An analog DC motor control system for detecting the drive circuit of an air conditioning control panel

Abstract

The utility model provides a simulated DC motor control system for detecting the driving circuit of an air conditioning control board, wherein a DC motor driving signal receiving circuit is connected to the output signal end of the DC motor driving circuit of the control board under test; a receiving signal level conversion circuit is connected to the DC motor driving signal receiving circuit for converting the control signal level and inputting it to a central processing unit for identification processing; a feedback signal output circuit is connected to the central processing unit through an output signal level conversion circuit for converting the feedback signal processed by the central processing unit and sending it to the feedback input end of the DC motor driving circuit of the control board under test. The utility model provides a working circuit of a simulated DC motor, communicates with the DC motor driving circuit of the control board under test, and determines whether the circuit function of the control board under test is normal through the central processing unit, thereby simplifying the detection process of the DC motor driving circuit of the control board under test and avoiding the actual operation of the DC motor load.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioner detection, in particular to an analog DC motor control system for detecting a driving circuit of an air conditioner control panel. Background Art

[0002] Traditional household air conditioners are generally divided into two parts: indoor unit and outdoor unit. Each part has a fan motor, which is used to blow the cold or hot air inside the air conditioner out of the fuselage to provide heat or cold air to the room. For different energy efficiency levels or different product series, the common types of fan motors used are DC motors (direct current motors). The detection process of the DC motor drive circuit of the traditional control board is to plug the DC motor with the corresponding function into its motor drive interface when detecting the control board, observe whether the working state of the DC motor is normal or whether the fault code of the abnormal working of the DC motor is reported, so as to determine whether the drive and feedback circuits of the control board are normal. The final judgment of this detection method is made manually, which has certain uncertainties and is prone to missed detection or misjudgment, affecting the timeliness and stability of the production detection process. Once the DC motor drive circuit of the control board has functional abnormalities, it is also easy to cause damage to the motor load, and the motor load needs to be replaced in time, resulting in a great waste of material and time costs. Utility Model Content

[0003] To solve the above problems, the utility model aims to propose an analog DC motor control system for detecting the driving circuit of an air-conditioning control board. By setting a working circuit of an analog DC motor, communicating with the DC motor driving circuit of the control board under test, and judging whether the circuit function of the control board under test is normal through a central processing unit, the detection process of the DC motor driving circuit of the control board under test is simplified, and the actual operation of the DC motor load is avoided.

[0004] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0005] A simulated DC motor control system for detecting a driving circuit of an air-conditioning control panel, comprising a DC motor driving signal receiving circuit, a receiving signal level conversion circuit, an output signal level conversion circuit, a feedback signal output circuit and a central processing unit, wherein the DC motor driving signal receiving circuit is connected to the output signal end of the DC motor driving circuit of the tested control panel and is used to receive a control signal sent by the DC motor driving circuit of the tested control panel; the receiving signal level conversion circuit is connected to the DC motor driving signal receiving circuit and is used to convert the control signal level and input it to the central processing unit for identification processing; the feedback signal output circuit is connected to the central processing unit through the output signal level conversion circuit and is used to convert the feedback signal processed by the central processing unit and send it to the feedback input end of the DC motor driving circuit of the tested control panel after the feedback signal is converted.

[0006] Furthermore, the DC motor drive signal receiving circuit includes a receiving port CN1, a current limiting resistor R1, a forward clamping diode D1, a reverse clamping diode D2 and a resistor R2; the receiving port CN1 is connected in sequence to the current limiting resistor R1, the forward clamping diode, the reverse clamping diode D2 and the resistor R2 in parallel.

[0007] Furthermore, the receiving signal level conversion circuit includes a photocoupler U1, a pull-up resistor R3, a current limiting resistor R4, and a pull-down capacitor C1. The primary of the photocoupler U1 is connected to a reverse clamping diode D2 and a resistor R2 in parallel. The secondary of the photocoupler U1 is connected to the central processing unit via a current limiting resistor R4 and a pull-down capacitor C1 to form a resistor-capacitor low-pass filter circuit; the secondary signal port of the photocoupler U1 is connected to the pull-up resistor R3 and connected to +3.3V DC.

