Motor protection circuit and ventilation equipment

Abstract

The utility model discloses a motor protection circuit and ventilation equipment, which are characterized in that a first power supply input end is connected with a normally open contact of a first relay and a first end of a coil, a second power supply input end is connected with a normally closed contact of the first relay, and a third power supply input end is connected with a second end of the coil; therefore, when the first power supply input end, the second power supply input end and the third power supply input end receive abnormal power supply input signals, the first optocoupler, the second optocoupler, the first triode, the second triode, the third triode or the fourth triode can be controlled to be switched on and off through the relay. According to the invention, damage to the motor caused by wrong connection of the power supply can be avoided, the operation safety of the motor is improved, and the service life of the motor is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor field especially is related to a motor protection circuit and ventilation equipment. BACKGROUND

[0002] The motor usually includes at least three wiring terminals such as high-grade wiring terminal, low-grade wiring terminal and common wiring terminal, and the user connects the wiring according to the color of the wiring terminal and the instruction manual when wiring the motor.

[0003] However, the above-mentioned method is easy to connect the wrong line, which can easily cause the motor to be damaged. UTILITY MODEL CONTENTS

[0004] The utility model aims at overcoming the defects and deficiencies of prior art, and provides a motor protection circuit and ventilation equipment, which can avoid the damage of the motor caused by the wrong connection of the line and improve the operation reliability and service life of the motor.

[0005] In a first aspect, the utility model provides a motor protection circuit, which comprises a first power input end, a second power input end, a third power input end, a first relay, a second relay, a third relay, a first optocoupler, a second optocoupler, a first triode, a second triode, a third triode and a fourth triode.

[0006] The first power input end is connected with the normally open contact of the first relay, the first end of the first relay coil and the first end of the first optocoupler respectively.

[0007] The second power input end is connected with the normally closed contact of the first relay and the first end of the second optocoupler respectively.

[0008] The third power input end is connected with the second end of the first relay coil, the second end of the first optocoupler and the second end of the second optocoupler respectively.

[0009] The third end of the first optocoupler is connected with the base of the first triode, the collector of the third triode and the base of the fourth triode respectively, the collector of the first triode is connected with the second end of the coil of the second relay, the emitter of the third triode is grounded, the first end of the coil of the second relay is connected with the power supply, the normally open contact of the second relay is connected with the common contact of the first relay, the normally closed contact of the second relay is connected with the first driving circuit of the motor, and the fourth end of the first optocoupler is connected with the power supply.

[0010] The third end of the second optocoupler is connected with the base of the second triode, the base of the third triode and the collector of the fourth triode respectively, the collector of the second triode is connected with the second end of the coil of the third relay, the emitter of the second triode is grounded, the first end of the third relay is connected with the power supply, the normally open contact of the third relay is connected with the common contact of the first relay, the normally closed contact of the third relay is connected with the second driving circuit of the motor, and the fourth end of the second optocoupler is connected with the power supply.

[0011] In a second aspect, the utility model provides a ventilation equipment, including motor and the motor protection circuit as any above.

[0012] In the embodiment of the application, the first power input end is connected with the normally open contact of the first relay and the first end of the coil, the second power input end is connected with the normally closed contact of the first relay, and the third power input end is connected with the second end of the coil, so that when the first power input end, the second power input end and the third power input end receive abnormal power input signals, the first optocoupler, the second optocoupler, the first triode, the second triode, the third triode or the fourth triode can be controlled by using the relay, and then the driving circuit of the motor can be controlled by the second relay and the third relay, the operation of the motor is controlled, the motor can be prevented from being damaged due to the wrong connection of the power supply, and the operation safety and the service life of the motor are improved.

[0013] In order to better understand and implement, the utility model is described in detail below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the circuit diagram of the motor protection circuit in an embodiment of the utility model;

[0015] Figure 2 It is the circuit diagram of the motor protection circuit in another embodiment of the utility model;

[0016] Figure 3 It is the circuit diagram of the voltage conversion module in an embodiment of the utility model;

[0017] Figure 4 It is the structural schematic diagram of the ventilation equipment in an embodiment of the utility model. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantage of the application more clear, the utility model mode will be further described in detail below with reference to the drawings.

