A motor monitoring method for a food processor

Abstract

The embodiment of the application discloses a motor monitoring method of a food processor, the food processor comprising a main control circuit and a power supply, a switch, a detection circuit and a motor driving circuit connected in sequence; a detection signal output end of the detection circuit is connected with a signal input end of the main control circuit, and the method comprises that: the switch comprises a closed state and an open state; when the switch is in the open state, a voltage value of the signal input end which can determine whether the motor has a voltage endurance problem is acquired; when the voltage value is zero, it is determined that the motor does not have a voltage endurance problem; when the voltage value is greater than zero and less than a preset voltage threshold, it is determined that the motor has a voltage endurance problem. Through the embodiment scheme, the voltage endurance problem of the motor can be detected in time and effectively, and treatment can be made in time. The motor voltage endurance state is monitored when the switch is open, and the motor itself working state has less influence, so that the monitoring is more accurate.

Description

[0001] This application is a divisional application in accordance with the Implementing Regulations of the Patent Law Article 42, the original application is the application number 201910547284.9, the name is "a motor monitoring method of food processor" submitted on June 24, 2019. TECHNICAL FIELD

[0002] The embodiment of the application relates to motor detection technology, in particular to a motor monitoring method of food processor. BACKGROUND

[0003] At present, the motor used in food processor (such as soybean milk machine) is mostly brush motor, the motor works by using carbon brush commutation, and a large amount of carbon powder will be generated due to carbon brush wear after long time work, and the carbon powder will cause poor voltage resistance of the motor, serious sparking during work, and even cause trip and other abnormalities. At present, there is no effective detection scheme for the problem of poor voltage resistance of the motor. SUMMARY

[0004] The embodiment of the application provides a motor monitoring method of food processor, which can timely and effectively detect the poor voltage resistance phenomenon of the motor and timely make treatment.

[0005] In order to achieve the purpose of the embodiment of the application, the embodiment of the application provides a motor monitoring method of food processor, wherein the food processor comprises a main control circuit and a power supply, a switch, a detection circuit and a motor driving circuit connected in sequence; the detection signal output end of the detection circuit is connected with the signal input end of the main control circuit, the first end of the switch is connected with the zero line of the power supply, and the second end is connected with the detection signal input end of the detection circuit; the method comprises:

[0006] The switch comprises a closed state and an open state;

[0007] In the open state of the switch, the voltage value of the signal input end which can determine whether the motor appears poor voltage resistance is acquired;

[0008] When the voltage value is zero, it is determined that the motor does not appear poor voltage resistance phenomenon;

[0009] When the voltage value is greater than zero and less than a preset voltage threshold, it is determined that the motor appears poor voltage resistance phenomenon.

[0010] In the exemplary embodiment of the application, the method further comprises: controlling the closing and opening of the switch by opening and closing the cup cover of the food processor.

[0011] In the exemplary embodiment of the application, the switch is a magnetic control micro switch.

[0012] In the example embodiment of the present application, the detection circuit comprises a diode, a first voltage dividing resistor, a second voltage dividing resistor, a third voltage dividing resistor, a fourth voltage dividing resistor, a triode, a first filter capacitor, a second filter capacitor and a pull-up resistor.

[0013] In the example embodiment of the present application, the diode, the first voltage dividing resistor, the second voltage dividing resistor, the third voltage dividing resistor and the fourth voltage dividing resistor are connected in series; an anode of the diode is a detection signal input end of the detection circuit, a first end of the fourth voltage dividing resistor is connected with the third voltage dividing resistor, and a second end is connected with a signal ground SGND;

[0014] The first filter capacitor is connected in parallel with the fourth voltage dividing resistor.

[0015] An emitter of the triode is connected with the first end of the fourth voltage dividing resistor, a base is connected with the SGND, and a collector is connected with a first end of the pull-up resistor;

[0016] A second end of the pull-up resistor is connected with a power supply; and the second filter capacitor is connected in parallel between the base and the collector of the triode.

[0017] A signal input end of the main control circuit is connected with the collector.

[0018] The example embodiment of the present application can have the following beneficial effects.

