CN210183239U

CN210183239U - Power supply circuit and induction cooker

Info

Publication number: CN210183239U
Application number: CN201920847695.5U
Authority: CN
Inventors: Lirong Zhao; 赵礼荣; Xueyu Liu; 刘学宇
Original assignee: Zhejiang Shaoxing Supor Domestic Electrical Appliance Co Ltd
Current assignee: Zhejiang Shaoxing Supor Domestic Electrical Appliance Co Ltd
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2020-03-24
Anticipated expiration: 2029-06-06

Abstract

The embodiment of the utility model provides a power supply circuit and electromagnetism stove, this power supply circuit includes switching power supply (10), display panel (20), mainboard chip (30), switching circuit (40) and step-down circuit (50); the switching power supply (10) is respectively connected with the display panel (20) and the switching circuit (40); the switch circuit (40) is also connected with the voltage reduction circuit (50) and the display panel (20), and the voltage reduction circuit (50) is also connected with the mainboard chip (30); the display panel (20) is used for sending a first instruction to the switch circuit (40) to turn off the switch circuit (40) when in standby and sending a second instruction to the switch circuit (40) to turn on the switch circuit (40) after being turned on. The utility model discloses can reduce standby power consumption.

Description

Power supply circuit and induction cooker

Technical Field

The embodiment of the utility model provides a relate to household electrical appliances technical field, especially relate to a power supply circuit and electromagnetism stove.

Background

The induction cooker is a common household appliance for heating, and comprises a main board chip and a display panel, wherein in some scenes, isolation between the main board chip and the display panel needs to be set to prevent dangers such as electric leakage and the like, for example, a cooker arranged on the induction cooker can be electrically connected with the induction cooker.

After the motherboard chip and the display panel are isolated, power needs to be supplied to the motherboard chip and the display panel, respectively. The voltage required by the motherboard chip is usually less than the output voltage of the power supply, and therefore, the power supply needs to perform voltage reduction processing when supplying power to the motherboard chip. In the prior art, a voltage reduction circuit is generally disposed between a power supply and a motherboard chip to reduce the voltage output to the motherboard chip. However, when the induction cooker is in standby operation, the voltage reduction circuit and the like need to consume much power, which results in high standby power consumption.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a power supply circuit and electromagnetism stove to reduce stand-by power consumption.

In a first aspect, the present invention provides a power supply circuit, including: the display panel comprises a switching power supply, a display panel, a mainboard chip, a switching circuit and a voltage reduction circuit; wherein

The switch power supply is respectively connected with the display panel and the switch circuit;

the switch circuit is also connected with the voltage reduction circuit and the display panel, and the voltage reduction circuit is also connected with the mainboard chip;

the display panel is used for sending a first instruction to the switch circuit to disconnect the switch circuit when in standby and sending a second instruction to the switch circuit to connect the switch circuit after being started.

The utility model provides a power supply circuit, which comprises a switching power supply, a display panel, a mainboard chip, a switching circuit and a voltage reduction circuit; wherein, the switch power supply is respectively connected with the display panel and the switch circuit; the switch circuit is also connected with the voltage reduction circuit and the display panel, and the voltage reduction circuit is also connected with the mainboard chip; the display panel is used for sending a first instruction to the switch circuit to disconnect the switch circuit when in standby, so that the voltage reduction circuit and the mainboard chip are not electrified, and the standby power consumption is reduced.

In one possible implementation, the switching circuit includes an optocoupler chip IC4 and a transistor Q7, where the optocoupler chip IC4 and the transistor Q7 are connected to the output terminal of the transistor

The optocoupler chip IC4 is respectively connected with the display panel and the triode Q7, and the triode Q7 is respectively connected with the switching power supply and the voltage reduction circuit;

the display panel is specifically configured to send a first instruction to the optocoupler chip IC4 to turn off the transistor Q7 when in standby, and send a second instruction to the optocoupler chip IC4 to turn on the transistor Q7 after the display panel is turned on.