[0019] It should be clear that the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0020] The terms used in 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 present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein means and includes any or all possible combinations of one or more associated listed items.

[0021] The following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all the embodiments consistent with the present application. Instead, they are only examples of ventilation equipment and methods consistent with some aspects of the present application as detailed in the appended claims. In the description of the present application, it should be understood that the terms "first", "second", "third" and the like are only used to distinguish similar objects, and do not necessarily describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0022] In addition, in the description of the present application, unless otherwise stated, "several" means two or more. "And / or" describes the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents a "or" relationship between the associated objects before and after.

[0023] As Figure 1 The present application provides a motor protection circuit, comprising: comprising a first power input terminal H, a second power input terminal L, a third power input terminal COM, a first relay KY3, a second relay KY1, a third relay KY2, a first optocoupler U1, a second optocoupler U2, a first triode Q1, a second triode Q2, a third triode Q3 and a fourth triode Q4;

[0024] The first power input terminal H is connected with the normally open contact of the first relay KY3, the first end of the first relay KY3 coil and the first end of the first optocoupler U1, respectively;

[0025] The second power input end L is connected with the normally closed contact of the first relay KY3 and the first end of the second optocoupler U2 respectively.

[0026] The third power input end COM is connected with the second end of the coil of the first relay KY3, the second end of the first optocoupler U1 and the second end of the second optocoupler U2 respectively.

[0027] The third end of the first optocoupler U1 is connected with the base of the first triode Q1, the collector of the third triode Q3 and the base of the fourth triode Q4 respectively, the collector of the first triode Q1 is connected with the second end of the coil of the second relay KY1, the emitter of the third triode Q3 is grounded, the first end of the coil of the second relay KY1 is connected with the power supply, the normally open contact of the second relay KY1 is connected with the common contact 220V_LOM of the first relay KY3, the normally closed contact of the second relay KY1 is connected with the first driving circuit of the motor, and the fourth end of the first optocoupler U1 is connected with the power supply.

[0028] The third end of the second optocoupler U2 is connected with the base of the second triode Q2, the base of the third triode Q3 and the collector of the fourth triode Q4 respectively, the collector of the second triode Q2 is connected with the second end of the coil of the third relay KY2, the emitter of the second triode Q2 is grounded, the first end of the coil of the third relay KY2 is connected with the power supply, the normally open contact of the third relay KY2 is connected with the common contact 220V_LOM of the first relay KY3, the normally closed contact of the third relay KY2 is connected with the second driving circuit of the motor, and the fourth end of the second optocoupler U2 is connected with the power supply.

[0029] The first power input end H and the second power input end L can be used to be connected with 220V live wire, the third power input end COM can be used to be connected with 220V neutral wire, and usually only one end of the first power input end H and the second power input end L has 220V input.

[0030] The first optocoupler U1 and the second optocoupler U2 are used to electrically isolate the input power signal, so as to ensure the safety of the subsequent triodes, relays and other components.

[0031] The first driving circuit is used to drive the motor to run at a first rotating speed, and the second driving circuit is used to drive the motor to run at a second rotating speed. The first rotating speed can be greater than the second rotating speed.

[0032] The first driving circuit and the second driving circuit can be common motor driving circuits.

[0033] The wiring protection principle of the motor protection circuit of the embodiment of the application is described below. In the embodiment of the application, the first driving circuit is used to drive the motor to run at a high speed, and the second driving circuit is used to drive the motor to run at a low speed.

[0034] When the first power input end H inputs the mains 220V_L, the second power input end L does not input, and the third power input end COM inputs the mains 220V_N, the first relay KY3 is attracted, the first optocoupler U1 is turned on, the second optocoupler U2 is not turned on, the third transistor Q3 is not turned on because the base electrode cannot be electrified due to the second optocoupler U2 not being turned on, the first transistor Q1 is electrified due to the optocoupler U1 being turned on, the first transistor Q1 is turned on, the second relay KY1 is driven to be attracted, and the first power input end H (the mains 220V control firewire) is connected with 220V_LCOM, and the motor is operated at a high gear.

