0020] The integrated circuit chip outputs a first control voltage;

[0021] The first resistor and the second resistor divide the first control voltage so that the voltage of the first node is the second control voltage;

[0022] Under the control of the second control voltage, the first transistor generates a first current, and the second transistor generates a second current under the action of the current mirror, so that the voltage of the second node is the third control voltage.

[0023] In a possible implementation manner, the first current and the second current are equal.

[0024] In a possible implementation, the ventilation control circuit further includes a first capacitor, a first end of the first capacitor is connected to the first node, and a second end of the first capacitor is connected to the first voltage end;

[0025] The method further comprises:

[0026] The first capacitor performs filtering processing on the second control voltage.

[0027] In a possible implementation, the ventilation control circuit further includes a second capacitor, a first end of the second capacitor is connected to the second node, and a second end of the second capacitor is connected to the first voltage end;

[0028] The method further comprises:

[0029] The second capacitor performs filtering processing on the third control voltage.

[0030] In the technical solution provided in the embodiment of the present application, the first transistor and the second transistor form a current mirror, the first end of the first resistor is connected to the integrated circuit chip, the second end of the first resistor is connected to the first node, the first end of the second resistor is connected to the first node, and the second end of the second resistor is connected to the first voltage end. In the embodiment of the present application, under the mirror effect of the current mirror, the second current of the second transistor is suppressed by the first current of the first diode, thereby preventing the second current of the second transistor from becoming larger, thereby avoiding the second transistor from being burned out, and enabling the fan to work according to normal current requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A schematic diagram of the structure of a ventilation control circuit provided in an embodiment of the present application;

[0033] Figure 2 A schematic structural diagram of a ventilation control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0035] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0036] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0037] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0038] Figure 1 A schematic diagram of a ventilation control circuit provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the ventilation control circuit may include a first transistor Q1, a second transistor Q2, a first resistor R1 and a second resistor R2, wherein the first transistor Q1 and the second transistor Q2 form a current mirror. The base of the first transistor Q1 is connected to the first node TP1, the collector of the first transistor Q1 is connected to the first node TP1, and the emitter of the first transistor Q1 is connected to the first voltage terminal; the base of the second transistor Q2 is connected to the first node TP1, the collector of the second transistor Q2 is connected to the second node TP2, and the emitter of the second transistor Q2 is connected to the first voltage terminal; the first end of the first resistor R1 is connected to the integrated circuit chip, and the second end of the first resistor R1 is connected to the first node TP1; the first end of the second resistor R2 is connected to the first node TP1, and the second end of the second resistor R2 is connected to the first voltage terminal; the second node TP2 is also connected to the fan.

[0039] like Figure 1 As shown, the base of the first transistor Q1 and the base of the second transistor Q2 are connected, and the first transistor Q1 and the second transistor Q2 form a current mirror.

[0040] As an optional solution, the ventilation control circuit further includes a first capacitor C1. A first end of the first capacitor C1 is connected to the first node TP1, and a second end of the first capacitor C1 is connected to the first voltage end.

[0041] As an optional solution, the ventilation control circuit further includes a second capacitor C2. A first end of the second capacitor C2 is connected to the second node TP2, and a second end of the second capacitor C2 is connected to the first voltage end.

[0042] In the present application embodiment, for example, Figure 1 As shown, the voltage of the first voltage terminal is the ground voltage, that is, the first voltage terminal can be the ground terminal GND. Therefore, the emitter of the first transistor Q1, the emitter of the second transistor Q2, the second end of the second resistor R2, the second end of the first capacitor C1 and the second end of the second capacitor C2 are connected to the ground terminal GND.

[0043] In the embodiment of the present application, the first triode Q1 and the second triode Q2 have the same model, and the parameters of the first triode Q1 and the second triode Q2 are the same. In other words, the first triode Q1 and the second triode Q2 can be the same triode. The first triode Q1 and the second triode Q2 have the same amplification factor.

[0044] In the embodiment of the present application, the first transistor Q1 and the second transistor Q2 may be NPN transistors.

[0045] In the embodiment of the present application, the first resistor R1 and the second resistor R2 are voltage-dividing resistors. As voltage-dividing resistors, the first resistor R1 and the second resistor R2 are connected in series and are disposed between the integrated circuit chip and the ground terminal GND.

[0046] As an optional solution, the integrated circuit chip may include a microcontroller unit (MCU). In the embodiment of the present application, the integrated circuit chip is described as an MCU.

[0047] Combine the following Figure 1 The working principle of the ventilation control circuit provided in the embodiment of the present application is described in detail.