[0019] 1. The food processor of the example embodiment of the present application can comprise a main control circuit and a power supply, a switch, a detection circuit and a motor driving circuit connected in series; a detection signal output end of the detection circuit is connected with a signal input end of the main control circuit; and the method can comprise: the switch comprises a closed state and an open state; when the switch is in the open state, a voltage value of the signal input end is acquired to determine whether the motor has a voltage endurance problem; when the voltage value is zero, it is determined that the motor does not have a voltage endurance problem; and when the voltage value is greater than zero and less than a preset voltage threshold, it is determined that the motor has a voltage endurance problem. The voltage endurance problem of the motor can be determined by identifying the AD value of the signal of the detection circuit. Further, the closed state and the open state of the switch are utilized; generally, when the switch is in the closed state, the food processor is in a normal working state, and the voltage endurance of the motor is monitored to ensure that the food processor is always in a normal working state; and only when the switch is in the open state, the voltage endurance of the motor is detected, so as to reduce the influence of the working state of the motor on the accuracy of the voltage endurance detection, and further improve the accuracy of the voltage endurance detection.

[0020] 2. The switch in this embodiment of the invention is a magnetically controlled micro switch; the method may further include: controlling the opening and closing of the magnetically controlled micro switch by opening and closing the lid of the food processor. This embodiment ensures that the magnetically controlled micro switch performs both closing and opening actions each time pulping occurs, thereby allowing for the detection of the motor's withstand voltage during each pulping process.

[0021] 3. The food processing machine of this embodiment may include: a main control circuit and a power supply, a switch, a detection circuit, and a motor drive circuit connected in sequence; the detection signal output terminal of the detection circuit is connected to the signal input terminal of the main control circuit, and the method may include: after the switch is closed, acquiring the detection signal of the signal input terminal; determining the signal parameters of the detection signal; the signal parameters include any one or more of the following: duty cycle, pulse width, low level duration, and detected voltage value; determining whether the motor has a voltage withstand failure phenomenon based on the change of the signal parameters; when it is determined that the motor has a voltage withstand failure phenomenon, processing according to a preset processing scheme; the preset processing scheme includes any one or more of the following: alarm, controlling the motor to stop running, and cutting off the power supply to the motor. Through this embodiment, the voltage withstand failure phenomenon of the motor can be detected in a timely and effective manner, and timely processing can be carried out.

[0022] 4. In this embodiment of the invention, when the signal parameter is the duty cycle, determining whether the motor has a voltage withstand failure based on the change of the signal parameter may include: determining that the motor has a voltage withstand failure when the duty cycle decreases; and determining that the motor has not a voltage withstand failure when the duty cycle does not change. This embodiment is simple and easy to implement.

[0023] 5. In this embodiment of the invention, when the signal parameter is the pulse width, determining whether the motor has a voltage withstand failure based on the change of the signal parameter may include: determining that the motor has a voltage withstand failure when the pulse width is greater than a preset pulse width threshold; and determining that the motor does not have a voltage withstand failure when the pulse width is less than or equal to the pulse width threshold. This embodiment has high detection accuracy, ensuring correct detection of the motor's voltage withstand problem and avoiding further abnormalities caused by continued use after a voltage withstand failure.

[0024] 6. In this embodiment of the invention, when the signal parameter is the duration of the low-level signal, determining whether the motor has a voltage withstand failure based on the change of the signal parameter may include: determining that the motor has a voltage withstand failure when the duration of the low-level signal is less than a preset duration threshold; and determining that the motor does not have a voltage withstand failure when the duration of the low-level signal is greater than or equal to the duration threshold. Through this embodiment, the detection circuit can be implemented using a zero-crossing detection circuit, and the voltage withstand failure of the motor can be detected by detecting the zero-crossing signal.

[0025] 7. In this embodiment of the invention, the first end of the switch is connected to the neutral wire of the power supply, and the second end is connected to the detection signal input terminal of the detection circuit; a rectifier bridge is provided in the motor drive circuit, and the detection signal input terminal is directly connected to the rectifier bridge. Through this embodiment, the power supply can be disconnected by turning off the switch, thereby switching the input of the detection circuit to the motor circuit.

[0026] Other features and advantages of embodiments of the present invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of embodiments of the invention may be realized and obtained by means of the structures particularly pointed out in the description and the drawings. Attached Figure Description

[0027] The accompanying drawings are used to provide a further understanding of the technical solutions of the embodiments of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the embodiments of the present invention and do not constitute a limitation on the technical solutions of the embodiments of the present invention.

[0028] Figure 1 This is a flowchart of the motor monitoring method for a food processing machine according to an embodiment of the present invention;

[0029] Figure 2 This is a block diagram of the food processing machine according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the detection circuit according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the equivalent circuit when the switch is closed according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the base voltage of the transistor and the signal input voltage of the main control circuit in an embodiment of the present invention.

