Power supply circuit and food processor comprising same

Abstract

The utility model provides a power supply circuit and a food processor comprising the same. The power supply circuit is applied to the food processor. The power supply circuit comprises a first power input end, a second power input end, a transformer and a filtering and rectifying circuit. The transformer comprises a primary winding and a secondary winding. The primary winding is connected with the first power input end and the second power input end. The filtering and rectifying circuit comprises a positive temperature coefficient thermistor, a rectifying circuit and a filtering circuit which are sequentially connected in series between the first power input end and the primary winding. The filtering and rectifying circuit is arranged between the first power supply input end and the primary winding of the transformer, the filtering and rectifying circuit comprises the positive temperature coefficient thermistor, the rectifying circuit and the filtering circuit, the filtering and rectifying circuit can reduce electromagnetic interference of the power supply circuit, the resistance value of the positive temperature coefficient thermistor is increased when current rises, and the filtering circuit is switched on. When the transformer has turn-to-turn short circuit, the positive temperature coefficient thermistor can limit over-high current and can protect the power supply circuit.

Description

Technical Field

[0001] The present application relates to the technical field of small household appliances, and in particular to a power supply circuit and a food processor including the same. Background Art

[0002] With the improvement of living standards, many different types of food processors have appeared on the market. The functions of food processors may include, but are not limited to, making soy milk, squeezing juice, making rice paste, mincing meat, shaving ice, making coffee and / or preparing facial masks, etc.

[0003] Due to the instability of the mains electricity, abnormally high voltage may occur, causing the transformer in the power circuit of the food processor to short-circuit, posing a safety hazard to the food processor. At the same time, the electromagnetic interference in the power circuit will also affect the normal operation of the food processor. By setting a series fuse in the power circuit, the circuit can be disconnected when the current rises abnormally, thus playing a current limiting role. However, the above method requires frequent maintenance and replacement of the fuse, which brings inconvenience to the user. Utility Model Content

[0004] The present application provides a power supply circuit and a food processor including the same, which can prevent the circuit current from being too high and reduce electromagnetic interference.

[0005] The present application provides a power supply circuit, which is applied to a food processor, comprising:

[0006] a first power input terminal and a second power input terminal;

[0007] a transformer, comprising a primary winding and a secondary winding, wherein the primary winding is connected to the first power input terminal and the second power input terminal; and

[0008] The filter and rectifier circuit comprises a positive temperature coefficient thermistor, a rectifier circuit and a filter circuit which are connected in series between the first power input terminal and the primary winding.

[0009] In some embodiments, the filter rectifier circuit can reduce electromagnetic interference of the power supply circuit. The resistance of the positive temperature coefficient thermistor increases when the current increases. When a short circuit occurs between turns of the transformer, the current can be limited to be too high to protect the power supply circuit.

[0010] Optionally, the power supply circuit further includes an isolated power supply circuit electrically connected to the secondary winding. In some embodiments, the isolated power supply circuit is used to output an isolated voltage, which can improve the safety of the circuit.

[0011] Optionally, the transformer further includes an auxiliary winding coupled to the primary winding, and the power supply circuit further includes a non-isolated power supply circuit electrically connected to the auxiliary winding. In some embodiments, the non-isolated power supply circuit is used to output a non-isolated voltage and is connected to the auxiliary winding, which can save space.

[0012] Optionally, the power supply circuit further includes a switching power supply electrically connected between the first power supply input terminal and the primary winding, and the switching power supply is electrically connected to the non-isolated power supply circuit, and the non-isolated power supply circuit is used to power the switching power supply. In some embodiments, the switching power supply can efficiently adjust the output voltage of the non-isolated power supply circuit.

[0013] Optionally, the power supply circuit further includes a controller and a voltage detection circuit;

[0014] The voltage detection circuit includes a diode, a first capacitor, a second capacitor, a first resistor, a second resistor, a third resistor, a first power supply terminal and a first ground terminal; the cathode of the diode is connected to the secondary winding, the diode, the first resistor, and the first capacitor are connected in series between the secondary winding and the first ground terminal in sequence, the third resistor, the second resistor, and the first capacitor are connected in series between the first power supply terminal and the first ground terminal in sequence, and the second capacitor and the third resistor are connected in parallel;

[0015] The controller includes a voltage detection port connected between the second resistor and the third resistor. In some embodiments, the voltage detection circuit can detect the voltage change of the power supply circuit, so that the controller can obtain the output voltage of the power supply circuit in time.