[0035] When the second power input end L inputs the mains 220V_L, the first power input end H does not input, and the third power input end COM inputs the mains 220V_N, the first relay KY3 is not attracted, the second optocoupler U2 is turned on, the third transistor Q3 and the fourth transistor Q4 are not turned on because the collector electrode and the base electrode cannot be electrified due to the first optocoupler U1 not being turned on, the second transistor Q2 is electrified due to the second optocoupler U2 being turned on, the second transistor Q2 is turned on, the third relay KY2 is driven to be attracted, the second power input end L (the mains 220V control firewire) is connected with 220V_LCOM, and the motor is operated at a low gear.

[0036] When the first power input end H and the second power input end L are both powered off, the circuit has no power input, and stops working.

[0037] When the second power input end L and the first power input end H simultaneously input the mains 220V_L, and the third power input end COM inputs the mains 220V_N, the first relay KY3 is attracted, the first optocoupler U1 and the second optocoupler U2 are both turned on, the base electrode and the collector electrode of the third transistor Q3 and the fourth transistor Q4 are both electrified due to the first optocoupler U1 and the second optocoupler U2 being turned on, the third transistor Q3 and the fourth transistor Q4 are turned on, the base electrode voltage of the first transistor Q1 and the second transistor Q2 is clamped to Uce saturation voltage drop under the action of the collector electrode saturation voltage drop Uce of the third transistor Q3 and the fourth transistor Q4, and the voltage is lower than the turn-on voltage Vbe of the transistor, so the first transistor Q1 and the second transistor Q2 are not turned on, the second relay KY1 and the third relay KY2 are not attracted, the motor cannot be normally electrified, and thus the motor does not operate, so that the high and low gears of the motor cannot be simultaneously connected to the power supply, and the motor is prevented from being damaged.

[0038] When the first power input end H is connected to the city power 220V_L, the second power input end L is connected to the city power 220V_N, and the third power input end COM is connected to the city power 220V_L, the first relay KY3 is not attracted, because the first power input end H and the third power input end COM are both connected to the city power 220V_L, so the first optocoupler U1 is not turned on, while the second power input end L is connected to the city power 220V_N and the third power input end COM is connected to the city power 220V_L, so the second optocoupler U2 is turned on, because the first optocoupler U1 is not turned on, so the third transistor Q3 collector and the fourth transistor Q4 base are not powered and thus are not turned on, the second transistor Q2 base is powered due to the second optocoupler U2 being turned on, the second transistor Q2 is turned on, the third relay KY2 is driven to be attracted, and the motor runs at low speed.

[0039] When the first power input end H is connected to the city power 220V_N, the second power input end L is connected to the city power 220V_L, and the third power input end COM is connected to the city power 220V_N, the first relay KY3 is not attracted, because the first power input end H and the third power input end COM are both connected to the city power 220V_N, so the first optocoupler U1 is not turned on, while the second power input end L is connected to the city power 220V_L and the third power input end COM is connected to the city power 220V_N, so the second optocoupler U2 is turned on, because the first optocoupler U1 is not turned on, so the third transistor Q3 collector and the fourth transistor Q4 base are not powered and thus are not turned on, the second transistor Q2 base is powered due to the second optocoupler U2 being turned on, the second transistor Q2 is turned on, the third relay KY2 is driven to be attracted, and the motor runs at low speed.

[0040] Please refer to Table 1, which is a schematic table of the running state of the motor when the first power input end, the second power input end, and the third power input end are connected to the neutral line (N), the live line (L), or not connected to the power in an embodiment of the application.

[0041]

[0042] In this embodiment, when the first power input end, the second power input end, and the third power input end are connected to different power sources, the motor can be protected and will not be damaged due to wiring errors.

[0043] In this embodiment, by connecting the first power input terminal to the normally open contact of the first relay and the first end of the coil, connecting the second power input terminal to the normally closed contact of the first relay, and connecting the third power input terminal to the second end of the coil, when abnormal power input signals are received at the first, second, and third power input terminals, the relays can be used to control the switching of the first optocoupler, the second optocoupler, the first transistor, the second transistor, the third transistor, or the fourth transistor. This allows the second and third relays to control the motor's drive circuit, thereby controlling the motor's operation. This application avoids damage to the motor due to incorrect power connection, improving the motor's operational safety and lifespan.