[0033] Figure 6 This is a schematic diagram of the equivalent circuit when the motor has poor withstand voltage according to an embodiment of the present invention;

[0034] Figure 7A schematic diagram of the detection circuit of the embodiment of the present application when the detection circuit is an AD sampling circuit;

[0035] Figure 8 A schematic diagram of the detection circuit of the embodiment of the present application when the current of the motor with poor voltage resistance flows into the detection circuit through the shell. DETAILED DESCRIPTION

[0036] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in any manner without conflict.

[0037] The steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Moreover, although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown.

[0038] Embodiment One

[0039] The embodiment of the present application provides a motor monitoring method of a food processor, the food processor can include a master control circuit 5 and a power supply 2, a switch 1, a detection circuit 3 and a motor driving circuit 4 connected in sequence; a detection signal output end of the detection circuit 3 is connected with a signal input end of the master control circuit 5, as shown in Figure 1 、 Figure 2 The method can include S101-S104:

[0040] S101, after the switch is turned on, a detection signal of the signal input end is acquired;

[0041] S102, a signal parameter of the detection signal is determined; the signal parameter includes any one or more of the following: duty ratio, pulse width, low-level duration and detected voltage value;

[0042] S103, whether the motor has a voltage resistance failure phenomenon is determined according to a change of the signal parameter;

[0043] S104, when it is determined that the motor has a voltage resistance failure phenomenon, a preset processing scheme is used for processing; the preset processing scheme includes any one or more of the following: alarming, controlling the motor to stop running and cutting off the power supply of the motor.

[0044] In the exemplary embodiment of the present application, as Figure 3As shown, the detection circuit can comprise: a diode D1, a first voltage dividing resistor R1, a second voltage dividing resistor R2, a third voltage dividing resistor R3, a fourth voltage dividing resistor R4, a triode Q1, a first filter capacitor C1, a second filter capacitor C2 and a pull-up resistor R5;

[0045] The diode D1, the first voltage dividing resistor R1, the second voltage dividing resistor R2, the third voltage dividing resistor R3 and the fourth voltage dividing resistor R4 are connected in series; the anode of the diode D1 is the detection signal input end of the detection circuit, the first end of the fourth voltage dividing resistor R4 is connected with the third voltage dividing resistor R3, and the second end is connected with a signal ground SGND;

[0046] The first filter capacitor C1 is connected in parallel with the fourth voltage dividing resistor R4;

[0047] The emitter B of the triode Q1 is connected with the first end of the fourth voltage dividing resistor R4, the base E is connected with the SGND, and the collector C is connected with the first end of the pull-up resistor R5;

[0048] The second end of the pull-up resistor R5 is connected with a power supply; the second filter capacitor C2 is connected in parallel between the base and the collector of the triode;

[0049] The signal input end Z of the main control circuit is connected with the collector C.

[0050] In the exemplary embodiment of the present application, when the switch is closed during the normal operation of the food processor, the power supply is 220V with respect to N (power zero line) of the signal ground SGND, the power supply is half-wave rectified through D1, is divided through R4, and then turns on and off the triode Q1, so that a square wave with a frequency of 50HZ and a duty cycle of 50% is formed at the signal input end Z of the main control circuit; after the switch is turned off, the power supply is disconnected, and the signal at Z is a continuous high level. After the motor has poor voltage resistance, a large resistance will be generated between the shell and the internal lead wire, which will lead to the change of the resistance of the voltage dividing circuit and the change of the detection signal. At this time, the signal at Z is a square wave signal with a frequency of 50HZ and a duty cycle less than 50%. Based on the above principle, the duty cycle, pulse width, low level duration (such as zero voltage duration) or voltage difference of the detection signal can be identified by the main control circuit to determine whether the motor has poor voltage resistance.

[0051] In the exemplary embodiment of the present application, the detection of the voltage resistance problem of the motor avoids the use of the motor with poor voltage resistance to cause other abnormalities.

[0052] Embodiment two

[0053] The embodiment is based on the embodiment one, and gives the specific implementation of determining whether the motor has the voltage endurance bad phenomenon according to the change of the signal parameter.