This switch circuit 40 not only includes triode Q7 that has the break-make function, still includes opto-coupler chip IC4, and this opto-coupler chip IC4 can realize that the display panel is kept apart with the opto-coupler of mainboard chip, when triode Q7 switches on, can avoid electric leakage, communication interference scheduling problem.

In one possible implementation manner, the transistor Q7 is a PNP-type transistor, and the optocoupler chip IC4 includes a photodiode and a phototransistor;

the anode of the photodiode is connected with the switching power supply, and the cathode of the photodiode is connected with the display panel;

the emitter of the phototriode is grounded, the collector of the phototriode is connected with the base of the PNP type triode Q7, the emitter of the PNP type triode Q7 is connected with the switching power supply, and the collector of the PNP type triode Q7 is connected with the voltage reduction circuit (50);

the display panel (20) is specifically used for sending a high level to the optical coupler chip IC4 to turn off the PNP type triode Q7 when in standby, and sending a low level to the optical coupler chip IC4 to turn on the PNP type triode Q7 after being turned on.

This embodiment is the PNP type triode through triode Q7, and opto-coupler chip IC4 includes photodiode and phototriode, only needs control opto-coupler chip IC4 output to keep the high level, just can guarantee that PNP type triode Q7 cuts to, and control opto-coupler chip IC4 output keeps the low level, just can guarantee PNP type triode Q7 saturation conduction, and not only circuit structure is simple, and control mode is simple still, easily realizes.

In one possible implementation, the power supply circuit further includes a voltage regulation chip IC5 and a filter capacitor;

the switching circuit further comprises a discharge diode D120, the anode of the discharge diode D120 is connected with the step-down circuit, and the cathode of the discharge diode D120 is connected with the emitter of the PNP triode Q7;

the voltage stabilizing chip IC5 is respectively connected with the voltage reducing circuit and the filter capacitor, and the filter capacitor is also connected with the mainboard chip.

The voltage stabilizing chip IC5 is used for voltage stabilization, the filter capacitor is used for filtering, in a standby state, when the PNP transistor Q7 is turned off, the filter capacitor C129 and the filter capacitor C118 discharge, in order to avoid the filter capacitor discharging to damage the PNP transistor Q7, the discharging diode D120 is added in the present embodiment, and the discharging diode D120 is used for discharging, so that the influence of the filter capacitor discharging on the PNP transistor Q7 is avoided.

In one possible implementation, the power supply circuit further includes a fan disposed upstream of the switching circuit and an IGBT drive circuit disposed downstream of the switching circuit.

The IGBT driving circuit 80 is disposed downstream of the switching circuit 40, whereby when the switching circuit 40 is turned off, the IGBT driving circuit is also unpowered, standby power consumption can be further reduced, and in addition, since the IGBT driving circuit 80 is not operated, it is possible to avoid damage to the IGBT circuit caused by the IGBT driving circuit turning on the IGBT by mistake during power-on.

In a possible implementation manner, the power circuit further includes a rectification filtering voltage stabilizing circuit, and the rectification filtering voltage stabilizing circuit is respectively connected with the switching power supply and the display panel.

The voltage stabilizing circuit is rectified, filtered and stabilized, so that stable voltage is provided for the display panel.

In a possible implementation manner, the power circuit further includes an isolation circuit, and the isolation circuit is connected to the display panel and the motherboard chip respectively. The isolation circuit can prevent communication interference between the display panel and the main board chip.

In one possible implementation, the switching power supply includes a transformer T101, the transformer T101 including a primary winding, a first secondary winding, and a second secondary winding;

the first secondary winding is connected with the switch circuit, and the second secondary winding is connected with the display panel.

Two paths of power supply can be realized through one primary winding and two secondary windings, one secondary winding supplies power to the fan, the IGBT driving circuit and the main board chip, the other secondary winding supplies power to the display board, and the structure is simple and easy to realize.