[0044] In one embodiment, the motor protection circuit may further include a first thermistor, the first end of which is connected to the first power input terminal, and the second end of which is connected to the normally open contact of the first relay, the first end of the first relay coil, and the first end of the first optocoupler.

[0045] The first thermistor is a sensor resistor whose resistance changes with temperature. The first thermistor can control the current in the circuit based on changes in ambient temperature. In this embodiment, the first thermistor can be a positive temperature coefficient thermistor.

[0046] In this embodiment, by connecting a thermistor in series at the first power input terminal, the current in the circuit is reduced when the ambient temperature rises, thereby preventing damage to the relay caused by excessive temperature.

[0047] like Figure 2 As shown, in one embodiment, the motor protection circuit may further include a first diode D2, a second diode D4, a first resistor R5, a second resistor R6, a third resistor R7, and a fourth resistor R8;

[0048] The anode of the first diode D2 is connected to the normally open contact of the first relay KY3 and the first end of the coil of the first relay KY3, respectively. The cathode of the first diode D2 is connected to the first end of the first resistor R5 and the first end of the first optocoupler U1, respectively. The second end of the first resistor R5 is connected to the third power input terminal COM, the second end of the first optocoupler U1 and the second end of the third resistor R7, respectively. The first end of the third resistor R7 is connected to the third power input terminal COM.

[0049] An anode of the second diode D4 is connected with a normally closed contact of the first relay KY3 and the second power input end L respectively, a cathode of the second diode D4 is connected with a first end of a second resistor R6 and a first end of a second optocoupler U2 respectively, a second end of the second resistor R6 is connected with a third power input end COM, a second end of the second optocoupler U2 and a second end of a fourth resistor R8 respectively, a first end of the fourth resistor R8 is connected with the third power input end COM.

[0050] In the embodiment, the parallel resistor at the input end of the optocoupler can prevent the false transmission of signals caused by the false operation of the optocoupler, and the series connection of the diode and the resistor at the input end of the optocoupler can limit the current input to the optocoupler by the resistor, and ensure the unidirectional input of the power signal by the diode, thereby improving the safety and service life of the optocoupler.

[0051] As shown in FIG. 1, the motor protection circuit includes a first optocoupler U1, a second optocoupler U2, a first relay KY3, a second relay KY4, a first triode Q1, a second triode Q2, a third triode Q3, a fourth triode Q4, a first capacitor E4, a second capacitor E5, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a first power input end L, a second power input end COM, a third power input end COM1, a fourth power input end COM2, a first thermal resistor RT1, a second thermal resistor RT2, a third thermal resistor RT3, a first power supply and a second power supply. Figure 2 As shown in FIG. 1, in one embodiment, the motor protection circuit further includes a first capacitor E4 and a second capacitor E5.

[0052] A first end of the first capacitor E4 is connected with a third end of the first optocoupler U1, and a second end of the first capacitor E4 is grounded; the second capacitor E5 is connected with a third end of the second optocoupler U2, and a second end of the second capacitor E5 is grounded.

[0053] The first capacitor E4 and the second capacitor E5 can be electrolytic capacitors.

[0054] In the embodiment, the first capacitor E4 and the second capacitor E5 are used to filter the signals output by the optocouplers, thereby avoiding the false operation of the triodes and improving the accuracy of the motor control.

[0055] Optionally, the motor protection circuit can further include resistors R3-R4, R9-R12. The resistor R3 is arranged between the power supply and a fourth end of the first optocoupler U1, the resistor R9 is arranged between a third end of the first optocoupler U1 and a base of the first triode Q1, the resistor R10 is arranged between a third end of the second optocoupler U2 and a base of the third triode Q3, the resistor R11 is arranged between the third end of the first optocoupler U1 and a base of the fourth triode Q4, and the resistor R4 is arranged between the power supply and the first optocoupler U2.

[0056] The resistors R3-R4, R9-R12 are used to limit the current input to the bases of the triodes, thereby avoiding the damage of the triodes caused by excessive current and improving the safety of the operation of the triodes.

[0057] In one embodiment, the motor protection circuit further includes a third thermal resistor RT3; a first end of the third thermal resistor RT3 is connected with the third power input end, and a second end of the third thermal resistor RT3 is connected with a common end of the motor.

