Switching circuit driven by motor

Abstract

The utility model relates to a switching circuit driven by a motor. The switching circuit comprises a first driving circuit, a relay circuit, a second driving circuit and a silicon controlled switching circuit; wherein the first driving circuit is respectively connected with the relay circuit and the controller, and the relay circuit is respectively connected with an operation interface of the motor and the silicon controlled switch circuit; the second drive circuit is connected with the silicon-controlled switch circuit and the controller. The silicon-controlled switch circuit is connected with an operation interface of the motor. The first driving circuit is used for receiving the PWM wave signal sent by the controller, is in a conducting state and supplies power to the relay circuit; the relay circuit is used for being switched on when the first driving circuit is switched on to drive the motor to operate; the second driving circuit is used for receiving the PWM wave signal sent by the controller, is in a conducting state and supplies power to the silicon-controlled switching circuit; and the silicon controlled rectifier switch circuit is used for conducting the silicon controlled rectifier when the second driving circuit is conducted to drive the motor to operate. The motor can be switched on and off in a zero-spark mode.

Description

TECHNICAL FIELD

[0001] The utility model relates to domestic appliance technical field, in particular to a switching circuit of motor drive. BACKGROUND

[0002] At present, the safety of motor drive of modern domestic range hood influences the safe use of range hood and the personal safety of user. In the prior art, the motor drive circuit of the motor of domestic appliance adopts single relay control circuit, and the single relay control circuit realizes the switching of load. However, the single relay control circuit can produce spark due to the excessive current in switching moment, leading to the shortening of service life of relay. SUMMARY

[0003] Therefore, it is necessary to provide a switching circuit of motor drive aiming at the above technical problems.

[0004] In a first aspect, a switching circuit of motor drive is provided, which comprises a first drive circuit, a relay circuit, a second drive circuit and a silicon controlled switch circuit, wherein,

[0005] The first drive circuit is connected with the relay circuit and a controller respectively, and the relay circuit is connected with the running interface of motor and the silicon controlled switch circuit respectively;

[0006] The second drive circuit is connected with the silicon controlled switch circuit and the controller respectively, and the silicon controlled switch circuit is connected with the running interface of motor;

[0007] The first drive circuit is used for receiving the PWM wave signal sent by the controller, and is in a conducting state to supply power to the relay circuit;

[0008] The relay circuit is used for being turned on when the first drive circuit is in a conducting state, and is used for driving the motor to run;

[0009] The second drive circuit is used for receiving the PWM wave signal sent by the controller, and is in a conducting state to supply power to the silicon controlled switch circuit;

[0010] The silicon controlled switch circuit is used for turning on the silicon controlled switch when the second drive circuit is in a conducting state, and is used for driving the motor to run.

[0011] As an optional implementation, the first drive circuit comprises a first triode, a first resistor, a second resistor, a first electrolytic capacitor, a first diode, a second diode and a first capacitor;

[0012] The collector of the first transistor is connected to the relay circuit, the base of the first transistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the positive electrode of the first electrolytic capacitor and the negative electrode of the first diode respectively, the emitter of the first transistor is connected to the other end of the second resistor, the negative electrode of the first electrolytic capacitor and the positive electrode of the second diode and ground respectively, the positive electrode of the first diode is connected to the negative electrode of the second diode and the negative electrode of the first capacitor respectively, and the positive electrode of the first capacitor is connected to the controller.

[0013] As an optional implementation, the relay circuit comprises a first power supply, a relay and a third diode.

[0014] The ACL fire line of the relay is connected to the running interface of the motor and the thyristor switch circuit, the positive electrode of the relay is connected to the first power supply and the negative electrode of the third diode respectively, and the negative electrode of the relay is connected to the positive electrode of the third diode and the first drive circuit respectively.

[0015] As an optional implementation, the second drive circuit comprises a second transistor, a third resistor, a fourth resistor, a second electrolytic capacitor, a fourth diode, a fifth diode and a second capacitor.

[0016] The collector of the second transistor is connected to the thyristor switch circuit, the base of the second transistor is connected to one end of the third resistor, the other end of the third resistor is connected to one end of the fourth resistor, the positive electrode of the second electrolytic capacitor and the negative electrode of the fourth diode respectively, the emitter of the second transistor is connected to the other end of the fourth resistor, the negative electrode of the second electrolytic capacitor and the positive electrode of the fifth diode and ground respectively, the positive electrode of the fourth diode is connected to the negative electrode of the second capacitor and the negative electrode of the fifth diode respectively, and the positive electrode of the second capacitor is connected to the controller.