[0016] Optionally, the power supply circuit further includes a controller and a zero-crossing detection circuit, and the controller includes a zero-crossing detection port;

[0017] The zero-crossing detection circuit includes a photocoupler, a second power supply terminal and a second ground terminal, the photocoupler includes a first input terminal and a second input terminal, the first input terminal is connected between the positive temperature coefficient thermistor and the rectifier circuit, and the second input terminal is connected to the second power supply input terminal; the output terminal of the photocoupler is connected to the second power supply terminal and the zero-crossing detection port. In some embodiments, the zero-crossing detection circuit can detect the zero-crossing point of the power supply circuit, so that the controller can respond according to the change of the power supply circuit.

[0018] Optionally, the rectifier circuit further includes a first diode and a second diode, the anode of the first diode is connected to the first power input terminal, the anode of the second diode is connected to the second power input terminal, and the cathodes of the first diode and the second diode are both connected to the filter circuit. In some embodiments, the rectifier circuit performs a rectifying function and can convert alternating current into direct current, so that the power supply circuit can output direct current.

[0019] Optionally, the rectifier circuit includes a third diode and a fourth diode, the cathode of the third diode is connected to the first power input terminal, the cathode of the fourth diode is connected to the second power input terminal, and the anodes of the third diode and the fourth diode are grounded. In some embodiments, the third diode and the fourth diode can prevent the power polarity from being reversed, protecting other components in the circuit from being damaged.

[0020] Optionally, the filter circuit includes a color ring inductor. In some embodiments, the color ring inductor can reduce electromagnetic interference of the circuit and stabilize the current.

[0021] The present application also provides a food processor, comprising:

[0022] load;

[0023] A driving circuit connected to the load and used to drive the load;

[0024] The power supply circuit as described in any one of the above items is connected to the driving circuit and is used to supply power to the driving circuit.

[0025] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0027] Figure 1 Shown is a schematic structural diagram of an embodiment of a food processor of the present application.

[0028] Figure 2 Shown Figure 1 A partial circuit block diagram of an embodiment of a food processor is shown.

[0029] Figure 3 FIG. 1 is a circuit diagram of an embodiment of a power supply circuit of the present application.

[0030] Figure 4 Shown is a circuit diagram of another embodiment of the power supply circuit of the present application. DETAILED DESCRIPTION

[0031] The present application provides a power supply circuit and a food processor including the same. The power supply circuit and the food processor including the same are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0032] Figure 1FIG. 1 is a schematic diagram of the structure of an embodiment of a food processor 10 of the present application. Figure 1 As shown, the food processor 10 includes a main unit 11 and a food processor 12 .

[0033] In some embodiments, the host 11 is in the form of a stand. The host 11 can provide electrical energy, control and drive the food processor 10 to work, and can interact with the user.

[0034] The cooking cup 12 can be assembled to the main unit 11. In some embodiments, the cooking cup 12 can be detachably mounted to the main unit 11. The cooking cup 12 can hold ingredients for cooking. When the cooking cup 12 is mounted to the main unit 11, the main unit 11 can control the food processor 10 to cook, such as whipping and heating the ingredients. Figure 1 This is only an exemplary embodiment of the food processor, and the present application is not limited to Figure 1 The food processor shown may be other types of food processors.

[0035] Figure 2 Shown Figure 1 FIG. 1 is a partial circuit diagram of an embodiment of a food processor 10 shown in FIG. Figure 2 As shown, the food processor 10 includes: a load 13, a driving circuit 14 and a power supply circuit 20 provided in the present application.

[0036] The drive circuit 14 is connected to the load 13 and is used to drive the load 13. In some embodiments, the load 13 includes a motor, which is used to drive components such as a stirring blade to cook the food. The drive circuit 14 includes a motor drive circuit, which can drive the load 13 to operate in a predetermined manner.

[0037] The power supply circuit 20 is connected to the driving circuit 14 and is used to supply power to the driving circuit 14. The power supply circuit 20 provides power to the driving circuit 14 so that the driving circuit 14 can drive the load 13 to work.

[0038] Figure 3 FIG. 2 is a circuit diagram of an embodiment of a power supply circuit 20 of the present application. The power supply circuit 20 is applied to a food processor 10. Figure 3 As shown, the power supply circuit 20 includes: a first power input terminal L, a second power input terminal N, a transformer 21 and a filter and rectifying circuit 22 .

[0039] The first power input terminal L and the second power input terminal N are used to connect to an external power source, such as a mains power supply.