[0048] The MCU outputs a first control voltage to the ventilation control circuit. For example, the first control voltage may be a first pulse width modulation (PWM) signal MCU_FANA_PWM2.

[0049] As voltage-dividing resistors, the first resistor R1 and the second resistor R2 can divide the first control voltage so that the voltage of the first node TP1 is the second control voltage. In other words, under the voltage-dividing effect of the first resistor R1 and the second resistor R2 on the first control voltage, the second control voltage is generated on the first node TP1.

[0050] The first transistor Q1 and the second transistor Q2 form a current mirror, the current on the current path 1 is the first current flowing through the first transistor Q1, the current on the current path 2 is the second current flowing through the second transistor Q2, and the current mirror can copy the first current on the current path 1 to the current path 2 to generate the second current on the current path 2. Then, under the action of the second control voltage, the first transistor Q1 generates the first current, and the second transistor Q2 generates the second current under the action of the current mirror, so that the voltage of the second node TP2 is the third control voltage. Specifically, when the first control voltage (i.e., the first PWM signal MCU_FANA_PWM2) is at a high level, the second control voltage is at a high level, and the first transistor Q1 is turned on and generates a first current under the control of the high-level second control voltage; the second transistor Q2 is turned on under the control of the high-level second control voltage, and under the action of the current mirror, the first current of the first transistor Q1 is copied to the second transistor Q2 so that the second transistor Q2 generates a second current, and the first transistor Q1 and the second transistor Q2 work in an amplification state at the same time. Since the amplification factors of the first transistor Q1 and the second transistor Q2 are the same, the second current flowing through the second transistor Q2 will be limited by the first current flowing through the first transistor Q1, that is, the current path 2 is limited through the current path 1, so that the first current and the second current are equal.

[0051] The voltage of the second node TP2 is the third control voltage, which can be the second PWM signal FAN_A_PWM2. The third control voltage is a pull-up power supply, and the specific voltage value of the pull-up power supply can be determined by the fan input. At this time, since the second transistor Q2 is turned on, the third control voltage on the second node TP2 (i.e., the second PWM signal FAN_A_PWM2) is at a low level. The second node TP2 forms a loop through the turned-on second transistor Q2 to the ground. In other words, the pull-up power supply flows back to the ground through the turned-on second transistor Q2, thereby starting the fan.

[0052] The first PWM signal MCU_FANA_PWM2 and the second PWM signal FAN_A_PWM2 have different amplitudes and different signal high and low changes. For example, when the first PWM signal MCU_FANA_PWM2 is high, the second PWM signal FAN_A_PWM2 is low; when the first PWM signal MCU_FANA_PWM2 is low, the second PWM signal FAN_A_PWM2 is high.

[0053] In the above ventilation control process, the first capacitor C1 can filter the second control voltage; the second capacitor C2 can filter the third control voltage.

[0054] Furthermore, when the first control signal is at a low level, the second control signal is at a low level, the second transistor Q2 is turned off, and the third control voltage at the second node TP2 is at a high level. Since the second transistor Q2 is turned off, the high level at the second node TP2 cannot reach the ground to form a loop, causing the fan to stop working.

[0055] In the technical solution provided in the embodiment of the present application, the first transistor and the second transistor form a current mirror, the first end of the first resistor is connected to the MCU, the second end of the first resistor is connected to the first node, the first end of the second resistor is connected to the first node, and the second end of the second resistor is connected to the first voltage end. In the embodiment of the present application, under the mirror effect of the current mirror, the second current of the second transistor is suppressed by the first current of the first diode, thereby preventing the second current of the second transistor from becoming larger, thereby avoiding the second transistor from being burned out, and enabling the fan to work according to normal current requirements.

[0056] In the embodiment of the present application, the fan control circuit and the fan driving circuit are isolated to prevent large current from being injected into the fan circuit in reverse, thereby preventing the transistors and MCU from being burned out. A current mirror is used for current control, so that the first control voltage output by the MCU passes through the current mirror formed by two transistors to output a third control voltage to the fan, so that the MCU pin is isolated from the pin driving the fan, thereby protecting the circuit from being damaged.

[0057] Figure 2 A schematic diagram of the structure of a ventilation control device provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the ventilation control device includes: an MCU, a fan, a fan power supply and a ventilation control circuit. The ventilation control circuit is connected to the MCU and the fan, and the fan is also connected to the fan power supply.