[0017] As an optional implementation, the thyristor switch circuit comprises a thyristor, a fifth resistor, a sixth resistor, an optical coupler, a seventh resistor, an eighth resistor, a second power supply, a third capacitor and a fourth capacitor.

[0018] The anode of the thyristor is connected with one end of the fifth resistor and the relay circuit respectively, the cathode of the thyristor is connected with the running interface of the motor and the negative pole of the third capacitor respectively, the other end of the fifth resistor is connected with the positive pole of the third capacitor and one end of the sixth resistor respectively, the other end of the sixth resistor is connected with pin one of the optocoupler, pin two of the optocoupler is connected with one end of the eighth resistor, the positive pole of the fourth capacitor and the control electrode of the thyristor respectively, the other end of the eighth resistor is connected with the negative pole of the fourth capacitor and the ground, the LED cathode of the optocoupler is connected with one end of the seventh resistor, the other end of the seventh resistor is connected with the second power supply, and the LED anode of the optocoupler is connected with the second drive circuit.

[0019] As an optional implementation, when the high-voltage load starts the motor, the controller switches the first drive circuit and the second drive circuit to work alternately through the PWM wave signal.

[0020] As an optional implementation, the thyristor is a low-impedance bidirectional thyristor, and the thyristor can bear the instantaneous current of a preset current threshold.

[0021] As an optional implementation, the duty cycle of the PWM wave signal is 50%.

[0022] The utility model provides a kind of switching circuit of motor drive, and the technical scheme provided by the embodiment of the utility model at least brings following beneficial effects: abandon the IO single level control relay circuit of prior art, using the driving method of PWM wave signal, two kinds of switchable motor drive circuit, plus isolation control thyristor low impedance electronic switch circuit combination, realize zero spark switch, prevent accidental conduction protection, controller control's stabilized voltage output, improve the reliable use of load driving circuit of household appliance class high voltage.Further reduce cost, improve security, to improve the reliable use of motor drive of household appliance. Improve the development efficiency of developer, shorten development cycle, improve product reliability lay great foundation.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the utility model. ACCURACY OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme in the embodiment of the present application or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0025] Figure 1The utility model provides a prior art motor drive's switching circuit's structure schematic diagram for the utility model embodiment provides.

[0026] Figure 2 The utility model provides a motor drive's switching circuit's structure schematic diagram for the utility model embodiment provides. DETAILED DESCRIPTION

[0027] In order to make the utility model's purpose, technical scheme and advantage more clear and obvious, the following is with the figure and embodiment, and the utility model is further detailedly explained.It should be understood that the specific embodiment described here is only used to explain the application, and is not used to limit the utility model.

[0028] Figure 1 The utility model provides a prior art motor drive's switching circuit's structure schematic diagram for the utility model embodiment provides. Figure 1 As shown, single relay control circuit is adopted to realize the switching of load, but the current is too large in the switching moment of motor, and spark is generated, which leads to short service life of relay, and the single IO port control is easy to fail to start due to accidental crash, and safety risk of misoperation is easy to be generated.

[0029] Figure 2 The utility model provides a motor drive's switching circuit's structure schematic diagram for the utility model embodiment provides. Figure 2 As shown, the switching circuit includes first drive circuit 201, relay circuit 202, second drive circuit 203 and thyristor switch circuit 204.

[0030] First drive circuit 201 is connected with relay circuit 202 and controller respectively, and relay circuit 202 is connected with the running interface of motor and thyristor switch circuit 204 respectively.

[0031] Second drive circuit 203 is connected with thyristor switch circuit 204 and controller respectively, and thyristor switch circuit 204 is connected with the running interface of motor.

[0032] First drive circuit 201 is used to receive the PWM wave signal sent by controller, and is in the on state, and supplies power for relay circuit 202.

[0033] Relay circuit 202 is used to be connected when first drive circuit 201 is on, and drives motor to run.

[0034] Second drive circuit 203 is used to receive the PWM wave signal sent by controller, and is in the on state, and supplies power for thyristor switch circuit 204.

[0035] Thyristor switch circuit 204 is used to turn on the thyristor when second drive circuit 203 is on, and drives motor to run.

[0036] As an optional embodiment, the first driving circuit 201 comprises a first triode Q1, a first resistor R1, a second resistor R2, a first electrolytic capacitor C11, a first diode D1, a second diode D2 and a first capacitor C21.

