Blower circuit of vehicle-mounted air conditioner

Abstract

The utility model discloses an air blower circuit of a vehicle-mounted air conditioner. The air blower circuit comprises a half-bridge drive circuit, a feedback filter circuit, an MOS tube, an air blower motor, a relay and an electronic controller, the MOS tube is connected in series in a main loop of the blower motor, and the electronic controller is connected with the MOS tube through the half-bridge driving circuit so as to drive the blower motor; the electronic controller is connected with the relay so as to connect or disconnect a main loop of the blower motor; and the electronic controller is connected with a driving end of the blower motor through the feedback filter circuit, and is used for collecting a driving signal of the main loop and converting the driving signal into a stable voltage signal so as to analyze the operation condition of the blower motor. By means of the circuit, the air inlet effect in the vehicle can be enhanced, and faster cooling is achieved; and meanwhile, the control of the air blower is more reliable.

Description

Technical Field

[0001] The utility model relates to the field of vehicle equipment, in particular to a blower circuit of a vehicle-mounted air conditioner. Background Art

[0002] The existing vehicle air-conditioning blower circuit uses an operational amplifier circuit to drive the MOS switch tube of the blower main circuit, which has weak driving ability, poor air intake effect in the car, and slow cooling.

[0003] The blower circuit of the existing vehicle air conditioner collects the feedback signal by directly collecting the PWM drive signal of the blower main circuit. However, the peak signal of the PWM drive signal will interfere with the collection of the feedback signal and affect the reliability of the blower control. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0005] A blower circuit for a vehicle air conditioner comprises a half-bridge drive circuit, a feedback filter circuit, a MOS tube, a relay, a blower motor and an electronic controller;

[0006] The MOS tube and the relay are connected in series in the main circuit of the blower motor;

[0007] The electronic controller is connected to the MOS tube through the half-bridge drive circuit to drive the blower motor; used to drive the relay to turn on or off the main circuit of the blower motor; and connected to a drive end of the blower motor through a feedback filter circuit;

[0008] The feedback filter circuit is used to collect the drive signal of the main circuit of the blower motor and filter and shape the drive signal into a stable voltage signal.

[0009] Furthermore, the feedback filter circuit includes a peak suppression circuit, a filter circuit and an operational amplifier shaping circuit which are sequentially connected from the input end to the output end.

[0010] Furthermore, the spike suppression circuit includes a first resistor, a second resistor and a first voltage regulator; the first resistor is connected in series between the input end and the output end of the spike suppression circuit; the second resistor and the first voltage regulator are connected in parallel and bridged between the output end of the spike suppression circuit and the ground.

[0011] Furthermore, the filtering circuit is a second-order RC filtering circuit, including a third resistor, a fourth resistor, a first capacitor and a second capacitor, the third resistor and the first capacitor constitute a first-stage RC filtering circuit; the fourth resistor and the second capacitor constitute a second-stage RC filtering circuit.

[0012] Furthermore, the operational amplifier shaping circuit includes a first operational amplifier unit and a second operational amplifier unit, wherein the first operational amplifier unit has a positive input connected to the output end of the filter circuit, and a negative input connected to the output end through a resistor; the output end of the first operational amplifier unit is connected to the positive input end of the second operational amplifier unit after being divided by a voltage divider resistor; the second operational amplifier unit has a negative input connected to its output end, and its output end is connected to the output end of the operational amplifier shaping circuit through a resistor, and is connected to the output end of the first operational amplifier unit through a resistor to form feedback.

[0013] Furthermore, the half-bridge driving circuit includes a half-bridge driving chip or a half-bridge driving unit in an H-bridge driving chip.

[0014] Furthermore, the electronic controller is a vehicle-mounted central controller.

[0015] The utility model achieves the following technical effects:

[0016] The utility model drives the MOS switch tube of the main circuit of the blower motor through a half-bridge drive circuit, has strong driving ability, can enhance the air intake effect in the car, and cool down faster; for the collection of the blower AD feedback signal, the PWM signal with spikes is absorbed by the operational amplifier shaping circuit and converted into a stable voltage signal that can be reliably identified by the MCU side, thereby realizing reliable control of the blower. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a circuit diagram of a vehicle air-conditioning blower of the utility model;

[0018] Figure 2 It is a circuit diagram of a half-bridge driving circuit of the utility model;

[0019] Figure 3 It is a circuit diagram of the feedback filter circuit of the utility model;

[0020] Figure 4 It is the wiring diagram of the blower module of the utility model. DETAILED DESCRIPTION

[0021] To further illustrate each embodiment, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in this field should be able to understand other possible implementations and advantages of the present invention.

[0022] The utility model is now further described in conjunction with the accompanying drawings and specific implementation methods.

[0023] like Figures 1 to 4As shown, the utility model provides a blower circuit of a vehicle air conditioner, which is composed of a half-bridge drive circuit 4, a blower module 3, an AD feedback circuit 2, an electronic controller 1, etc.

[0024] The blower module consists of a blower motor M1, a relay RLY1 and a MOS tube Q1.

[0025] The blower motor of the car air conditioner is a DC motor and adopts unidirectional control. MOS tube Q1 and relay RLY1 are connected in series in the main circuit of the blower motor M1. The relay RLY1 controls the on and off of the main circuit of the blower motor M1, and the MOS tube Q1 performs PWM modulation on the drive signal of the blower motor to control the speed of the blower.