[0054] In the exemplary embodiment of the application, when the signal parameter is the duty cycle, the determination of whether the motor has the voltage endurance bad phenomenon according to the change of the signal parameter can include:

[0055] When the duty cycle decreases, it is determined that the motor has the voltage endurance bad phenomenon.

[0056] When the duty cycle does not change, it is determined that the motor does not have the voltage endurance bad phenomenon.

[0057] In the exemplary embodiment of the application, when the food processor is in normal operation, the switch is closed, the signal input end Z of the main control circuit forms a square wave with a frequency of 50HZ and a duty cycle of 50%; after the motor has the voltage endurance bad phenomenon, a large resistance is generated between the shell and the internal wire, which leads to the change of the resistance of the voltage division circuit and the change of the detection signal, and at this time, the signal at Z is a square wave signal with a frequency of 50HZ and a duty cycle less than 50%. Therefore, directly detecting the duty cycle of the signal detected at the Z port can determine whether the motor has the voltage endurance bad phenomenon, which is simple and easy to implement.

[0058] In the exemplary embodiment of the application, when the signal parameter is the pulse width, the determination of whether the motor has the voltage endurance bad phenomenon according to the change of the signal parameter can include:

[0059] When the pulse width is greater than a preset pulse width threshold, it is determined that the motor has the voltage endurance bad phenomenon.

[0060] When the pulse width is less than or equal to the pulse width threshold, it is determined that the motor does not have the voltage endurance bad phenomenon.

[0061] In the exemplary embodiment of the application, when the signal parameter is the low-level duration, the determination of whether the motor has the voltage endurance bad phenomenon according to the change of the signal parameter can include:

[0062] When the low-level duration is less than a preset duration threshold, it is determined that the motor has the voltage endurance bad phenomenon.

[0063] When the low-level duration is greater than or equal to the duration threshold, it is determined that the motor does not have the voltage endurance bad phenomenon.

[0064] In the exemplary embodiment of the application, when the switch (such as a magnetic control micro switch) is closed, its equivalent circuit is as follows: Figure 4As shown, when the voltage is 220V, the power voltage is half-wave rectified by D1, and then the voltage UB at the base B is obtained by dividing the voltage by R4, R1, R2 and R3 to control the conduction of the triode. When the positive half-wave, , the negative half-wave =0, the waveform is as shown by the curve in Figure 5 . When the voltage is greater than the conduction voltage 0.7V of the triode, the triode is turned on, and when the voltage is less than 0.7V, the triode is turned off. The starting conduction time t=T1 can be calculated by =0.7V. When the triode is turned on, the Z terminal outputs a low level, and when the triode is turned off, the Z terminal outputs a high level. The waveform of the Z terminal output is as shown by the straight line in . The low level duration t1=(0.01-2T1)S and the high level duration t2=(0.01+2T1)S can be collected by the main control circuit. Figure 5 In the exemplary embodiment of the present application, when the motor has poor voltage resistance, the equivalent circuit is as shown in . The voltage dividing circuit has the resistance R of the motor connected in series on the basis of the original circuit. When the positive half-wave,

[0065] , the negative half-wave Figure 6 =0, the triode conduction time is shortened, i.e. =0.7V, and the starting conduction time t=T2 can be calculated. The low level duration t3=(0.01-2T2)S and the high level duration t4=(0.01+2T2)S can be collected by the main control circuit. Since R is much greater than the other resistances, t3 is much smaller than t1, and the threshold T (T2>T>T1) is set. When the low level is detected and the duration is greater than (0.01-2T)S, i.e., the length threshold, or the high level is detected and the duration is less than (0.01+2T)S, i.e., the pulse width threshold, it is considered that the detection signal is normal, otherwise, it is considered that the detection signal is abnormal due to poor voltage resistance of the motor. In the exemplary embodiment of the present application, the problem of poor voltage resistance of the motor is indirectly identified by judging the low level duration and the pulse width.

[0066] Embodiment Three

[0067] The embodiment is based on the embodiment one, and the method further comprises that the switch comprises a closed state and an open state; only when the switch is in the open state, the voltage value of the signal input end which can determine whether the motor has poor voltage resistance is obtained, and the specific implementation mode of determining whether the motor has poor voltage resistance phenomenon according to the change of the signal parameter, i.e., the motor poor voltage resistance can be identified by the AD detection mode of the detection signal.