[0037] The collector of the first triode Q1 is connected to the relay circuit 202, one end of the base of the first triode Q1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, the positive pole of the first electrolytic capacitor C11 and the negative pole of the first diode D1 respectively, the emitter of the first triode Q1 is connected to the other end of the second resistor R2, the negative pole of the first electrolytic capacitor C11 and the positive pole of the second diode D2 and grounded respectively, the positive pole of the first diode D1 is connected to the negative pole of the second diode D2 and the negative pole of the first capacitor C21 respectively, and the positive pole of the first capacitor C21 is connected to the controller.

[0038] In this way, when the PWM wave signal sent by the controller to the first driving circuit 201 is high, the current charges the first electrolytic capacitor C11 through the first capacitor C21 and the first diode D1 until the level is stable. The current flows through the be junction of the first triode Q1 through the first resistor R1, the current is Ib_Q1, and the first triode Q1 is saturated and turned on. After the voltage of the first capacitor C21 is full, there is no current through the first diode D1. When the PWM wave signal sent by the controller to the first driving circuit 201 is low, the first capacitor C21 is discharged through the second diode D2 and the first capacitor C21, and the first electrolytic capacitor C11 is discharged through the be junction of the first triode Q1 through the first resistor R1, the current is Ib_Q1, and the first triode Q1 is saturated and turned on.

[0039] As an optional embodiment, the relay circuit 202 comprises a first power supply 12V, a relay REL and a third diode D3.

[0040] The ACL live wire of the relay REL is connected to the running interface of the motor and the thyristor switching circuit 204, the positive pole of the relay REL is connected to the first power supply 12V and the negative pole of the third diode D3 respectively, and the negative pole of the relay REL is connected to the positive pole of the third diode D3 and the first driving circuit 201 respectively.

[0041] As an optional embodiment, the second driving circuit 203 comprises a second triode Q2, a third resistor R3, a fourth resistor R4, a second electrolytic capacitor C12, a fourth diode D4, a fifth diode D5 and a second capacitor C22.

[0042] The anode of the thyristor Q3 is connected to one end of the fifth resistor R5 and the relay circuit 202, respectively. The cathode of the thyristor Q3 is connected to the running interface of the motor and the negative pole of the third capacitor C23, respectively. The other end of the fifth resistor R5 is connected to the positive pole of the third capacitor C23 and one end of the sixth resistor R6, respectively. The other end of the sixth resistor R6 is connected to pin one of the optocoupler U1. Pin two of the optocoupler U1 is connected to one end of the eighth resistor R8, the positive pole of the fourth capacitor C24 and the control electrode of the thyristor Q3, respectively. The other end of the eighth resistor R8 is connected to the negative pole of the fourth capacitor C24 and the ground, respectively. One end of the seventh resistor R7 is connected to the LED cathode of the optocoupler U1. The other end of the seventh resistor R7 is connected to the second power supply 5V. The LED anode of the optocoupler U1 is connected to the second drive circuit 203. The optocoupler is a thyristor optocoupler. Pin one of the optocoupler U1 can be the collector of an electric detector or the emitter of a photoelectric detector. Pin two of the optocoupler U1 can be the collector of an electric detector or the emitter of a photoelectric detector.

[0043] In this way, when the PWM wave signal sent by the controller to the second drive circuit 202 is high, the current charges the second electrolytic capacitor C12 through the second capacitor C22 and the fourth diode D4 until the voltage is stable. The current flows through the be junction of the second transistor Q2 through the third resistor R3, and the current is Ib_Q2. The second transistor Q2 is saturated and turned on. After the voltage of the second capacitor C22 is full, there is no current through the fourth diode D4. When the PWM wave signal sent by the controller to the second drive circuit 202 is low, the second capacitor C22 is discharged through the fifth diode D5 and the second capacitor C22. The second electrolytic capacitor C12 is discharged through the be junction of the second transistor Q2 through the third resistor R3. The current is Ib_Q2. The second transistor Q2 is saturated and turned on.

[0044] As an optional embodiment, the thyristor switch circuit 204 includes a thyristor Q3, a fifth resistor R5, a sixth resistor R6, an optocoupler U1, a seventh resistor R7, an eighth resistor R8, a second power supply 5V, a third capacitor C23 and a fourth capacitor C24.