[0008] Furthermore, the output signal level conversion circuit includes a photocoupler U2, a pull-up resistor R7, and a driving transistor T1. The driving transistor T1 is connected between the primary of the photocoupler U2 and the central processing unit, and the primary input end of the photocoupler U2 is connected to the pull-up resistor R7 and connected to +3.3V DC.

[0009] Furthermore, the feedback signal output circuit includes an output port CN2, a protection resistor R5, and a current limiting resistor R6. The protection resistor R5 and the current limiting resistor R6 are connected in parallel between the secondary of the photocoupler U2 and the output port CN2.

[0010] Furthermore, the model of the forward clamping diode D1 and the reverse clamping diode D2 is GS1M, the model of the photoelectric coupler U1 is PC817C, the model of the photoelectric coupler U2 is PC817, and the model of the driving transistor T1 is LMUN2232.

[0011] Beneficial effect: The utility model sets a working circuit simulating a DC motor, communicates with the DC motor drive circuit of the control board under test, determines whether the circuit function of the control board under test is normal through the central processing unit, simplifies the detection process of the DC motor drive circuit of the control board under test, and avoids the actual operation of the DC motor load. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0013] Figure 1This is a schematic diagram of the structure and function of the analog DC motor control system for detecting the driving circuit of the air-conditioning control panel according to the embodiment of the utility model;

[0014] Figure 2 This is a circuit diagram of a simulated DC motor control system for detecting an air conditioning control panel drive circuit according to an embodiment of the utility model. DETAILED DESCRIPTION

[0015] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0016] Example 1

[0017] See also Figure 1-2 : An analog DC motor control system for detecting an air conditioning control board drive circuit, comprising a DC motor drive signal receiving circuit, a receiving signal level conversion circuit, an output signal level conversion circuit, a feedback signal output circuit and a central processing unit, wherein the DC motor drive signal receiving circuit is connected to the output signal end of the DC motor drive circuit of the control board under test, and is used to receive a control signal sent by the DC motor drive circuit of the control board under test; the receiving signal level conversion circuit is connected to the DC motor drive signal receiving circuit and is used to convert the control signal level and input it to the central processing unit for identification processing; the feedback signal output circuit is connected to the central processing unit through the output signal level conversion circuit and is used to convert the feedback signal processed by the central processing unit and send it to the feedback input end of the DC motor drive circuit of the control board under test after converting the level.

[0018] This embodiment sets up a working circuit of a simulated DC motor to communicate with the DC motor drive circuit of the control board under test, and uses the central processing unit to determine whether the circuit function of the control board under test is normal, thereby simplifying the detection process of the DC motor drive circuit of the control board under test and avoiding the actual operation of the DC motor load.

[0019] In a specific example, the DC motor drive signal receiving circuit includes a receiving port CN1, a current limiting resistor R1, a forward clamping diode D1, a reverse clamping diode D2 and a resistor R2; the receiving port CN1 is connected in sequence to the current limiting resistor R1, the forward clamping diode, the reverse clamping diode D2 and the resistor R2 in parallel.

[0020] In this embodiment, CN1 is connected in parallel with a reverse clamping diode D2 and a resistor R2 to protect the receiving signal level conversion circuit.

[0021] In a specific example, the receiving signal level conversion circuit includes a photocoupler U1, a pull-up resistor R3, a current limiting resistor R4, and a pull-down capacitor C1. The primary of the photocoupler U1 is connected to a reverse clamping diode D2 and a resistor R2 in parallel. The secondary of the photocoupler U1 is connected to a central processing unit via a current limiting resistor R4 and a pull-down capacitor C1 to form a resistor-capacitor low-pass filter circuit. The secondary signal port of the photocoupler U1 is connected to the pull-up resistor R3 and connected to +3.3V DC.