[0058] like Figure 2 As shown, the ventilation control circuit may include a first transistor Q1, a second transistor Q2, a first resistor R1 and a second resistor R2, wherein the first transistor Q1 and the second transistor Q2 form a current mirror. The base of the first transistor Q1 is connected to the first node TP1, the collector of the first transistor Q1 is connected to the first node TP1, and the emitter of the first transistor Q1 is connected to the first voltage terminal; the base of the second transistor Q2 is connected to the first node TP1, the collector of the second transistor Q2 is connected to the second node TP2, and the emitter of the second transistor Q2 is connected to the first voltage terminal; the first end of the first resistor R1 is connected to a microcontroller unit (MCU), and the second end of the first resistor R1 is connected to the first node TP1; the first end of the second resistor R2 is connected to the first node TP1, and the second end of the second resistor R2 is connected to the first voltage terminal; the second node TP2 is also connected to the fan.

[0059] For example, the fan power supply can be used to supply power to the fan. For example, the power supply voltage provided by the fan power supply can be 12V.

[0060] Combine the following Figure 2 The working principle of the ventilation control device in the embodiment of the present application is described in detail.

[0061] The MCU outputs a first control voltage to the ventilation control circuit. For example, the first control voltage may be a first PWM signal MCU_FANA_PWM2.

[0062] As voltage-dividing resistors, the first resistor R1 and the second resistor R2 can divide the first control voltage so that the voltage of the first node TP1 is the second control voltage. In other words, under the voltage-dividing effect of the first resistor R1 and the second resistor R2 on the first control voltage, the second control voltage is generated on the first node TP1.

[0063] The first transistor Q1 and the second transistor Q2 form a current mirror, the current on the current path 1 is the first current flowing through the first transistor Q1, the current on the current path 2 is the second current flowing through the second transistor Q2, and the current mirror can copy the first current on the current path 1 to the current path 2 to generate the second current on the current path 2. Then, under the action of the second control voltage, the first transistor Q1 generates the first current, and the second transistor Q2 generates the second current under the action of the current mirror, so that the voltage of the second node TP2 is the third control voltage. Specifically, when the first control voltage (i.e., the first PWM signal MCU_FANA_PWM2) is at a high level, the second control voltage is at a high level, and the first transistor Q1 is turned on and generates a first current under the control of the high-level second control voltage; the second transistor Q2 is turned on under the control of the high-level second control voltage, and under the action of the current mirror, the first current of the first transistor Q1 is copied to the second transistor Q2 so that the second transistor Q2 generates a second current, and the first transistor Q1 and the second transistor Q2 work in an amplification state at the same time. Since the amplification factors of the first transistor Q1 and the second transistor Q2 are the same, the second current flowing through the second transistor Q2 will be limited by the first current flowing through the first transistor Q1, so that the first current and the second current are equal.

[0064] The voltage of the second node TP2 is the third control voltage, which can be the second PWM signal FAN_A_PWM2. The third control voltage is a pull-up power supply, and the specific voltage value of the pull-up power supply can be determined by the fan input. At this time, since the second transistor Q2 is turned on, the third control voltage on the second node TP2 (i.e., the second PWM signal FAN_A_PWM2) is at a low level. The second node TP2 forms a loop to the ground through the turned-on second transistor Q2. In other words, the pull-up power supply flows back to the ground through the turned-on second transistor Q2, so that the fan is started under the drive of the power supply voltage provided by the fan power supply.

[0065] The first PWM signal MCU_FANA_PWM2 and the second PWM signal FAN_A_PWM2 have different amplitudes and different signal high and low changes. For example, when the first PWM signal MCU_FANA_PWM2 is high, the second PWM signal FAN_A_PWM2 is low; when the first PWM signal MCU_FANA_PWM2 is low, the second PWM signal FAN_A_PWM2 is high.

[0066] In the above ventilation control process, the first capacitor C1 can filter the second control voltage; the second capacitor C2 can filter the third control voltage.

[0067] Furthermore, when the first control signal is at a low level, the second control signal is at a low level, the second transistor Q2 is turned off, and the third control voltage at the second node TP2 is at a high level. Since the second transistor Q2 is turned off, the high level at the second node TP2 cannot reach the ground to form a loop, causing the fan to stop working.

[0068] In the technical solution provided in the embodiment of the present application, the first transistor and the second transistor form a current mirror, the first end of the first resistor is connected to the MCU, the second end of the first resistor is connected to the first node, the first end of the second resistor is connected to the first node, and the second end of the second resistor is connected to the first voltage end. In the embodiment of the present application, under the mirror effect of the current mirror, the second current of the second transistor is suppressed by the first current of the first diode, thereby preventing the second current of the second transistor from becoming larger, thereby avoiding the second transistor from being burned out, and enabling the fan to work according to normal current requirements.

