Motor driving circuit, hardware motor speed regulation circuit and intelligent household appliance

Abstract

The utility model provides a motor driving circuit, a hardware motor speed regulation circuit and an intelligent household electrical appliance, the hardware motor speed regulation circuit uses a voltage-regulator tube to control the on state of a unijunction transistor, so as to control the conduction angle of a silicon controlled rectifier based on the output pulse of the unijunction transistor, thereby realizing the control of the rotating speed of a motor without using a high-cost single-chip microcomputer and a chip. The cost for controlling the rotating speed of the motor is greatly reduced; under the condition that software control is not used, a hardware circuit is used for adjusting the speed of the alternating-current motor, feedback adjustment is carried out when the load of the motor is increased, and therefore it is guaranteed that the rotating speed of the motor is not reduced due to the fact that the load is increased.

Description

Technical Field

[0001] The present disclosure relates to the technical field of motor speed regulation, and in particular to a motor drive circuit, a hardware motor speed regulation circuit and a smart home appliance. Background Art

[0002] In the power electronics industry, the circuits commonly used to control the motor speed generally use a single-chip microcomputer to control the conduction angle of the thyristor to control the motor speed. When the motor is stalled, the conduction angle is also adjusted by the chip so that the motor can still maintain a fixed speed after stalling. However, the above-mentioned solution of using a single-chip microcomputer and chip to control the motor speed has problems such as high cost. Utility Model Content

[0003] The technical problem to be solved by the present disclosure is to overcome the defect of high cost of controlling motor speed in the prior art, and to provide a motor drive circuit, a hardware motor speed control circuit and a smart home appliance.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] According to a first aspect of the present disclosure, a motor drive circuit is provided, the motor drive circuit comprising a first voltage regulator tube, a second voltage regulator tube, a switch device, a capacitor and a power controller;

[0006] The first end of the first voltage regulator tube, the second end of the capacitor, the third end of the second voltage regulator tube, the fourth end of the switch device and the fifth end of the power controller are all connected to the power supply end;

[0007] The sixth terminal of the first voltage regulator tube, the seventh terminal of the capacitor and the eighth terminal of the power controller are all connected to the ground terminal;

[0008] The third end of the second voltage regulator tube is connected to the second end of the capacitor;

[0009] The ninth terminal of the second voltage regulator tube is connected to the tenth terminal of the switch device;

[0010] The eleventh terminal of the switch device is connected to the twelfth terminal of the power controller;

[0011] The first voltage regulator tube is used to maintain the supply voltage inputted by the power supply end at a first preset voltage;

[0012] The second voltage regulator is used to trigger the switch device to output a pulse signal based on the capacitor reaching a second preset voltage;

[0013] The power controller is used to reach a conducting state based on the output pulse signal to adjust the speed of the AC motor;

[0014] Wherein, the first preset voltage is greater than the second preset voltage.

[0015] Preferably, the power controller is a thyristor;

[0016] The input end of the thyristor is connected to the power supply end;

[0017] The output end of the thyristor is connected to the ground end;

[0018] The control end of the thyristor is connected to the eleventh end of the switch device.

[0019] Preferably, the switching device is a unijunction transistor.

[0020] Preferably, the single junction transistor is a triode;

[0021] The collector of the triode is connected to the power supply end;

[0022] The emitter of the triode is connected to the control end of the thyristor;

[0023] The base of the transistor is connected to the ninth end of the second voltage regulator tube.

[0024] Preferably, the unijunction transistor is an NMOS (N-type metal oxide semiconductor) tube;

[0025] The drain of the NMOS tube is connected to the power supply end;

[0026] The source of the NMOS tube is connected to the control terminal of the thyristor;

[0027] The gate of the NMOS tube is connected to the ninth terminal of the second voltage regulator tube;

[0028] or,

[0029] The unijunction transistor is a PMOS (positive channel metal oxide semiconductor) tube;

[0030] The source of the PMOS tube is connected to the power supply end;

[0031] The drain of the PMOS tube is connected to the control end of the thyristor;

[0032] The gate of the PMOS tube is connected to the ninth end of the second voltage regulator tube.