[0058] The high temperature protection of the motor can be realized by the thermistor, and the operation safety and service life of the motor are improved.

[0059] In one embodiment, a voltage conversion module for converting the power supply voltage into a target voltage is further included; a first input terminal of the voltage conversion module is connected with the common contact of the first relay, and a second input terminal of the voltage conversion module is connected with the third power supply input terminal.

[0060] The voltage conversion module can convert the voltage of the power supply into the target voltage by using the existing voltage conversion circuit. The target voltage can be determined according to the voltage used by each circuit module of the motor protection circuit, and in the embodiment of the application, the target voltage can be a direct current voltage. The voltage conversion module can convert the target voltage by using the existing AC-DC circuit and voltage conversion circuit.

[0061] When the first power supply input terminal H inputs the commercial power 220V_L, the second power supply input terminal L is not input, and the third power supply input terminal COM inputs the commercial power 220V_N, the first relay KY3 is attracted, the first input terminal of the voltage conversion module inputs the commercial power 220V_L through the normally open contact of the first relay KY3, the second input terminal of the voltage conversion module inputs the commercial power 220V_N, and the voltage conversion module works normally to convert the power supply voltage into the target voltage VCC, thereby supplying power to each circuit module of the motor protection circuit.

[0062] When the second power supply input terminal L inputs the commercial power 220V_L, the first power supply input terminal H is not input, and the third power supply input terminal COM inputs the commercial power 220V_N, the first relay KY3 is not attracted, the first input terminal of the voltage conversion module inputs the commercial power 220V_L through the normally closed contact of the first relay KY3, the second input terminal of the voltage conversion module inputs the commercial power 220V_N, and the voltage conversion module works normally to convert the power supply voltage into the target voltage VCC, thereby supplying power to each circuit module of the motor protection circuit.

[0063] When the first power supply input terminal H and the second power supply input terminal L are both powered off, the voltage conversion module has no power supply signal input, the motor protection circuit is powered off, and the motor stops running.

[0064] When the second power supply input terminal L and the first power supply input terminal H simultaneously input the commercial power 220V_L, and the third power supply input terminal COM inputs the commercial power 220V_N, the first relay KY3 is attracted, the first input terminal of the voltage conversion module inputs the commercial power 220V_L through the normally open contact of the first relay KY3, the second input terminal of the voltage conversion module inputs the commercial power 220V_N, and the voltage conversion module works normally to convert the power supply voltage into the target voltage VCC, thereby supplying power to each circuit module of the motor protection circuit.

[0065] When the first power input end H is connected to the commercial power 220V_L, the second power input end L is connected to the commercial power 220V_N, and the third power input end COM is connected to the commercial power 220V_L, the first relay KY3 is not attracted, the first input end of the voltage conversion module inputs the commercial power 220V_N through the normally closed contact of the first relay KY3, the second input end of the voltage conversion module inputs the commercial power 220V_N through the second power input end L, and the voltage conversion module works normally to convert the power supply voltage into the target voltage VCC, thereby supplying power to each circuit module of the motor protection circuit.

[0066] When the first power input end H is connected to the commercial power 220V_N, the second power input end L is connected to the commercial power 220V_L, and the third power input end COM is connected to the commercial power 220V_N, the first relay KY3 is not attracted, the first input end of the voltage conversion module inputs the commercial power 220V_L through the normally closed contact of the first relay KY3, the second input end of the voltage conversion module inputs the commercial power 220V_N, and the voltage conversion module works normally to convert the power supply voltage into the target voltage VCC, thereby supplying power to each circuit module of the motor protection circuit.

[0067] As shown in Figure 3 The voltage conversion module includes a rectifier bridge DB1, a voltage conversion chip U3, a sampling resistor RS1, an inductor L2, a voltage stabilizing tube DZ1, and a third diode D2.