In one possible implementation manner, the switching power supply is a BUCK switching power supply, the switching power supply includes a power chip IC101 and a transformer T101, and the transformer T101 includes a primary winding and a secondary winding;

the primary winding is respectively connected with the power chip IC101 and the switch circuit; the secondary winding is connected to the display panel.

In the embodiment, the power is supplied to the main board chip and the display panel simultaneously only by the primary winding and the secondary winding of the two windings through the BUCK switch power supply, so that the number of the windings and the cost are saved.

In a second aspect, embodiments of the present application provide an induction cooking appliance including a power supply circuit as described in the first aspect or in various possible designs of the first aspect.

The utility model provides an electromagnetic oven, which comprises a power circuit, wherein the power circuit comprises a switch power supply, a display panel, a mainboard chip, a switch circuit and a voltage reduction circuit; the display panel is used for sending a first instruction to the switch circuit to disconnect the switch circuit when in standby, so that the voltage reduction circuit and the mainboard chip are not electrified, and the standby power consumption of the induction cooker is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a first schematic structural diagram of a switching power supply provided by the present invention;

fig. 2 is a schematic structural diagram of a switching power supply according to the present invention;

fig. 3 is a third schematic structural diagram of the switching power supply provided by the present invention;

fig. 4 is a schematic structural diagram of a switching power supply according to the present invention.

Description of reference numerals:

10-a switching power supply;

20-a display panel;

30-a motherboard chip;

40-a switching circuit;

50-a voltage reduction circuit;

60-an isolation circuit;

70-a fan;

80-IGBT drive circuit;

and 90-rectifying, filtering and voltage-stabilizing circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The induction cooker is a common household appliance for heating, and when the induction cooker works, high-frequency alternating current is utilized to pass through the coil panel so as to enable the bottom of a pot placed on the induction cooker to generate eddy current, so that the pot arranged on the induction cooker is heated.

Specifically, a main board chip and a display panel are usually arranged in the electromagnetic oven, the main board chip is used for realizing a specific heating function, the display panel is used for displaying related functions of the electromagnetic oven, and the like, wherein the main board chip and the display panel are both devices arranged on the existing electromagnetic oven, and details are not repeated here.

After the motherboard chip and the display panel are isolated, power needs to be supplied to the motherboard chip and the display panel, respectively. The voltage required by the motherboard chip is typically less than the output voltage of the power supply. Therefore, when the switching power supply supplies power to the motherboard chip, a voltage reduction circuit is usually arranged between the switching power supply and the motherboard chip to reduce the voltage supplied to the motherboard chip.

In order to reduce the power consumption of the induction cooker in the standby state, the present embodiment provides a power supply circuit, in which a switch circuit is added to turn off the voltage reduction circuit in the standby state, so as to reduce the power consumption of the induction cooker. The power supply circuit provided in this embodiment can be applied not only to an electromagnetic oven but also to any household appliance that is heated by electromagnetic waves and is provided with a display panel, and the present embodiment does not particularly limit the type of the household appliance. In the present embodiment, for convenience of description, an induction cooker is taken as an example for explanation.

Fig. 1 is a schematic structural diagram of a switching power supply, as shown in fig. 1, the power supply circuit includes: a switching power supply 10, a display panel 20, a main board chip 30, a switching circuit 40, and a voltage step-down circuit 50; wherein, the switching power supply 10 is respectively connected with the display panel 20 and the switching circuit 40; the switch circuit 40 is further connected with the voltage reduction circuit 50 and the display panel 20, and the voltage reduction circuit 50 is further connected with the main board chip 30; the display panel 20 is used to send a first instruction to the switch circuit 40 to turn off the switch circuit 40 during standby, and send a second instruction to the switch circuit 40 to turn on the switch circuit 40 after power-on.