[0040] The transformer 21 includes a primary winding 211 and a secondary winding 212. The transformer 21 is used to convert the input voltage of the first power input terminal L and the second power input terminal N into the power supply voltage required by the food processor 10. The primary winding 211 is connected to the first power input terminal L and the second power input terminal N. Both ends of the primary winding 211 are respectively connected to the first power input terminal L and the second power input terminal N, and receive the input voltage from the first power input terminal L and the second power input terminal N. The secondary winding 212 is used to output the transformed voltage.

[0041] The filter rectifier circuit 22 includes a positive temperature coefficient thermistor 221, a rectifier circuit 222 and a filter circuit 223 which are connected in series between the first power input terminal L and the primary winding 211. The filter rectifier circuit 22 can rectify and filter the voltage from the first power input terminal L and convert it into a smooth DC voltage.

[0042] The positive temperature coefficient thermistor 221 has the characteristic that the resistance value increases when the temperature rises. When the power supply circuit 20 is working normally, the positive temperature coefficient thermistor 221 allows normal working current to pass. When the current of the power supply circuit 20 increases abnormally, for example, a turn-to-turn short circuit occurs in the transformer 21, the resistance value of the positive temperature coefficient thermistor 221 increases, thereby limiting the current, preventing excessive impact current from damaging circuit components, and improving the safety of the circuit. In the case where the positive temperature coefficient thermistor 221 does not break down, when the fault of the power supply circuit 20 is eliminated, the current decreases, and the resistance of the positive temperature coefficient thermistor 221 decreases accordingly, and the power supply circuit 20 returns to normal working state, which can reduce circuit maintenance and component replacement.

[0043] The rectifier circuit 222 can convert the AC voltage from the first power input terminal L into a DC voltage. The filter circuit 223 can further filter the voltage rectified by the rectifier circuit 222 to make it smoother and reduce the electromagnetic interference of the power supply circuit 20.

[0044] In some embodiments, the filter rectifier circuit 22 can reduce the electromagnetic interference of the power supply circuit 20. The resistance of the positive temperature coefficient thermistor 221 increases when the current increases. When a short circuit occurs between turns of the transformer 21, the current can be limited to be too high to protect the power supply circuit 20.

[0045] Figure 4 FIG. 2 is a circuit diagram of another embodiment of the power supply circuit 20 of the present application.

[0046] refer to Figure 4, the rectifier circuit 222 includes a first diode D1 and a second diode D2. The anode of the first diode D1 is connected to the first power input terminal L, the anode of the second diode D2 is connected to the second power input terminal N, and the cathodes of the first diode D1 and the second diode D2 are both connected to the filter circuit 223. The anode of the first diode D1 receives the positive half cycle of the AC voltage from the first power input terminal L. Due to the working characteristics of the diode, the diode will only be turned on when the anode voltage is higher than the cathode voltage. Therefore, during the positive half cycle of the AC voltage, the first diode D1 is turned on, allowing current to pass. The anode of the second diode D2 is connected to the second power input terminal N. During the negative half cycle of the AC voltage, the anode voltage of the second diode D2 is lower than its cathode voltage, so the second diode D2 is not turned on. In this way, the second diode D2 prevents the current from passing during the negative half cycle, ensuring that only the voltage of the positive half cycle is transmitted to the filter circuit 223.

[0047] The cathodes of the first diode D1 and the second diode D2 are both connected to the filter circuit 223. When the first diode D1 and / or the second diode D2 are turned on, current flows through their cathodes to the filter circuit 223. In this way, the rectifier circuit 222 realizes the rectification of the AC voltage, that is, only the voltage of the positive half cycle is allowed to pass, and the voltage of the negative half cycle is blocked.

[0048] In some embodiments, the first diode D1 and the second diode D2 include diodes with lower forward voltage drop and faster switching speed, so as to optimize the rectification effect. In some embodiments, the rectification circuit 222 performs rectification and can convert AC power into DC power, so that the power supply circuit 20 can output DC power.

[0049] The rectifier circuit 222 includes a third diode D3 and a fourth diode D4. The cathode of the third diode D3 is connected to the first power input terminal L, the cathode of the fourth diode D4 is connected to the second power input terminal N, and the anodes of the third diode D3 and the fourth diode D4 are grounded.

[0050] The third diode D3 and the fourth diode D4 can be turned on in the positive and negative half cycles of the AC voltage, respectively. During the positive half cycle of the AC voltage, the cathode voltage of the third diode D3 is higher than its anode, the third diode D3 is turned on, and the current flows from the first power input terminal L to the ground through the third diode D3. The cathode voltage of the fourth diode D4 is also higher than its anode, but since the anode of the fourth diode D4 is grounded, the fourth diode D4 is not turned on, so the current does not pass through the fourth diode D4.