[0033] Preferably, the motor drive circuit further includes a first resistor;

[0034] One end of the first resistor is connected to the power supply end, and the other end of the first resistor is respectively connected to the fourth end of the switch device, the second end of the capacitor, and the first end of the first voltage regulator tube;

[0035] and / or,

[0036] The motor drive circuit further includes a second resistor;

[0037] One end of the second resistor is connected to the fourth end of the switch device and the first end of the first voltage regulator tube respectively, and the other end of the second resistor is connected to the second end of the capacitor;

[0038] and / or,

[0039] The motor drive circuit further includes a third resistor;

[0040] One end of the third resistor is connected to the output end of the thyristor, and the other end of the third resistor is connected to the ground end.

[0041] According to a second aspect of the present disclosure, a hardware motor speed regulation circuit is provided, wherein the hardware motor speed regulation circuit comprises the motor drive circuit described in the first aspect of the present disclosure.

[0042] Preferably, the hardware motor speed control circuit further includes a rectifier circuit;

[0043] The rectifier circuit and the motor drive circuit are connected in series to a power supply network, and the rectifier circuit is electrically connected to the AC motor;

[0044] The rectifier circuit is used to rectify the alternating current input from the power supply network into direct current, so as to output a supply voltage to the motor drive circuit;

[0045] Wherein, when the power controller in the motor drive circuit is in the on state, the speed of the AC motor is regulated via the rectifier circuit.

[0046] Preferably, the rectifier circuit is a bridge rectifier circuit.

[0047] According to a third aspect of the present disclosure, a smart home appliance is provided, characterized in that the smart home appliance includes an AC motor and the hardware motor speed control circuit described in the second aspect of the present disclosure.

[0048] The positive and progressive effect of the present invention lies in that the present invention utilizes a voltage regulator to control the on-state of a unijunction transistor, thereby controlling the conduction angle of a thyristor based on the output pulse of the unijunction transistor, thereby realizing control of the motor speed, without the need for high-cost single-chip microcomputers and chips, and greatly reducing the cost of controlling the motor speed; and without using software control, a hardware circuit is used to realize speed regulation of the AC motor, so as to perform feedback adjustment when the motor load increases, thereby ensuring that the motor speed does not decrease due to increased load. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a first motor driving circuit diagram of Embodiment 1 of the present disclosure;

[0050] Figure 2 is a second motor driving circuit diagram of Embodiment 1 of the present disclosure;

[0051] Figure 3 This is the hardware motor speed control circuit diagram of embodiment 2 of the present disclosure. DETAILED DESCRIPTION

[0052] A preferred embodiment is given below, and the present disclosure is described more clearly and completely in conjunction with the accompanying drawings.

[0053] Example 1

[0054] See also Figure 1 In a specific embodiment of the present disclosure, a motor drive circuit is provided, the motor drive circuit comprising a first voltage regulator tube D1, a second voltage regulator tube D2, a switch device Q, a capacitor C and a power controller K;

[0055] The first end of the first voltage regulator tube D1, the second end of the capacitor C, the third end of the second voltage regulator tube D2, the fourth end of the switch device Q and the fifth end of the power controller K are all connected to the power supply terminal VCC;

[0056] The sixth terminal of the first voltage regulator tube D1, the seventh terminal of the capacitor C and the eighth terminal of the power controller K are all connected to the ground terminal GND;

[0057] The third end of the second voltage regulator tube D2 is connected to the second end of the capacitor C;

[0058] The ninth terminal of the second voltage regulator tube D2 is connected to the tenth terminal of the switch device Q;

[0059] The eleventh terminal of the switch device Q is connected to the twelfth terminal of the power controller K;

[0060] The first voltage regulator D1 is used to maintain the supply voltage input by the power supply terminal VCC at a first preset voltage;

[0061] The second voltage regulator D2 is used to trigger the switch device Q to output a pulse signal based on the capacitor C reaching a second preset voltage;

[0062] The power controller K is used to reach a conducting state based on the output pulse signal to adjust the speed of the AC motor;

[0063] Wherein, the first preset voltage is greater than the second preset voltage.