In the present embodiment, the switching power supply 10 can supply power to the display panel 20 and the main board chip 30. When the main board chip 30 works normally, the control process of the induction cooker can be completed. The display panel 20 is mainly responsible for displaying and receiving various instructions of a user, and the display panel 20 may be a touch type display panel, and the user sends various instructions to the display panel by touching keys. The voltage reducing circuit 50 may include a voltage reducing resistor, and the like, and the number and the connection manner of the resistors included in the voltage reducing circuit 50 are not particularly limited in this embodiment as long as the voltage reducing and stabilizing functions can be achieved.

The power circuit may further include a fan 70 and an Insulated Gate Bipolar Transistor (IGBT) driving circuit 80, wherein when the main board chip 30 operates, the fan 70 and the IGBT driving circuit 80 may be controlled to operate, and the IGBT driving circuit may control on/off of the IGBT so that the resonant circuit resonates, thereby performing electromagnetic heating.

The power circuit may further include a rectifying and filtering voltage stabilizing circuit 90, and the rectifying and filtering voltage stabilizing circuit 90 is respectively connected to the switching power supply 10 and the display panel 20. The switching power supply 10 outputs a voltage of about 9V to the rectifying, filtering and voltage stabilizing circuit 90, and the voltage is processed by the rectifying, filtering and voltage stabilizing circuit 90 to be a 5V operating voltage of the display panel 20, and the display panel 20 can operate at the 5V voltage during standby and power-on.

Optionally, an isolation circuit 60 is further disposed between the motherboard chip 30 and the display panel 20, the isolation circuit 60 may prevent communication interference and the like, and the isolation circuit 60 may be, for example, an isolation communication circuit. The present embodiment does not particularly limit the implementation of the isolation circuit 60.

In the specific implementation process, after the power plug of the induction cooker is connected to the mains supply, the induction cooker is powered on, and the switching power supply 10 is in a standby state at the moment. When the display panel 20 does not receive the power-on command, the display panel 20 sends a first command to the switch circuit 40, and the first command is used for controlling the switch circuit 40 to be turned off. When the switching circuit 40 is turned off, the step-down circuit 50 and the main board chip 30 stop operating, thereby reducing standby power consumption.

Further, in the present embodiment, the IGBT driving circuit 80 may be disposed downstream of the switching circuit 40, and thus, when the switching circuit 40 is turned off, the IGBT driving circuit is not powered, and the standby power consumption may be further reduced, and further, since the IGBT driving circuit 80 is not operated, it may be avoided that the IGBT driving circuit is turned on by mistake during power-on, which may cause damage to the IGBT circuit.

When the display panel 20 receives the power-on command, the display panel 20 sends a second command to the switch circuit 40, and the second command is used to control the switch circuit 40 to be turned on. When the switching circuit 40 is turned on, the voltage step-down circuit 50 and the motherboard chip 30 start to operate normally.

The switch circuit 40 may be a circuit including a transistor, a MOS transistor, a relay, or the like, for example, and transmits a level command or the like to the switch circuit 40 through the display panel 20 to control on/off of the switch circuit 40.

Fig. 2 is a schematic structural diagram of a switching power supply according to the present invention, and in this embodiment, the structure of the power supply circuit will be further described in detail. As shown in fig. 2, the switching circuit 40 includes an optocoupler chip IC4 and a transistor Q7, wherein

The optocoupler chip IC4 is respectively connected with the display panel 20 and the triode Q7, and the triode Q7 is respectively connected with the switching power supply 10 and the voltage reduction circuit 50; the display panel 20 is specifically configured to send a first command to the optocoupler chip IC4 to turn off the transistor Q7 during standby, and to send a second command to the optocoupler chip IC4 to turn on the transistor Q7 after power-on. The voltage reduction circuit 50 includes a voltage reduction resistor R150, and the voltage division function of the voltage reduction resistor R150 converts the 18V voltage into the 5V voltage to supply power to the motherboard chip 30.