[0068] The first end of the rectifier bridge DB1 is connected to the common contact of the first relay, the second end of the rectifier bridge DB1 is connected to the third power input end COM, the third end of the rectifier bridge DB1 is connected to the drain end of the voltage conversion chip U3, the fourth end of the rectifier bridge DB1 is grounded, the sampling end of the voltage conversion chip U3 is connected to the first end of the inductor L2 through the sampling resistor RS1, and the second end of the inductor L2 is connected to the anode of the third diode D2; the power supply end of the voltage conversion chip U3 is connected to the anode of the voltage stabilizing tube, and the cathode of the voltage stabilizing tube DZ1 is connected to the cathode of the third diode D2.

[0069] The voltage conversion chip U3 can be a step-down circuit.

[0070] The 220V alternating current is rectified into a high-voltage direct current 310V by the rectifier bridge DB1, and is converted into a low-voltage direct current to supply power to other elements on the motor protection circuit by the step-down circuit. The input voltage range of the voltage conversion module of the embodiment is wide (85V-265V), which is suitable for power grids with large voltage fluctuations and has a relatively low cost compared to an isolated power supply.

[0071] Optionally, the voltage conversion module can further include a filtering module, the filtering module including capacitors C1-C2, electrolytic capacitors E1-E3, an inductor L1 and a resistor R2, the positive pole of the electrolytic capacitor E1 being connected with the third end of the rectifier bridge DB1, the first end of the inductor L1 and the first end of the resistor R2 respectively, the second end of the inductor L1 being connected with the drain end of the voltage conversion chip U3, the second end of the resistor R2 and the positive pole of the electrolytic capacitor E2 respectively, the negative poles of the electrolytic capacitors E1-E2 being grounded; the first end of the capacitor C1 being connected with the second end of the sampling resistor RS1, the second end of the capacitor C1 being connected with the power supply end of the voltage conversion chip U3, the positive pole of the electrolytic capacitor E3 and the first end of the capacitor C2 being connected with the anode of the third diode D2, the negative pole of the electrolytic capacitor E3 and the second end of the capacitor C2 being grounded.

[0072] By using the capacitors, the electrolytic capacitors and the inductor and the resistor to form the filtering module, the power supply signal of the voltage conversion module is filtered, and the reliability of the output power supply signal is improved.

[0073] In one embodiment, a fuse F1, a voltage-dependent resistor ZNR, a second thermistor RT1 and an X capacitor XC1 are further included.

[0074] The first end of the fuse F1 is connected with the common contact of the first relay, the second end of the fuse F1 is connected with the first end of the voltage-dependent resistor ZNR, the first end of the second thermistor RT1 and the first end of the X capacitor XC1 respectively, the second end of the voltage-dependent resistor ZNR and the second end of the second thermistor RT1 are connected with the third power supply input end COM, and the second end of the X capacitor XC1 is connected with the first end of the rectifier bridge DB1.

[0075] After the 220V alternating current power supply passes through the short-circuit fuse F1, and then passes through the lightning surge protection voltage-dependent resistor ZNR1 and the second thermistor RT1 for protection processing, the 220V alternating current power supply is input into the rectifier bridge DB1 for rectification. By using the fuse F1, the voltage-dependent resistor ZNR1 and the second thermistor RT1, short-circuit protection, temperature protection and under-voltage protection for the input power supply are realized, and the power supply reliability is improved.

[0076] As shown in Figure 4 The application further provides a ventilation device 100, which includes the motor protection circuit 110 and the motor 120 according to any one of the above.

[0077] The motor 120 can be a single-phase two-gear speed-regulating motor.

[0078] In one embodiment, the ventilation device can include a fresh air machine, a wind curtain machine, a fan or a wind cabinet.

[0079] The utility model is not limited to the above embodiment, if the various modifications or deformation of the utility model do not deviate from the spirit and scope of the utility model, if these modifications and deformation belong to the right claim and equivalent technical scope of the utility model, then the utility model also intends to contain these modifications and deformation.