[0069] In the embodiment of the present application, the fan control circuit and the fan driving circuit are isolated to prevent large current from being injected into the fan circuit in reverse, thereby preventing the transistors and MCU from being burned out. A current mirror is used for current control, so that the first control voltage output by the MCU passes through the current mirror formed by two transistors to output a third control voltage to the fan, so that the MCU pin is isolated from the pin driving the fan, thereby protecting the circuit from being damaged.

[0070] The present application also provides a ventilation control method based on Figure 1 The ventilation control circuit shown. The method comprises:

[0071] The MCU outputs a first control voltage; the first resistor and the second resistor divide the first control voltage so that the voltage at the first node is the second control voltage; under the control of the second control voltage, the first transistor generates a first current, and the second transistor generates a second current under the action of the current mirror so that the voltage at the second node is the third control voltage. The first current and the second current are equal.

[0072] As an optional solution, the method may further include: the first capacitor performs filtering processing on the second control voltage.

[0073] As an optional solution, the method may further include: the second capacitor performs filtering processing on the third control voltage.

[0074] In the technical solution provided in the embodiment of the present application, the first transistor and the second transistor form a current mirror, the first end of the first resistor is connected to the MCU, the second end of the first resistor is connected to the first node, the first end of the second resistor is connected to the first node, and the second end of the second resistor is connected to the first voltage end. In the embodiment of the present application, under the mirror effect of the current mirror, the second current of the second transistor is suppressed by the first current of the first diode, thereby preventing the second current of the second transistor from becoming larger, thereby avoiding the second transistor from being burned out, and enabling the fan to work according to normal current requirements.

[0075] In the embodiment of the present application, the fan control circuit and the fan driving circuit are isolated to prevent large current from being injected into the fan circuit in reverse, thereby preventing the transistors and MCU from being burned out. A current mirror is used for current control, so that the first control voltage output by the MCU passes through the current mirror formed by two transistors to output a third control voltage to the fan, so that the MCU pin is isolated from the pin driving the fan, thereby protecting the circuit from being damaged.

[0076] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A ventilation control circuit, characterized in that: include: A first triode, a second triode, a first resistor and a second resistor, wherein the first triode and the second triode form a current mirror; The base of the first transistor is connected to the first node, the collector of the first transistor is connected to the first node, and the emitter of the first transistor is connected to the first voltage terminal; The base of the second transistor is connected to the first node, the collector of the second transistor is connected to the second node, and the emitter of the second transistor is connected to the first voltage terminal; A first end of the first resistor is connected to the integrated circuit chip, and a second end of the first resistor is connected to the first node; A first end of the second resistor is connected to the first node, and a second end of the second resistor is connected to the first voltage terminal; The second node is also connected to the wind turbine.

2. The circuit according to claim 1, characterized in that The ventilation control circuit further includes: a first capacitor; A first terminal of the first capacitor is connected to the first node, and a second terminal of the first capacitor is connected to the first voltage terminal.

3. The circuit according to claim 1, characterized in that The ventilation control circuit further includes: a second capacitor; A first terminal of the second capacitor is connected to the second node, and a second terminal of the second capacitor is connected to the first voltage terminal.

4. The circuit according to claim 1, characterized in that The first voltage terminal is a ground terminal.

5. The circuit according to claim 1, characterized in that The first transistor and the second transistor are of the same model.

6. A ventilation control device, characterized in that: include: An integrated circuit chip, a fan, a fan power supply and a ventilation control circuit, wherein the ventilation control circuit is connected to the integrated circuit chip and the fan, and the fan is also connected to the fan power supply; The ventilation control circuit adopts the ventilation control circuit described in any one of claims 1 to 5 above.

7. A ventilation control method, characterized in that: The method is based on the ventilation control circuit according to claim 1; the method comprises: The integrated circuit chip outputs a first control voltage; The first resistor and the second resistor divide the first control voltage so that the voltage of the first node is the second control voltage; Under the control of the second control voltage, the first transistor generates a first current, and the second transistor generates a second current under the action of the current mirror, so that the voltage of the second node is the third control voltage.

8. The method according to claim 7, characterized in that The first current and the second current are equal.

9. The method according to claim 7, characterized in that: The ventilation control circuit further includes a first capacitor, a first end of the first capacitor is connected to the first node, and a second end of the first capacitor is connected to the first voltage end; The method further comprises: The first capacitor performs filtering processing on the second control voltage.

10. The method according to claim 7, characterized in that The ventilation control circuit further includes a second capacitor, a first end of the second capacitor is connected to the second node, and a second end of the second capacitor is connected to the first voltage end; The method further comprises: The second capacitor performs filtering processing on the third control voltage.

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