In this embodiment, this switch circuit 40 not only includes triode Q7 that has the break-make function, still includes opto-coupler chip IC4, and this opto-coupler chip IC4 can realize that the opto-coupler of display panel 20 and mainboard chip 30 is kept apart, when triode Q7 switches on, can avoid electric leakage, communication interference scheduling problem.

The display panel 20 may send a level command to the optocoupler chip IC4 when in standby, the optocoupler chip IC4 sends a level command processed by the optocoupler chip IC4 to the transistor Q7, so that the transistor Q7 is turned off, the display panel 20 sends a level command to the optocoupler chip IC4 when in power on, and the optocoupler chip IC4 sends a level command processed by the optocoupler chip IC4 to the transistor Q7, so that the transistor Q7 is saturated.

In one possible implementation, the transistor Q7 is a PNP transistor, and the optocoupler chip IC4 includes a photodiode and a phototransistor.

This opto-coupler chip IC4 includes 4 pins, and wherein, pin 1 is photodiode's positive pole, and pin 2 is photodiode's negative pole, and pin 3 is the projecting pole of phototriode, and pin 4 is the collecting electrode of phototriode.

The positive pole of the photodiode is connected with the switching power supply 10, and the negative pole of the photodiode is connected with the display panel 20; the emitter of the phototriode is grounded, the collector of the phototriode is connected with the base of a PNP type triode Q7, the emitter of the PNP type triode Q7 is connected with the switching power supply 10, and the collector of the PNP type triode Q7 is connected with the step-down circuit 50.

When standby, the display panel 20 makes pin 2 of opto-coupler chip IC4 keep the high level, namely the negative pole of photodiode is the high level, and the photodiode cuts to, makes the output of opto-coupler chip IC4, namely pin 4 output also is for keeping the high level, and the base of PNP type triode Q7 is the high level this moment, and switching power supply 10 also provides the high level to the projecting pole of PNP type triode Q7, so PNP type triode Q7 cuts to step-down circuit 50 and mainboard chip 30 do not have the circular telegram. It will be appreciated by those skilled in the art that the high level of the base of the PNP transistor Q7 corresponds to VDD, for example, 18V.

When the electronic device is turned on, the display panel 20 keeps the pin 2 of the optocoupler chip IC4 at a low level, that is, the cathode of the photodiode is at a low level, the photodiode starts to work, so that the output end of the optocoupler chip IC4, that is, the output of the pin 4 is also at a low level, the base of the PNP type triode Q7 is at a low level, the switching power supply 10 provides a high level for the emitter of the PNP type triode Q7, so the PNP type triode Q7 is turned on, thereby the voltage reduction circuit 50 and the main board chip 30 are powered on and start to work normally.

The switch circuit 40 further includes a resistor R148, a resistor R5, and a resistor R50, which can, for example, perform functions of current limiting, voltage dividing, and the like, and protect the circuit, and the functions of the resistors are not described in detail in this embodiment.

In one possible implementation, as shown in fig. 2, the power supply circuit further includes a regulator chip IC5 and a filter capacitor. Optionally, the filter capacitor may include a filter capacitor C129 and a filter capacitor C118. The voltage reducing resistor R150 is used for reducing the voltage of 18V to 5V, the voltage stabilizing chip IC5 is used for stabilizing voltage, and the filter capacitor C129 and the filter capacitor C118 are used for filtering.

The switch circuit 40 further includes a discharge diode D120, wherein the anode of the discharge diode D120 is connected to the step-down resistor R150, and the cathode of the discharge diode D120 is connected to the emitter of the PNP transistor Q7; the voltage stabilizing chip IC5 is respectively connected with the voltage reducing resistor R150 and the filter capacitor, and the filter capacitor is also connected with the mainboard chip.

In a standby state, when the PNP transistor Q7 is turned off, the filter capacitor C129 and the filter capacitor C118 discharge, and in order to avoid the filter capacitor discharging to damage the PNP transistor Q7, a discharge diode D120 is added in the embodiment, and the discharge diode D120 is used for discharging, so that the influence of the filter capacitor discharging on the PNP transistor Q7 is avoided.