[0068] The embodiment is based on the embodiment one, and the method further comprises that the switch comprises a closed state and an open state; only when the switch is in the open state, the voltage value of the signal input end which can determine whether the motor has poor voltage resistance is obtained, and the specific implementation mode of determining whether the motor has poor voltage resistance phenomenon according to the change of the signal parameter, i.e., the motor poor voltage resistance can be identified by the AD detection mode of the detection signal. ​

[0069] In the exemplary embodiment of the present application, when the switch is in the off state and the signal parameter is the voltage value, the determination of whether the motor has a voltage endurance problem according to the change of the signal parameter can include:

[0070] when the voltage value is greater than zero and less than a preset voltage threshold, it is determined that the motor has a voltage endurance problem;

[0071] when the voltage value is zero, it is determined that the motor does not have a voltage endurance problem.

[0072] In the exemplary embodiment of the present application, when the detection circuit is an analog-to-digital (AD) sampling circuit, the circuit diagram can be as shown in Figure 7 .

[0073] In the exemplary embodiment of the present application, the detection circuit can include a diode D2, a fifth voltage dividing resistor R5, a sixth voltage dividing resistor R6, a seventh voltage dividing resistor R7, an eighth voltage dividing resistor R8, a third filter capacitor EC1, and a fourth filter capacitor C3.

[0074] Among them, the diode D2, the fifth voltage dividing resistor R5, the sixth voltage dividing resistor R6, the seventh voltage dividing resistor R7 and the eighth voltage dividing resistor R8 are connected in series; the anode of the diode D2 is the detection signal input end of the detection circuit, the first end of the eighth voltage dividing resistor R8 is connected with the seventh voltage dividing resistor R7, and the second end is connected with the signal ground SGND.

[0075] The third filter capacitor EC1 and the fourth filter capacitor C3 are both connected in parallel with the eighth voltage dividing resistor R8.

[0076] The AD signal sampling end VOL_AD of the main control circuit is connected with the first end of the eighth voltage dividing resistor R8.

[0077] In the exemplary embodiment of the present application, when the switch is closed, the power supply is rectified by D2, then divided by R8, and the voltage value is obtained by EC1 filtering , and the main control circuit samples the voltage at this point by VOL_AD. Since the input port voltage of the main control circuit (such as a single-chip microcomputer) generally needs to be less than 5V, i.e. the maximum input voltage is 275*0.45*R8 / 220K<5, then R8<8.8K, and the R8 in the present embodiment can be taken as 3.3KΩ.

[0078] In the exemplary embodiment of the present application, when the motor is normal, the voltage at VOL_AD is =0.45U*3.3 / 220, U is the current mains voltage, when the switch is opened, there is no voltage input, and the voltage at VOL_AD is =0.

[0079] In the exemplary embodiment of the present application, when the motor has poor voltage resistance, the voltage at VOL_AD is consistent with that in normal time when the switch is closed, and is not in the monitoring state; when the switch is opened, the voltage is connected in series through the motor shell, and the voltage at VOL_AD is 0.45U*3.3 / (220+R), U is the current mains voltage, and R is the equivalent resistance when the motor has poor voltage resistance. A voltage threshold VT is set, and the voltage at VOL_AD satisfies 0 <VT, it can be judged that the motor has poor voltage resistance. Since the current mains voltage U is allowed to be in the range of 155V-275V, VT needs to be less than 0.45*155*3.3 / (220+R)=1V, and needs to be greater than 0.45*275*3.3 / (220+R)=0.33V, therefore, the embodiment can take VT=0.7V. In this way, the monitoring of the poor voltage resistance of the motor is realized.

[0080] In the exemplary embodiment of the present application, when the signal AD value of the detection circuit is recognized, it can be judged that the motor has poor voltage resistance when the detection AD value is lower than the set voltage threshold.

[0081] Embodiment Four

[0082] This embodiment gives a specific connection embodiment of the detection circuit on the basis of any of the above embodiments.

[0083] In the exemplary embodiment of the present application, as shown in the figure, the first end of the switch 1 is connected with the zero line of the power supply 2, and the second end is connected with the detection signal input end of the detection circuit 3. Figure 3

[0084] The motor drive circuit 4 is provided with a rectifier bridge 41, and the detection signal input end is directly connected with the rectifier bridge 41.

[0085] In the exemplary embodiment of the present application, the input end of the detection circuit needs to be directly connected with the rectifier bridge 41 of the motor 6, and the controllable switch 1 needs to be added between the input end and the zero line, so as to disconnect the input of the zero line end power supply during detection.