[0064] Specifically, the two ends of the first voltage regulator D1 are the first end and the sixth end, the two ends of the capacitor C are the second end and the seventh end, the two ends of the second voltage regulator D2 are the third end and the ninth end, the switching device Q has three ports, namely the fourth end, the tenth end and the eleventh end, and the power controller K also has three ports, namely the fifth end, the eighth end and the twelfth end.

[0065] In this embodiment, the first preset voltage is a total limiting voltage, which is used to convert the input voltage of the power supply terminal VCC into a first preset voltage so that the entire motor drive circuit can operate under the first preset voltage environment. The second preset voltage is the turn-on voltage of the second voltage regulator D2, which is less than the first preset voltage value. When the voltage of the capacitor C reaches the second preset voltage, the second voltage regulator D2 is turned on to trigger the switch device Q to turn on the output pulse signal, so that the power controller K is turned on, thereby realizing the speed regulation of the motor.

[0066] In a specific embodiment, the power controller K is a thyristor BT1; wherein the fifth end of the power controller K is the input end of the thyristor BT1, connected to the power supply end VCC; the eighth end of the power controller K is the output end of the thyristor BT1, connected to the ground end GND; the twelfth end of the power controller K is the control end of the thyristor BT1, connected to the eleventh end of the switching device Q.

[0067] In a specific embodiment, the switching device Q is a single junction transistor, for example, a triode and a MOS tube. When the single junction transistor is a triode, the collector c of the triode is connected to the power supply terminal VCC, the emitter e is connected to the control terminal of the thyristor BT1, and the base b is connected to the ninth terminal of the second voltage regulator tube D2.

[0068] If the single junction transistor is a MOS tube, the corresponding ports are connected according to different MOS tube types. For example, when the MOS tube is an NMOS tube, the drain of the NMOS tube is connected to the power supply terminal VCC, the source is connected to the control terminal of the thyristor BT1, and the gate is connected to the ninth terminal of the second voltage regulator tube D2; and when the MOS tube is a PMOS tube, the source of the PMOS tube is connected to the power supply terminal VCC, the drain is connected to the control terminal of the thyristor BT1, and the gate is connected to the ninth terminal of the second voltage regulator tube D2.

[0069] In a specific embodiment, Figure 2As shown, the motor drive circuit also includes a first resistor R1, a second resistor R2, and a third resistor R3, wherein one end of the first resistor R1 is connected to the power supply end VCC, and the other end is respectively connected to the fourth end of the switch device Q, the second end of the capacitor C, and the first end of the first voltage regulator D1; one end of the second resistor R2 is respectively connected to the fourth end of the switch device Q and the first end of the first voltage regulator D1, and the other end is connected to the second end of the capacitor C; one end of the third resistor R3 is connected to the output end of the thyristor BT1, and the other end is connected to the ground end GND.

[0070] In a specific implementation, the second resistor R2 is a variable resistor. By changing the resistance of the second resistor R2, the charging time of the capacitor C can be changed, thereby changing the opening angle of the thyristor BT1.

[0071] This embodiment uses a Zener diode to control the on-state of a single junction transistor, so as to control the conduction angle of a thyristor based on the output pulse of the single junction transistor, thereby realizing the control of the motor speed. No high-cost single-chip microcomputer and chip are required, thus greatly reducing the cost of controlling the motor speed. In addition, without using software control, a hardware circuit is used to realize speed regulation of the AC motor, so as to perform feedback adjustment when the motor load increases, thereby ensuring that the motor speed does not decrease due to increased load.

[0072] Example 2

[0073] like Figure 3 As shown, a hardware motor speed regulation circuit is provided, and the hardware motor speed regulation circuit includes the motor drive circuit described in Example 1.

[0074] In a specific implementation, the hardware motor speed control circuit further includes a rectifier circuit D3, which may be a bridge rectifier circuit. The rectifier circuit D3 is connected in series with the motor drive circuit and connected to the power supply network. The rectifier circuit D3 is electrically connected to the AC motor M.

[0075] The rectifier circuit D3 is used to rectify the AC power input from the L end of the power supply network into DC power to output the power supply voltage to the motor drive circuit. When the power controller in the motor drive circuit is in the on state, a loop is formed through the rectifier circuit to the N end to adjust the speed of the AC motor M.