In one possible implementation, as shown in FIG. 2, the rectifying, filtering and voltage stabilizing circuit 90 includes a rectifying diode D117, a voltage stabilizing chip IC6, and a filter capacitor C117 and a filter capacitor C122.

The power supplied from the switching power source is rectified by the rectifying diode D117, the voltage stabilizing chip IC6 stabilizes voltage, and the smoothing capacitor C117 and the smoothing capacitor C122 perform smoothing, thereby supplying a stable voltage to the display panel 20.

Fig. 3 is a third schematic structural diagram of the switching power supply provided by the present invention, as shown in fig. 3, the switching power supply in this embodiment includes a transformer T101, where the transformer T101 includes a primary winding, a first secondary winding, and a second secondary winding; wherein the first secondary winding is connected to the switching circuit 40 and the second secondary winding is connected to the display panel 20. I.e. power is supplied to the motherboard chip 30 and the display panel 20, respectively, through two separate secondary windings.

As shown in fig. 3, the commercial power enters the primary winding, then is converted into 18V voltage through the first secondary winding, and is rectified through the rectifying diode D109 to obtain 18V dc voltage VDD, which can supply power to the

fan

70, and 5V voltage is obtained through the switching circuit 40 and the voltage reduction circuit 50 to supply power to the motherboard chip 30.

The voltage of about 9V can be obtained after the conversion of the second secondary winding, and then the voltage is converted into the voltage of 5V by the rectifying, filtering and stabilizing circuit 90 to be provided for the display panel 20.

According to the embodiment of the application, two paths of power supply can be realized through one primary winding and two secondary windings, one secondary winding supplies power to the fan, the IGBT driving circuit and the main board chip, the other secondary winding supplies power to the display panel, and the structure is simple and easy to realize.

Fig. 4 is a fourth schematic structural diagram of the switching power supply provided by the present invention, as shown in fig. 4, the switching power supply 10 provided by this embodiment is a BUCK switching power supply, the switching power supply 10 includes a power chip IC101 and a transformer T101, and the transformer T101 includes a primary winding and a secondary winding; the primary winding is respectively connected with the power chip IC101 and the switch circuit 40; the secondary winding is connected to the display panel 20.

A possible implementation manner of the BUCK switching power supply is provided in this embodiment, and for implementation manners of other forms of switching power supplies, details are not described here.

In this embodiment, the switching power supply 10 may further include a rectifying diode D3, a capacitor C111, and a voltage regulation chip IC101, the rectifying diode D3 rectifies the utility power, the capacitor C111 can perform filtering, the current processed by the rectifying diode D3 and the capacitor C111 is input to the voltage regulation chip IC101, and the voltage regulation processing is performed by the voltage regulation chip IC 101. The current output by the voltage stabilization chip IC101 can be converted into 18V direct current to the transformer T101 after being filtered by the filter capacitor C119.

The primary winding of the transformer T101 is connected to a capacitor C120 and the fan 70, and the filter capacitor C120 performs a filtering process so as to supply 18V to the fan 70, and after passing through the step-down circuit 50 and the like, the voltage is reduced to 5V and supplied to the motherboard chip. The secondary winding of the transformer T101 can supply power to the display panel 20, and the voltage of about 9V provided by the secondary winding is processed by the rectifying, filtering and stabilizing circuit 90 to obtain a voltage of 5V to be provided to the display panel 20.

The switching power supply 10 further includes a diode D109, the diode D109 can prevent the filter capacitor C120 from discharging to damage the circuit, and the diode D115 can also protect the circuit.

The present embodiment also provides an induction cooker including the power supply circuit shown in fig. 1 to 4.

In a possible implementation manner, the utility model provides a be provided with the interface on the display panel of electromagnetism stove, wherein the concrete model of interface can set up according to the bayonet joint of pan, and this is not injectd to this here, and in this embodiment, the interface is used for being connected with the pan electricity, and wherein sets up the electricity and connect additional function such as can realize the anti-overflow, measure pan temperature to the usability of extension electromagnetism stove.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and not to limit the same; although embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention.