[0086] In the exemplary embodiment of the present application, by disconnecting the switch 1, the connection between the detection circuit 3 and the power supply 2 is disconnected, so as to switch the input of the detection circuit to the motor drive circuit 4.

[0087] Embodiment Five

[0088] This embodiment gives an embodiment scheme of the closing and opening of the switch controlled by the opening and closing of the upper cover (such as a magnetic micro switch) on the basis of any of the above embodiments.

[0089] ​​​In the exemplary embodiments of the present application, the switch is a magnetic microswitch; the method can further comprise: controlling the closing and opening of the magnetic microswitch by the opening and closing of the food processor cup cover.

[0090] In the exemplary embodiments of the present application, a magnet can be installed in the cup cover, when the cup cover is closed, the magnet is close to the magnetic microswitch, causing the magnetic microswitch to close; when the cup cover is opened, the magnet is away from the magnetic microswitch, causing the magnetic microswitch to open.

[0091] In the exemplary embodiments of the present application, since the food processor needs to perform the operation of opening and closing the cup cover each time the food is processed, it can ensure that the magnetic microswitch has the action of closing and opening each time the food is processed, and the motor withstand voltage problem can be detected when the magnetic microswitch is opened.

[0092] Embodiment Six

[0093] This embodiment is based on any of the above embodiments, and gives an embodiment scheme in which the power supply (such as a 9V power supply) of the main control circuit (such as a single-chip microcomputer) is loaded on the live wire.

[0094] In the exemplary embodiments of the present application, the power input end of the main control circuit is connected with the live wire output end of the power supply, so that the power supply of the main control circuit is loaded on the live wire of the power supply.

[0095] In the exemplary embodiments of the present application, the motor shell needs to be grounded (GND) at present, since the zero line and the ground potential are almost equal, and the potential of 9v to the signal ground SGND is 9v, when the 9v is loaded on the live wire, the voltage of GND to SGND is about the voltage of the zero line to the live wire, and this voltage is .

[0096] In the exemplary embodiments of the present application, when the motor withstand voltage is poor, it is equivalent to that there is a large resistance between the shell and the coil, since there is a potential difference between GND and SGND, the current flows into the detection circuit through the shell, causing there to be a square wave signal with a frequency of 50HZ and a duty cycle less than 50% at Z even when the microswitch is opened.

[0097] In the exemplary embodiments of the present application, the current flow direction is as shown in Figure 8 .

[0098] Embodiment Seven

[0099] This embodiment is based on any of the above embodiments, and gives an embodiment scheme in which the threshold value is set by voltage adjustment.

[0100] In the exemplary embodiments of the present application, the method can further comprise: adjusting the size of the set threshold value according to the working voltage of the food processor.

[0101] In the exemplary embodiment of the present application, the working voltage U of the current food processor, such as a soybean milk machine, uses a range of 155-275V, and the conduction voltage of the triode is 0.7v, and it can be calculated that When the triode starts to conduct, the time t is inversely proportional to the current working voltage U, and the greater the voltage U, the faster the conduction. Therefore, the threshold value is adjusted according to the current working voltage U, that is, the low level and the duration is greater than (0.01-2T*220 / U)S, or the high level and the duration is less than (0.01+2T*220 / U)S, and it is considered that the detection signal is normal, otherwise it is confirmed that the detection abnormality caused by poor voltage resistance.

[0102] In the exemplary embodiment of the present application, through the embodiment scheme, the interference of the pulse width difference at different working voltages is avoided, and the accuracy of high and low voltage judgment is increased.

[0103] Embodiment eight

[0104] The embodiment is based on any of the above embodiments, and an embodiment scheme for expanding the difference between the detection signals of poor voltage resistance and normal is given by setting appropriate resistance values.

[0105] In the exemplary embodiment of the present application, R4 (or R8) = 5.1KΩ, R1=R2=R3=73.3KΩ (or R5=R6=R7=73.3KΩ) can be selected in the embodiment scheme. Since the power of the resistor is generally 1 / 4W, in order to ensure that the resistor will not be burned out due to excessive power, that is, U*U / R<0.25, considering the common specifications of the resistor, the embodiment scheme adopts the mode of three 73.3 ohm resistors in series, thereby reducing the power consumption of each resistor. At this time, the maximum power consumption of each resistor is 275*275*0.45*0.45 / 220K / 3=0.023W, which meets the use requirements.