[0051] During the negative half cycle of the AC voltage, the cathode voltage of the fourth diode D4 is lower than the anode voltage thereof, the fourth diode D4 is turned on, while the third diode D3 is turned off, thereby preventing the reverse flow of current.

[0052] In some embodiments, the third diode D3 and the fourth diode D4 can prevent the polarity of the power supply from being reversed due to their unidirectional conductivity, thereby protecting other components in the circuit from being damaged.

[0053] The filter circuit 223 includes a color ring inductor L1. The color ring inductor L1 can effectively suppress high-frequency noise and ripple in the input voltage through its inductance characteristics. When there is an AC component in the DC power supply, the color ring inductor L1 will generate an inductive reactance, which will hinder the passage of the AC component and filter it out. The color ring inductor L1 makes the DC voltage smoother and reduces the noise and interference in the power supply. The color ring inductor L1 also has an energy storage characteristic, which helps to stabilize the current in the circuit. When the current changes, the color ring inductor L1 can store a certain amount of energy and release it when needed, thereby smoothing the change of the current and reducing the fluctuation of the current.

[0054] The filter circuit 223 also includes capacitors C1 and C2. Capacitors C1, C2 and the color ring inductor L1 together filter the input voltage, which can more effectively filter out noise and ripples in the power supply and provide a purer and more stable DC power supply for the circuit.

[0055] The power supply circuit 20 also includes an isolated power supply circuit 23, which is electrically connected to the secondary winding 212. The induced voltage generated by the secondary winding 212 supplies power to the isolated power supply circuit 23. The isolated power supply circuit 23 can output an isolated voltage. For example, the isolated power supply circuit 23 can supply power to devices that are easily touched by human hands, such as a keypad, to prevent the risk of electric shock. Figure 4 In the illustrated embodiment, the isolated power supply circuit 23 is used to output a +12V DC voltage. The isolated power supply circuit 23 includes a diode D5 and a capacitor C3. The diode D5 is a unidirectional diode and is used for half-wave rectification. The capacitor C3 is used for filtering. The isolated power supply circuit 23 also includes a discharge resistor R1 for circuit discharge. In some embodiments, the isolated power supply circuit 23 is used to output an isolated voltage, which can provide electrical isolation between the power supply and the power load, thereby improving the safety of the circuit.

[0056] The transformer 21 also includes an auxiliary winding 213 coupled to the primary winding 211. The power supply circuit 20 also includes a non-isolated power supply circuit 24, which is electrically connected to the auxiliary winding 213. The auxiliary winding 213 is used to supply power to the non-isolated power supply circuit 24. The non-isolated power supply circuit 24 is used to output a non-isolated voltage, for example, it can be connected to a thyristor for load driving. The voltage output by the non-isolated power supply circuit 24 and the isolated power supply circuit 23 can be the same or different. In some embodiments, the non-isolated power supply circuit 24 is used to output a non-isolated voltage and is connected to the auxiliary winding 213, which can save space.

[0057] The power supply circuit 20 also includes a switching power supply U101, which is electrically connected between the first power input terminal L and the primary winding 211, and the switching power supply U101 is electrically connected to a non-isolated power supply circuit 24, and the non-isolated power supply circuit 24 is used to power the switching power supply U101. The switching power supply U101 can quickly adjust the output voltage and current according to actual needs to meet the working requirements of different loads. In some embodiments, the switching power supply U101 can efficiently adjust the output voltage of the non-isolated power supply circuit 24.

[0058] The power supply circuit 20 also includes a controller 26 and a voltage detection circuit 25. The voltage detection circuit includes a diode D6, a first capacitor C11, a second capacitor C12, a first resistor R11, a second resistor R12, a third resistor R13, a first power supply terminal VDD1 and a first ground terminal GND1. The cathode of the diode D6 is connected to the secondary winding 212, and the diode D6, the first resistor R11, and the first capacitor C11 are connected in series between the secondary winding 212 and the first ground terminal GND1. The third resistor R13, the second resistor R12, and the first capacitor C11 are connected in series between the first power supply terminal VDD1 and the first ground terminal GND1, and the second capacitor C12 and the third resistor R13 are connected in parallel. The controller 26 includes a voltage detection port V_AD, which is connected between the second resistor R12 and the third resistor R13. The second resistor R12 and the third resistor R13 divide the voltage from the first power supply terminal VDD1 to the voltage detection port V_AD. The first resistor R11 and the first capacitor C11 are used for filtering. The diode D6 limits the current flow of the voltage detection circuit 25. When the input voltage changes, the voltage detection port V_AD changes approximately linearly with the change of the input voltage. In some embodiments, the voltage detection circuit 25 can detect the voltage change of the power supply circuit 20, so that the controller 26 can obtain the output voltage of the power supply circuit 20 in time.