Claims

1. A power supply circuit, comprising: the display panel comprises a switching power supply (10), a display panel (20), a mainboard chip (30), a switching circuit (40) and a voltage reduction circuit (50); wherein

The switching power supply (10) is respectively connected with the display panel (20) and the switching circuit (40);

the switch circuit (40) is also connected with the voltage reduction circuit (50) and the display panel (20), and the voltage reduction circuit (50) is also connected with the mainboard chip (30);

the display panel (20) is used for sending a first instruction to the switch circuit (40) to turn off the switch circuit (40) when in standby and sending a second instruction to the switch circuit (40) to turn on the switch circuit (40) after being turned on.

2. The power supply circuit of claim 1, wherein the switching circuit (40) comprises an optocoupler chip IC4 and a transistor Q7, wherein

The optocoupler chip IC4 is respectively connected with the display panel (20) and the triode Q7, and the triode Q7 is respectively connected with the switching power supply (10) and the voltage reduction circuit (50);

the display panel (20) is specifically used for sending a first instruction to the optical coupler chip IC4 to enable the triode Q7 to be switched off in a standby state, and sending a second instruction to the optical coupler chip IC4 to enable the triode Q7 to be switched on after the display panel is switched on.

3. The power supply circuit according to claim 2, wherein the transistor Q7 is a PNP-type transistor, and the optocoupler chip IC4 includes a photodiode and a phototransistor;

the anode of the photodiode is connected with the switching power supply (10), and the cathode of the photodiode is connected with the display panel (20);

the emitter of the phototriode is grounded, the collector of the phototriode is connected with the base of the PNP type triode Q7, the emitter of the PNP type triode Q7 is connected with the switching power supply (10), and the collector of the PNP type triode Q7 is connected with the voltage reduction circuit (50);

4. The power supply circuit according to claim 3, wherein the power supply circuit further comprises a voltage regulator chip IC5 and a filter capacitor;

the switch circuit (40) further comprises a discharge diode D120, the anode of the discharge diode D120 is connected with the step-down circuit (50), and the cathode of the discharge diode D120 is connected with the emitter of the PNP type triode Q7;

the voltage stabilizing chip IC5 is respectively connected with the voltage reducing circuit (50) and the filter capacitor, and the filter capacitor is also connected with the mainboard chip.

5. The power supply circuit according to claim 1, further comprising a fan (70) and an IGBT driver circuit (80), the fan (70) being disposed upstream of the switch circuit (40), the IGBT driver circuit (80) being disposed downstream of the switch circuit (40).

6. The power supply circuit according to claim 1, further comprising a rectifying and filtering voltage regulator circuit (90), wherein the rectifying and filtering voltage regulator circuit (90) is connected to the switching power supply (10) and the display panel (20), respectively.

7. The power supply circuit according to any one of claims 1 to 6, further comprising an isolation circuit (60), wherein the isolation circuit (60) is connected to the display panel (20) and the motherboard chip (30), respectively.

8. A power supply circuit according to any one of claims 1-6, characterized in that the switching power supply (10) comprises a transformer T101, the transformer T101 comprising a primary winding, a first secondary winding and a second secondary winding;

the first secondary winding is connected to the switching circuit (40), and the second secondary winding is connected to the display panel (20).

9. The power supply circuit according to any one of claims 1 to 6, wherein the switching power supply (10) is a BUCK switching power supply, the switching power supply (10) comprises a power chip IC101 and a transformer T101, the transformer T101 comprises a primary winding and a secondary winding;

the primary winding is respectively connected with the power chip IC101 and the switch circuit (40); the secondary winding is connected to the display panel (20).

10. An induction hob, characterized in, that the induction hob comprises a power supply circuit according to any one of the claims 1 to 9.