[0045] The anode of the thyristor Q3 is connected to one end of the fifth resistor R5 and the relay circuit 202, respectively. The cathode of the thyristor Q3 is connected to the running interface of the motor and the negative pole of the third capacitor C23, respectively. The other end of the fifth resistor R5 is connected to the positive pole of the third capacitor C23 and one end of the sixth resistor R6, respectively. The other end of the sixth resistor R6 is connected to pin one of the optocoupler U1. Pin two of the optocoupler U1 is connected to one end of the eighth resistor R8, the positive pole of the fourth capacitor C24 and the control electrode of the thyristor Q3, respectively. The other end of the eighth resistor R8 is connected to the negative pole of the fourth capacitor C24 and the ground, respectively. One end of the seventh resistor R7 is connected to the LED cathode of the optocoupler U1. The other end of the seventh resistor R7 is connected to the second power supply 5V. The LED anode of the optocoupler U1 is connected to the second drive circuit 203. The optocoupler is a thyristor optocoupler. Pin one of the optocoupler U1 can be the collector of an electric detector or the emitter of a photoelectric detector. Pin two of the optocoupler U1 can be the collector of an electric detector or the emitter of a photoelectric detector.

[0046] In this way, when the second driving circuit 202 is turned on, the primary side of the photocoupler U1 is turned on, and the seventh resistor R7 is the current resistance of the photocoupler U1. According to the amplification factor of the primary and secondary sides of the photocoupler U1, after the primary side of the photocoupler U1 is turned on, the secondary side of the photocoupler U1 can be saturated and turned on. When power is taken through the ACL, the photocoupler U1 secondary side triggers the TRIAC pin of the thyristor Q3 to be turned on through the fifth resistor R5 and the sixth resistor R6. Then, the thyristor Q3 is turned on. The thyristor Q3 can carry a current of 6A in an instant, effectively avoiding the use of a relay REL to generate a switching spark.

[0047] As an optional implementation, when the high-voltage load starts the motor P1, the controller switches the first driving circuit 201 and the second driving circuit 203 to work alternately through the PWM wave signal. In this way, the controller can switch the first driving circuit 201 where the relay REL is located and the second driving circuit 203 where the thyristor Q3 is located alternately to realize the free switching of the two driving circuits of the motor P1. Among them, the free switching can be realized according to the control timing of the controller.

[0048] As an optional implementation, the thyristor Q3 is a low-impedance bidirectional thyristor, and the thyristor Q3 can carry a preset current threshold of instantaneous current. Among them, the preset current threshold can reach 6A, which can effectively avoid the spark generated by the switching of the relay REL.

[0049] As an optional implementation, the duty cycle of the PWM wave signal is 50%. When the controller sends a high-level PWM wave signal to the first driving circuit 201, after the voltage of the first capacitor C21 is full, there is no current through the first diode D1, at this time the first electrolytic capacitor C11 discharges through the first resistor R1 and Vbe_Q1 until the voltage of the be junction of the first transistor Q1 is <Vbe_sat=0.3V, and then the first transistor Q1 is turned off. When the controller sends a low-level PWM wave signal to the first driving circuit 201, the first electrolytic capacitor C11 discharges through the first resistor R1 and the be junction of the first transistor Q1, and then the first transistor Q1 is turned off when the voltage of the first electrolytic capacitor C11 is discharged to <Vbe_sat=0.3V. Therefore, in order to realize the continuous conduction of the first transistor Q1, the PWM duty cycle is designed to be 50% to keep the first transistor Q1 continuously conducting, and to realize the situation that the pin of the first driving circuit 201 connected to the controller is always high or always low in the case of accidental crash, the first transistor Q1 is turned off to avoid safety risks.

[0050] The utility model embodiment provides a switching circuit of motor drive, discarded prior art's IO single level control relay circuit, adopts the driving method of PWM wave signal, two kinds of switchable motor driving circuit, additional isolation control silicon controlled low impedance electronic switch circuit combination, realize zero spark switch, prevent accidental conduction protection, controller control's regulated output, improve the load driving circuit reliable use of home appliance class high pressure. Further reduce the cost, improve the security. Thus improve the motor drive reliable use of household appliance. Improve the development efficiency of developer, shorten the development cycle, improve product reliability lays great foundation.

[0051] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in each embodiment provided by the utility model can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM) and memory bus dynamic RAM (RDRAM) and the like.

[0052] It should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0053] It also needs to be explained that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for display, analyzed data, etc.) involved in the utility model are all information and data authorized by the user or authorized by all parties.