[0076] The working principle of the hardware motor speed control circuit of this embodiment is as follows:

[0077] The rectifier circuit D3 is connected in series with the motor M in the circuit, and the rectifier circuit D3 provides a full-wave rectified voltage to the thyristor BT1. When the thyristor BT1 is turned on, the rectifier circuit D3 and the thyristor BT1 are in a low-resistance state, and the motor M works. As long as the conduction angle of the thyristor BT1 is changed, the voltage drop of the thyristor BT1 can be changed, resulting in a change in the voltage across the motor M, thereby achieving the purpose of voltage and speed regulation. The terminal voltage U of the motor M is m =U1-U D3 -U BT1 -U R3 , in the above formula, U D3 , U BT1 The pressure drop is very small, and the feedback U R3 The terminal voltage of the motor M is also not large, so the terminal voltage of the motor M is simplified to U m =U1-U vs ;

[0078] The trigger pulse of the thyristor BT1 is generated by the single junction transistor, and the capacitor C is charged to the stable voltage U of the first voltage regulator tube D1 through the second resistor R2. D1 , when the capacitor C is charged to U D2 When the voltage is high, the unijunction transistor turns on the output pulse to turn on the thyristor BT1. By changing the resistance value of R2, the charging time of the capacitor C can be changed, the opening angle of the thyristor BT1 can be changed, and the speed of the motor M can be changed. After the base voltage of the unijunction transistor is fully attenuated, the unijunction transistor is disconnected, and once the thyristor BT1 is turned on, the voltage between the power supply terminal VCC and the ground terminal GND drops to the voltage of the first voltage regulator U D1 Below the stable voltage UZ, the recharging of capacitor C depends on the voltage of the power supply terminal VCC. D1 The voltage of the power supply terminal VCC has been reduced to outside its conduction area, and the voltage of the power supply terminal VCC depends on the current of the motor M, the third resistor R3 and the voltage drop when the thyristor BT1 is turned on.

[0079] Among them, during the conduction period of the thyristor BT1, the capacitor C cannot be charged to a high voltage sufficient to trigger the single junction transistor again, but the capacitor C will be charged to a certain value determined by the current of the motor M. If the current of the motor increases during a certain conduction period (for example, when the motor is blocked and the speed is slow, the current will increase), the voltage on the capacitor C will also increase, so at the beginning of the next period, the capacitor C will not take so long to charge to the peak voltage of the single crystal. In this case, the trigger angle is reduced (the conduction angle is larger), and the root voltage applied to the motor M increases proportionally, resulting in an increase in effective torque. In this way, when the thyristor BT1 is turned on, the charging current of the capacitor C depends on the current of the motor M, the charging speed of the capacitor C becomes faster, the output pulse time of the triggering single junction transistor becomes shorter, and then the speed of the motor is increased. In this case, feedback is obtained, which makes the problem of torque loss of the motor M at low speed compensated.

[0080] This embodiment uses a Zener diode to control the on-state of a single junction transistor, so as to control the conduction angle of a thyristor based on the output pulse of the single junction transistor, thereby realizing the control of the motor speed. No high-cost single-chip microcomputer and chip are required, thus greatly reducing the cost of controlling the motor speed. In addition, without using software control, a hardware circuit is used to realize speed regulation of the AC motor, so as to perform feedback adjustment when the motor load increases, thereby ensuring that the motor speed does not decrease due to increased load.

[0081] Example 3

[0082] This embodiment provides a smart home appliance, which includes an AC motor and the hardware motor speed control circuit described in Embodiment 2 of the present disclosure.

[0083] In specific implementation, the hardware motor speed control circuit in this embodiment 2 can be applied to various smart home appliances to control the speed of the motors in the smart home appliances, for example, electric blenders, multi-function food processors and other smart home appliances. This embodiment does not make specific limitations on this.

[0084] This embodiment sets the hardware motor speed control circuit in Example 2 in the smart home appliance, uses a voltage regulator to control the on-state of a single junction transistor, and controls the conduction angle of a thyristor based on the output pulse of the single junction transistor to control the motor speed. This eliminates the need for high-cost single-chip microcomputers and chips, and greatly reduces the cost of controlling the motor speed. In addition, without using software control, a hardware circuit is used to control the speed of the AC motor, so that feedback adjustment is performed when the motor load increases, thereby ensuring that the motor speed does not decrease due to increased load.