[0022] This embodiment can ensure the stability and correctness of the secondary output signal of the photocoupler U1.

[0023] In a specific example, the output signal level conversion circuit includes a photocoupler U2, a pull-up resistor R7, and a driving transistor T1. The driving transistor T1 is connected between the primary of the photocoupler U2 and the central processing unit, and the primary input end of the photocoupler U2 is connected to the pull-up resistor R7 and connected to +3.3V DC.

[0024] The driving transistor T1 of this embodiment is used to send a feedback square wave signal; the pull-up resistor R7 is used to protect the circuit and ensure stable conduction and cutoff of the driving transistor.

[0025] In a specific example, the feedback signal output circuit includes an output port CN2, a protection resistor R5, and a current limiting resistor R6. The protection resistor R5 and the current limiting resistor R6 are connected in parallel between the secondary of the photocoupler U2 and the output port CN2.

[0026] In a specific example, the forward clamping diode D1 and the reverse clamping diode D2 are of the model GS1M, the photoelectric coupler U1 is of the model PC817C, the photoelectric coupler U2 is of the model PC817, and the driving transistor T1 is of the model LMUN2232.

[0027] The diodes D1 and D2 in this example are of the GS1M type. D1 can protect the primary of the photocoupler U1 from reliable conduction in the high-level part of the square wave signal, and cooperate with the current limiting resistor R1, the reverse clamping diode D2, and the parallel resistor R2 to protect the photocoupler U1 from damage. The photocoupler U1 model is PC817C; the primary of the photocoupler U1 is turned on and off, and the square wave signal of the corresponding frequency and duty cycle can be obtained, which is input to the CPU and received and analyzed by the main control unit. The T1 transistor model is LMUN2232, which has its own current limiting and pull-down resistors to protect its internal structure from damage; U2 model is PC817, and the square wave signal sent by the CPU can have high and low level changes, which can cause T1 and U2 to be turned on and off, and obtain the square wave signal of the corresponding frequency and duty cycle, which is output to the signal receiving circuit of the control board under test. This forms a communication signal loop between the analog detection circuit and the control board under test, so as to analyze the signal and determine whether the circuit function of the control board under test is normal.

[0028] The process of the analog DC motor control circuit of this embodiment to detect the air conditioning control board drive circuit includes the following steps:

[0029] Step 1: Connect the DGND pin, the drive signal VSP pin, the feedback signal FB pin, the VCC-OUT (+15V) pin and the GND-OUT pin of the motor drive circuit of the control board to the receiving port CN1 and the output port CN2;

[0030] Step 2: During the test, the motor drive signal from the control board under test will be converted from the original high-level signal (+15V) to a low-level signal (+3.3V) that satisfies the CPU operation through the photoelectric coupler U1 of the simulated DC motor control circuit.

[0031] Step 3: After receiving the driving signal from the control board under test, the CPU will send a corresponding feedback signal to the control board under test. This signal is a low-level signal (+3.3V), which needs to be converted into a high-level signal (+15V) that meets the feedback circuit of the control board under test by the photoelectric coupler U2 of the detection circuit;

[0032] Step 4: During the detection process, if the CPU detects that the drive signal and the feedback signal of the control board under test reach a balance and no longer fluctuate, it is determined that the DC motor drive circuit of the control board under test is normal.