[0059] The power supply circuit 20 also includes a zero-crossing detection circuit 27. The controller 26 includes a zero-crossing detection port ZERO. The zero-crossing detection circuit 27 includes a photocoupler U103, a second power supply terminal VDD2 and a second ground terminal GND2. The photocoupler U103 includes a first input terminal and a second input terminal. The first input terminal is connected between the positive temperature coefficient thermistor 221 and the rectifier circuit 222. The second input terminal is connected to the second power supply input terminal N. The output terminal of the photocoupler U103 is connected to the second power supply terminal N and the zero-crossing detection port ZERO. The photocoupler U103 transmits information through an optical signal, thereby preventing a direct electrical connection between the input terminal and the output terminal, and improving the safety of the circuit. The first input terminal of the photocoupler U103 can detect the change of the AC power supply. When the voltage of the AC power supply passes through the zero point, the photocoupler U103 generates a zero-crossing signal and transmits it to the zero-crossing detection port ZERO through the output terminal. The controller 26 can accurately control the working state of the power supply circuit 20 according to the received zero-crossing signal. For example, the switching of the switch is triggered at each zero point. In some embodiments, the zero-crossing detection circuit 27 can detect the zero-crossing point of the power supply circuit 20 , so that the controller 26 can respond according to the change of the power supply circuit 20 .

Claims

1. A power supply circuit, applied to a food processor, characterized in that: include: a first power input terminal and a second power input terminal; A transformer, comprising a primary winding and a secondary winding, wherein the primary winding is connected to the first power input terminal and the second power input terminal; and The filter and rectifier circuit comprises a positive temperature coefficient thermistor, a rectifier circuit and a filter circuit which are connected in series between the first power input terminal and the primary winding.

2. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes an isolation power supply circuit electrically connected to the secondary winding.

3. The power supply circuit according to claim 1, characterized in that: The transformer further includes an auxiliary winding coupled to the primary winding, and the power supply circuit further includes a non-isolated power supply circuit electrically connected to the auxiliary winding.

4. The power supply circuit according to claim 3, characterized in that: The power supply circuit also includes a switching power supply electrically connected between the first power input terminal and the primary winding, and the switching power supply is electrically connected to the non-isolated power supply circuit, and the non-isolated power supply circuit is used to power the switching power supply.

5. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes a controller and a voltage detection circuit; The voltage detection circuit includes a diode, a first capacitor, a second capacitor, a first resistor, a second resistor, a third resistor, a first power supply terminal and a first ground terminal; the cathode of the diode is connected to the secondary winding, the diode, the first resistor, and the first capacitor are connected in series between the secondary winding and the first ground terminal in sequence, the third resistor, the second resistor, and the first capacitor are connected in series between the first power supply terminal and the first ground terminal in sequence, and the second capacitor and the third resistor are connected in parallel; The controller includes a voltage detection port connected between the second resistor and the third resistor.

6. The power supply circuit according to claim 1, characterized in that: The power supply circuit also includes a controller and a zero-crossing detection circuit, and the controller includes a zero-crossing detection port; The zero-crossing detection circuit includes a photoelectric coupler, a second power supply terminal and a second ground terminal. The photoelectric coupler includes a first input terminal and a second input terminal. The first input terminal is connected between the positive temperature coefficient thermistor and the rectifier circuit, and the second input terminal is connected to the second power supply input terminal. The output terminal of the photoelectric coupler is connected to the second power supply terminal and the zero-crossing detection port.

7. The power supply circuit according to claim 1, characterized in that: The rectifier circuit includes a first diode and a second diode, the anode of the first diode is connected to the first power input terminal, the anode of the second diode is connected to the second power input terminal, and the cathodes of the first diode and the second diode are both connected to the filter circuit.

8. The power supply circuit according to claim 7, characterized in that: The rectifier circuit also includes a third diode and a fourth diode, the cathode of the third diode is connected to the first power input terminal, the cathode of the fourth diode is connected to the second power input terminal, and the anodes of the third diode and the fourth diode are both grounded.

9. The power supply circuit according to claim 1, characterized in that: The filter circuit includes a color ring inductor.

10. A food processor, characterized in that: include: load; A driving circuit connected to the load and used to drive the load; The power supply circuit according to any one of claims 1 to 9, connected to the drive circuit, is used to supply power to the drive circuit.

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