[0085] Although the specific embodiments of the present disclosure are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

1. A motor drive circuit, characterized in that: The motor drive circuit includes a first voltage regulator tube, a second voltage regulator tube, a switch device, a capacitor and a power controller; The first end of the first voltage regulator tube, the second end of the capacitor, the third end of the second voltage regulator tube, the fourth end of the switch device and the fifth end of the power controller are all connected to the power supply end; The sixth terminal of the first voltage regulator tube, the seventh terminal of the capacitor and the eighth terminal of the power controller are all connected to the ground terminal; The third end of the second voltage regulator tube is connected to the second end of the capacitor; The ninth terminal of the second voltage regulator tube is connected to the tenth terminal of the switch device; The eleventh terminal of the switch device is connected to the twelfth terminal of the power controller; The first voltage regulator tube is used to maintain the supply voltage inputted by the power supply end at a first preset voltage; The second voltage regulator is used to trigger the switch device to output a pulse signal based on the capacitor reaching a second preset voltage; The power controller is used to reach a conducting state based on the output pulse signal to adjust the speed of the AC motor; Wherein, the first preset voltage is greater than the second preset voltage.

2. The motor drive circuit according to claim 1, characterized in that: The power controller is a thyristor; The input end of the thyristor is connected to the power supply end; The output end of the thyristor is connected to the ground end; The control end of the thyristor is connected to the eleventh end of the switch device.

3. The motor drive circuit according to claim 2, characterized in that: The switching device is a unijunction transistor.

4. The motor drive circuit according to claim 3, characterized in that: The unijunction transistor is a triode; The collector of the triode is connected to the power supply end; The emitter of the triode is connected to the control end of the thyristor; The base of the transistor is connected to the ninth end of the second voltage regulator tube.

5. The motor drive circuit according to claim 3, characterized in that: The single junction transistor is an NMOS tube; The drain of the NMOS tube is connected to the power supply end; The source of the NMOS tube is connected to the control terminal of the thyristor; The gate of the NMOS tube is connected to the ninth terminal of the second voltage regulator tube; or, The single junction transistor is a PMOS tube; The source of the PMOS tube is connected to the power supply end; The drain of the PMOS tube is connected to the control end of the thyristor; The gate of the PMOS tube is connected to the ninth end of the second voltage regulator tube.

6. The motor drive circuit according to any one of claims 2 to 5, characterized in that: The motor drive circuit further includes a first resistor; One end of the first resistor is connected to the power supply end, and the other end of the first resistor is respectively connected to the fourth end of the switch device, the second end of the capacitor, and the first end of the first voltage regulator tube; and / or, The motor drive circuit further includes a second resistor; One end of the second resistor is connected to the fourth end of the switch device and the first end of the first voltage regulator tube respectively, and the other end of the second resistor is connected to the second end of the capacitor; and / or, The motor drive circuit further includes a third resistor; One end of the third resistor is connected to the output end of the thyristor, and the other end of the third resistor is connected to the ground end.

7. A hardware motor speed control circuit, characterized in that: The hardware motor speed control circuit comprises a motor drive circuit as claimed in any one of claims 1 to 6.

8. The hardware motor speed control circuit according to claim 7, characterized in that: The hardware motor speed regulation circuit also includes a rectifier circuit; The rectifier circuit and the motor drive circuit are connected in series to a power supply network, and the rectifier circuit is electrically connected to the AC motor; The rectifier circuit is used to rectify the alternating current input from the power supply network into direct current, so as to output a supply voltage to the motor drive circuit; Wherein, when the power controller in the motor drive circuit is in the on state, the speed of the AC motor is regulated via the rectifier circuit.

9. The hardware motor speed control circuit according to claim 8, characterized in that: The rectifier circuit is a bridge rectifier circuit.

10. A smart home appliance, characterized in that: The smart home appliance includes an AC motor and a hardware motor speed control circuit as described in any one of claims 7 to 9.

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