[0033] The working principle of this embodiment is as follows. First, the motor drive circuit port of the control board under test is connected to the ports CN1 and CN2. When the detection starts, according to the working principle of the DC motor, the control board under test sends a PWM square wave signal corresponding to the required speed to the receiving port CN1 of the analog detection circuit through the DC motor drive circuit. In the high-level effective voltage part of the square wave signal, the primary diode of the photocoupler U1 is turned on, and current flows through, so that the output end of the photocoupler U1 is turned on and outputs a low level; and in the low-level signal part of the square wave signal received by CN1, the current of the primary diode of the photocoupler is cut off, so that the output end of the photocoupler is closed and outputs a low level; thereby, the CPU unit of the analog circuit receives the converted motor drive signal of the control board under test. After receiving the speed driving square wave signal of the control board under test, the CPU unit sends a feedback square wave signal of the corresponding duty cycle according to the analyzed speed requirement to the reverse driving transistor T1 of the analog detection circuit. When the signal output by the CPU is in the high level part, the reverse driving transistor T1 outputs a low level; when the primary of the photoelectric coupler U2 detects the low level output by the transistor T1, the internal primary diode is turned on, and current flows through, so that the output end of the photoelectric coupler is turned on and outputs a low level; and when the signal output by the CPU is in the low level part, the reverse driving transistor T1 is turned off, and the output end is suspended; when the primary of the photoelectric coupler U2 detects the suspended signal output by the transistor T1, the internal primary diode current is turned off, so that the output end of the photoelectric coupler is turned off and the output is high level; thereby, the feedback square wave signal output by the CPU can be sent to the feedback receiving circuit of the control board under test; the CPU of the control board under test and the CPU of the analog detection circuit jointly analyze the input and output square wave signals, and when the required balance state is reached, the analog detection circuit CPU determines that the DC motor working circuit of the control board under test is normal.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A DC motor control system for detecting the driving circuit of an air conditioner control panel, characterized in that: It includes a DC motor drive signal receiving circuit, a receiving signal level conversion circuit, an output signal level conversion circuit, a feedback signal output circuit and a central processing unit. The DC motor drive signal receiving circuit is connected to the output signal end of the DC motor drive circuit of the control board under test, and is used to receive the control signal sent by the DC motor drive circuit of the control board under test; the receiving signal level conversion circuit is connected to the DC motor drive signal receiving circuit, and is used to convert the control signal level and input it to the central processing unit for identification processing; the feedback signal output circuit is connected to the central processing unit through the output signal level conversion circuit, and is used to convert the feedback signal processed by the central processing unit and send it to the feedback input end of the DC motor drive circuit of the control board under test.

2. The analog DC motor control system for detecting the driving circuit of the air conditioner control panel according to claim 1, characterized in that: The DC motor drive signal receiving circuit includes a receiving port CN1, a current limiting resistor R1, a forward clamping diode D1, a reverse clamping diode D2 and a resistor R2; the receiving port CN1 is sequentially connected to the current limiting resistor R1, the forward clamping diode, the reverse clamping diode D2 and the resistor R2 in parallel.

3. The analog DC motor control system for detecting the driving circuit of the air conditioner control panel according to claim 2, characterized in that: The receiving signal level conversion circuit includes a photocoupler U1, a pull-up resistor R3, a current limiting resistor R4, and a pull-down capacitor C1. The primary of the photocoupler U1 is connected to a reverse clamping diode D2 and a resistor R2 in parallel. The secondary of the photocoupler U1 is connected to a central processing unit via a current limiting resistor R4 and a pull-down capacitor C1 to form a resistor-capacitor low-pass filter circuit. The secondary signal port of the photocoupler U1 is connected to the pull-up resistor R3 and connected to +3.3V DC.

4. The analog DC motor control system for detecting the driving circuit of the air conditioner control panel according to claim 1, characterized in that: The output signal level conversion circuit includes a photocoupler U2, a pull-up resistor R7, and a driving transistor T1. The driving transistor T1 is connected between the primary of the photocoupler U2 and the central processing unit, and the primary input end of the photocoupler U2 is connected to the pull-up resistor R7 and connected to +3.3V DC.

5. The analog DC motor control system for detecting the driving circuit of the air conditioner control panel according to claim 4, characterized in that: The feedback signal output circuit includes an output port CN2, a protection resistor R5, and a current limiting resistor R6. The protection resistor R5 and the current limiting resistor R6 are connected in parallel between the secondary of the photocoupler U2 and the output port CN2.

Images