[0026] Specifically, the gate of the MOS tube Q1 is connected to the output end of the half-bridge driving circuit 4; the source is grounded by grounding, and the drain is connected to the first driving end of the blower motor M1; the second driving end of the blower motor M1 is connected to the common terminal contact of the relay RLY1, and the normally open contact of the relay RLY1 is connected to the power supply KL30. One end of the driving coil of the relay RLY1 is connected to the power supply KL30, and the other end is connected to the electronic controller 1, and is controlled by the electronic controller 1, or grounded by an electronic switch to achieve manual control.

[0027] The use of an integrated half-bridge driver chip can simplify circuit design and ensure the reliability and stability of the DC motor drive circuit.

[0028] In this embodiment, the half-bridge drive circuit mainly includes an H-bridge drive chip MPQ6614. MPQ6614 is a dedicated DC motor drive chip. Since the blower of the car air conditioner only uses unidirectional control, only a set of upper and lower bridge arms of the H-bridge drive chip MPQ6614 are used to form a half-bridge drive circuit.

[0029] The electronic controller 1 generates a PWM signal to the half-bridge driver chip, which drives the MOS tube Q1 in the blower module 3 to form a PWM drive signal to control the speed of the blower motor M1. The half-bridge driver chip has a strong driving capability, which can enhance the air intake effect in the car and make the car cool down faster.

[0030] The first driving end of the blower motor M1 is connected to the input end of the AD feedback circuit 2, and the output end of the AD feedback circuit 2 is connected to the electronic controller 1. The AD feedback circuit 2 converts the PWM driving signal of the blower motor M1 into a stable voltage signal for the electronic controller 1 to diagnose.

[0031] In this embodiment, the AD feedback circuit 2 is composed of a series-connected voltage stabilizing circuit 21, an RC filter circuit 22, and an op amp shaping circuit 23. Among them, resistors R202, R203 and a voltage stabilizing tube ZD1 form the voltage stabilizing circuit 21; resistors R204, R205, capacitors C203, C204 form a two-stage RC filter circuit 22; and op amp units U2A, U2B, resistors R206, R207, R208, R209, R210 and capacitor C205 form the op amp shaping circuit 23.

[0032] The AD feedback loop 2 uses a voltage regulator ZD1 to absorb the PWM pulse spike, and then performs two-stage RC filtering and shaping. Finally, after being shaped by an operational amplifier, a stable voltage can be output for the electronic controller 1 to make a diagnosis, thereby realizing reliable control of the blower drive.

[0033] In a specific application, the electronic controller 1 is usually a central controller of the vehicle. The blower circuit of the vehicle air conditioner is directly controlled by the central controller.

[0034] Although the present invention has been specifically demonstrated and described in conjunction with the preferred embodiments, those skilled in the art should understand that various changes may be made to the present invention in form and detail without departing from the spirit and scope of the present invention as defined in the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A blower circuit for a vehicle air conditioner, characterized in that: It includes a half-bridge drive circuit, a feedback filter circuit, a MOS tube, a relay, a blower motor and an electronic controller; The MOS tube and the relay are connected in series in the main circuit of the blower motor; The electronic controller is connected to the MOS tube via the half-bridge driving circuit to drive the blower motor; Used to drive the relay to turn on or off the main circuit of the blower motor; Connected to a driving end of a blower motor via a feedback filter circuit; The feedback filter circuit is used to collect the drive signal of the main circuit of the blower motor and filter and shape the drive signal into a stable voltage signal.

2. The blower circuit of the vehicle air conditioner as claimed in claim 1, characterized in that: The feedback filter circuit comprises a peak suppression circuit, a filter circuit and an operational amplifier shaping circuit which are sequentially connected from the input end to the output end.

3. The blower circuit of the vehicle air conditioner as claimed in claim 2, characterized in that: The spike suppression circuit includes a first resistor, a second resistor and a first voltage regulator; the first resistor is connected in series between the input end and the output end of the spike suppression circuit; the second resistor and the first voltage regulator are connected in parallel and bridged between the output end of the spike suppression circuit and the ground.

4. The blower circuit of the vehicle air conditioner as claimed in claim 2, characterized in that: The filter circuit is a second-order RC filter circuit, including a third resistor, a fourth resistor, a first capacitor and a second capacitor. The third resistor and the first capacitor constitute a first-order RC filter circuit; the fourth resistor and the second capacitor constitute a second-order RC filter circuit.

5. The blower circuit of the vehicle air conditioner as claimed in claim 2, characterized in that: The operational amplifier shaping circuit includes a first operational amplifier unit and a second operational amplifier unit. The first operational amplifier unit has a positive input connected to the output end of the filter circuit, and a negative input connected to the output end through a resistor; the output end of the first operational amplifier unit is connected to the positive input end of the second operational amplifier unit after being divided by a voltage divider resistor; the second operational amplifier unit has a negative input connected to its output end, and its output end is connected to the output end of the operational amplifier shaping circuit through a resistor, and is connected to the output end of the first operational amplifier unit through a resistor to form feedback.

6. The blower circuit of the vehicle air conditioner as claimed in claim 1, characterized in that: The half-bridge driving circuit includes a half-bridge driving chip or a half-bridge driving unit in an H-bridge driving chip.

7. The blower circuit of the vehicle air conditioner as claimed in claim 1, characterized in that: The electronic controller is a vehicle-mounted central controller.

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