[0054] Each embodiment in the specification is described in a related manner, and the same and similar parts between each embodiment can be referred to each other, and each embodiment focuses on the difference from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the related parts can be referred to the part of the method embodiment.

[0055] The technical features of the above embodiments can be combined arbitrarily, in order to make the description simple, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the specification.

[0056] The above-described embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but it should not be understood as the limitation of the scope of the invention patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, which belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. A switching circuit for motor drive, characterized in that, The switching circuit includes a first driving circuit, a relay circuit, a second driving circuit, and a thyristor switching circuit; wherein, The first drive circuit is connected to the relay circuit and the controller respectively, and the relay circuit is connected to the motor's running interface and the thyristor switch circuit respectively. The second drive circuit is connected to the thyristor switch circuit and the controller respectively, and the thyristor switch circuit is connected to the motor's operating interface; The first driving circuit is used to receive the PWM wave signal sent by the controller, and is in a conducting state to supply power to the relay circuit; The relay circuit is used to be turned on when the first driving circuit is turned on, so as to drive the motor to run. The second driving circuit is used to receive the PWM wave signal sent by the controller, and is in a conducting state to supply power to the thyristor switching circuit; The thyristor switching circuit is used to turn on the thyristor when the second driving circuit is turned on, thereby driving the motor to run.

2. The switching circuit according to claim 1, characterized in that, The first driving circuit includes a first transistor, a first resistor, a second resistor, a first electrolytic capacitor, a first diode, a second diode, and a first capacitor; The collector of the first transistor is connected to the relay circuit, the base of the first transistor is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the positive terminal of the first electrolytic capacitor and the negative terminal of the first diode, the emitter of the first transistor is connected to the other end of the second resistor, the negative terminal of the first electrolytic capacitor and the positive terminal of the second diode and grounded, the positive terminal of the first diode is connected to the negative terminal of the second diode and the negative terminal of the first capacitor, and the positive terminal of the first capacitor is connected to the controller.

3. The switching circuit according to claim 1, characterized in that, The relay circuit includes a first power supply, a relay, and a third diode; The relay's ACL live wire is connected to the motor's operating interface and the thyristor switch circuit. The relay's positive terminal is connected to the first power supply and the negative terminal of the third diode, respectively. The relay's negative terminal is connected to the positive terminal of the third diode and the first drive circuit, respectively.

4. The switching circuit according to claim 1, characterized in that, The second driving circuit includes a second transistor, a third resistor, a fourth resistor, a second electrolytic capacitor, a fourth diode, a fifth diode, and a second capacitor; The collector of the second transistor is connected to the thyristor switching circuit, the base of the second transistor is connected to one end of the third resistor, the other end of the third resistor is connected to one end of the fourth resistor, the positive terminal of the second electrolytic capacitor and the negative terminal of the fourth diode, the emitter of the second transistor is connected to the other end of the fourth resistor, the negative terminal of the second electrolytic capacitor and the positive terminal of the fifth diode and grounded, the positive terminal of the fourth diode is connected to the negative terminal of the second capacitor and the negative terminal of the fifth diode, and the positive terminal of the second capacitor is connected to the controller.

5. The switching circuit according to claim 1, characterized in that, The thyristor switching circuit includes a thyristor, a fifth resistor, a sixth resistor, an optocoupler, a seventh resistor, an eighth resistor, a second power supply, a third capacitor, and a fourth capacitor; The anode of the thyristor is connected to one end of the fifth resistor and the relay circuit, the cathode of the thyristor is connected to the motor's operating interface and the negative terminal of the third capacitor, the other end of the fifth resistor is connected to the positive terminal of the third capacitor and one end of the sixth resistor, the other end of the sixth resistor is connected to pin one of the optocoupler, pin two of the optocoupler is connected to one end of the eighth resistor, the positive terminal of the fourth capacitor and the control terminal of the thyristor, the other end of the eighth resistor is connected to the negative terminal of the fourth capacitor and grounded, the LED cathode of the optocoupler is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to the second power supply, and the LED anode of the optocoupler is connected to the second driving circuit.

6. The switching circuit according to claim 1, characterized in that, When the high-voltage load starts the motor, the controller switches the first drive circuit and the second drive circuit to work alternately through a PWM wave signal.

7. The switching circuit according to claim 5, characterized in that, The thyristor is a low-impedance bidirectional thyristor, which can carry instantaneous current of a preset current threshold.

8. The switching circuit according to claim 1, characterized in that, The duty cycle of the PWM wave signal is 50%.

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