[0106] In the exemplary embodiment of the present application, when the motor is normal, the conduction condition of the triode is Since the time length between the two zero points when the normal mains voltage crosses zero is 10ms, in order to ensure that the detection signal (such as the zero-crossing signal) at Z is consistent with the mains zero-crossing as much as possible, that is, the smaller the conduction time t, the current conduction time t<0.5ms can meet the use requirements, and at this time it can be calculated that R4 needs to be greater than 4.4KΩ.

[0107] In the exemplary embodiment of the present application, when the motor has poor voltage resistance, the resistance of R is in the order of megohm, and at this time the conduction condition of the triode is From the formula, the greater R is, the greater the starting conduction time t is; the greater R4 is, the greater the starting conduction time t is. Therefore, the greater R4 is, the more accurate the zero-crossing of the motor in normal state is, but the smaller the difference with the motor in poor voltage endurance state is; and the smaller R4 is, the greater the zero-crossing offset of the motor in normal state is, but the greater the difference with the motor in poor voltage endurance state is.

[0108] In the exemplary embodiment of the present application, the embodiment scheme sets R4=5.1K, and from the calculation, the starting conduction time t of the motor in normal state is 0.31ms, that is, the pulse width of the low level of the zero-crossing signal at this time is (0.01-2t)S=9.4ms, and the pulse width of the high level is 10.6ms. When the motor is in poor voltage endurance state, assuming that R is 1MΩ, the conduction time t is 2.6ms, that is, the pulse width of the low level of the zero-crossing signal at this time is (0.01-2t)S=4.8ms, and the pulse width of the high level is 15.2ms. The pulse widths have a difference of 4.6ms, which is relatively large, and can be effectively detected.

[0109] In the exemplary embodiment of the present application, through the embodiment scheme, the difference of the pulse widths in normal zero-crossing and poor voltage endurance state is increased, so that the detection is more reliable.

[0110] Those of ordinary skill in the art will realize and understand that all or some of the steps in the methods disclosed above and the functional modules / units in the systems and devices can be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component can have multiple functions, or one function or step can be performed by several physical components in cooperation. Some or all of the components can be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on computer-readable media, which can include computer storage media (or non-transitory media) and communication media (or transitory media). As is well known to those of ordinary skill in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by a computer. Furthermore, it is common and well understood by those of ordinary skill in the art that communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and can include any information delivery media.

Claims

1. A method of motor monitoring for a food processor, characterized by, The food processor comprises a master control circuit and a power supply, a switch, a detection circuit and a motor driving circuit connected in sequence; a detection signal output end of the detection circuit is connected with a signal input end of the master control circuit; a first end of the switch is connected with a zero line of the power supply, and a second end is connected with a detection signal input end of the detection circuit; the method comprises: The switch comprises a closed state and an open state; When the switch is in the open state, the motor is in a non-working state, and a voltage value of a signal input end through a motor shell is obtained, which can determine whether the motor has a poor voltage resistance; When the voltage value is zero, it is determined that the motor does not have a poor voltage resistance; When the voltage value is greater than zero and less than a preset voltage threshold, it is determined that the motor has a poor voltage resistance.

2. The motor monitoring method of claim 1, wherein, The method further comprises controlling the closing and opening of the switch through the opening and closing of a cup cover of the food processor.

3. The motor monitoring method of claim 2, wherein, The switch is a magnetic control micro switch.

4. The motor monitoring method of claim 1, wherein, The detection circuit comprises a diode, a first voltage dividing resistor, a second voltage dividing resistor, a third voltage dividing resistor, a fourth voltage dividing resistor, a triode, a first filter capacitor, a second filter capacitor and a pull-up resistor.

5. The motor monitoring method of claim 4, wherein, The diode, the first voltage dividing resistor, the second voltage dividing resistor, the third voltage dividing resistor and the fourth voltage dividing resistor are connected in sequence; an anode of the diode is a detection signal input end of the detection circuit, a first end of the fourth voltage dividing resistor is connected with the third voltage dividing resistor, and a second end is connected with a signal ground SGND; The first filter capacitor is connected in parallel with the fourth voltage dividing resistor; An emitter of the triode is connected with the first end of the fourth voltage dividing resistor, a base is connected with the SGND, and a collector is connected with a first end of the pull-up resistor; A second end of the pull-up resistor is connected with a power supply; the second filter capacitor is connected in parallel between the base and the collector of the triode; A signal input end of the master control circuit is connected with the collector.

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