Claims

1. A motor protection circuit, characterized by: The first power input end, the second power input end, the third power input end, the first relay, the second relay, the third relay, the first optocoupler, the second optocoupler, the first triode, the second triode, the third triode and the fourth triode are connected to each other. The first power input end is connected to the normally open contact of the first relay, the first end of the first relay coil and the first end of the first optocoupler. The second power input end is connected to the normally closed contact of the first relay and the first end of the second optocoupler. The third power input end is connected to the second end of the first relay coil, the second end of the first optocoupler and the second end of the second optocoupler. The third end of the first optocoupler is connected to the base of the first triode, the collector of the third triode and the base of the fourth triode, the collector of the first triode is connected to the second end of the coil of the second relay, the emitter of the third triode is grounded, the first end of the coil of the second relay is connected to the power supply, the normally open contact of the second relay is connected to the common contact of the first relay, the normally closed contact of the second relay is connected to the first driving circuit of the motor, and the fourth end of the first optocoupler is connected to the power supply. The third end of the second optocoupler is connected to the base of the second triode, the base of the third triode and the collector of the fourth triode, the collector of the second triode is connected to the second end of the coil of the third relay, the emitter of the second triode is grounded, the first end of the coil of the third relay is connected to the power supply, the normally open contact of the third relay is connected to the common contact of the first relay, the normally closed contact of the third relay is connected to the second driving circuit of the motor, and the fourth end of the second optocoupler is connected to the power supply.

2. The motor protection circuit of claim 1, wherein: The first end of the first thermistor is connected to the first power input end, and the second end of the first thermistor is connected to the normally open contact of the first relay, the first end of the first relay coil and the first end of the first optocoupler.

3. The motor protection circuit of claim 1, wherein, The first diode, the second diode, the first resistor, the second resistor, the third resistor and the fourth resistor are further included. The anode of the first diode is connected to the normally open contact of the first relay and the first end of the first relay coil, the cathode of the first diode is connected to the first end of the first resistor and the first end of the first optocoupler, the second end of the first resistor is connected to the third power input end, the second end of the first optocoupler and the second end of the third resistor, and the first end of the third resistor is connected to the third power input end. The anode of the second diode is connected to the normally closed contact of the first relay and the second power input end, the cathode of the second diode is connected to the first end of the second resistor and the first end of the second optocoupler, the second end of the second resistor is connected to the third power input end, the second end of the second optocoupler and the second end of the fourth resistor, and the first end of the fourth resistor is connected to the third power input end.

4. The motor protection circuit of claim 1, wherein: The first capacitor and the second capacitor are further included. The first end of the first capacitor is connected with the third end of the first photocoupler, and the second end of the first capacitor is grounded; the second capacitor is connected with the third end of the second photocoupler, and the second end of the second capacitor is grounded.

5. The motor protection circuit of claim 1, wherein: The voltage conversion module for converting the power supply voltage into a target voltage is further included; the first input end of the voltage conversion module is connected with the common contact of the first relay, and the second input end of the voltage conversion module is connected with the third power input end.

6. The motor protection circuit of claim 5, wherein: The voltage conversion module includes a rectifier bridge, a voltage conversion chip, a sampling resistor, an inductor, a voltage stabilizing tube and a third diode. The first end of the rectifier bridge is connected with the common contact of the first relay, the second end of the rectifier bridge is connected with the third power input end, the third end of the rectifier bridge is connected with the drain end of the voltage conversion chip, the fourth end of the rectifier bridge is grounded, the sampling end of the voltage conversion chip is connected with the first end of the inductor through the sampling resistor, and the second end of the inductor is connected with the anode of the third diode; the power supply end of the voltage conversion chip is connected with the anode of the voltage stabilizing tube, and the cathode of the voltage stabilizing tube is connected with the cathode of the third diode.

7. The motor protection circuit of claim 6, wherein, The fuse, the pressure-sensitive resistor, the second thermistor and the X capacitor are further included. The first end of the fuse is connected with the common contact of the first relay, the second end of the fuse is respectively connected with the first end of the pressure-sensitive resistor, the first end of the second thermistor and the first end of the X capacitor, the second end of the pressure-sensitive resistor and the second end of the second thermistor are connected with the third power input end, and the second end of the X capacitor is connected with the first end of the rectifier bridge.

8. The motor protection circuit of claim 1, wherein: The third thermistor is further included; the first end of the third thermistor is connected with the third power input end, and the second end of the third thermistor is connected with the common end of the motor.

9. A ventilation device, characterized in that The motor and the motor protection circuit according to any one of claims 1-8 are included.

10. The ventilation device according to claim 9, characterized in that The ventilation equipment includes a fresh air machine, a wind curtain machine, a fan or a wind cabinet.

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