A power supply circuit for an insulated bag and an insulated bag

Abstract

The application discloses a power supply circuit for a thermal insulation bag and a thermal insulation bag. The power supply circuit is used for providing power for a heating source of the thermal insulation bag when an external alternating current power supply or a direct current power supply is connected, and comprises an alternating current power supply circuit and a direct current power supply circuit. The heating source of the thermal insulation bag comprises soft rope type electric heating elements of first heating electric heating wires, second heating electric heating wires and third heating electric heating wires. The alternating current power supply circuit is used for converting the external alternating current power supply into first direct current and then outputting the first direct current to the first heating electric heating wires. The direct current power supply circuit is used for outputting an external direct current first power supply or a direct current second power supply to the corresponding connected second heating electric heating wires and third heating electric heating wires. Since the first, second and third heating electric heating wires have the same thermal energy output power, the thermal insulation bag can support different external power supplies and can also ensure the same thermal insulation effect under the condition of connecting different power supplies.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric heating, in particular to a power supply circuit for a thermal insulation bag and a thermal insulation bag. BACKGROUND

[0002] In real life, people always need to use thermal insulation bags to keep warm food warm, but the heat of the food will still disappear over time, and finally become cold, the difference between good and bad thermal insulation bags is only the length of the time that can be kept warm, and it is impossible to keep the food warm all the time, if the food becomes cold due to long storage time, it will seriously affect the taste of the food, and some people with gastrointestinal problems cannot eat cold food and can only choose to discard, resulting in food waste. If you choose to reheat the food, you need to find an external heating device (such as a microwave oven), and once you cannot find it, you cannot reheat the food, and the heating conditions are greatly limited. In order to solve the above problems, the market has appeared an electric heating type thermal insulation bag, which sets a heating layer in the bottom, top and / or four layers of the thermal insulation bag to convert the electric energy of the external power supply into heat energy to provide a heat source for the thermal insulation bag, however, such products only support one type of external power supply (mains or DC power adapter), and the original intention of using the thermal insulation bag is to be portable, and the single type of external power supply greatly limits the application and popularization of the electric heating type thermal insulation bag. Therefore, it is necessary to design an electric heating type thermal insulation bag supporting multiple types of external power supply. SUMMARY

[0003] The technical problem solved by the present application is to adapt the thermal insulation bag to multiple external power supplies.

[0004] According to a first aspect, an embodiment provides a power supply circuit for providing electric energy for the heating source of the thermal insulation bag when an external AC power supply or DC power supply is connected, the power supply circuit comprising an AC power supply circuit and a DC power supply circuit; the heating source of the thermal insulation bag is a soft rope type electric heating element, and the soft rope type electric heating element comprises a first heating electric heating wire, a second heating electric heating wire and a third heating electric heating wire;

[0005] The AC power supply circuit is electrically connected with the first heating electric heating wire; the AC power supply circuit is used for converting the AC power supply into a first DC power when the AC power supply is connected, and outputting the first DC power to the first heating electric heating wire, so as to use the first DC power as the heating power of the first heating electric heating wire;

[0006] The direct current power supply circuit is electrically connected with the second heating wire and the third heating wire respectively; when the direct current power supply circuit is externally connected with the direct current power supply, the direct current power supply is output to the second heating wire or the third heating wire to provide heating power for the second heating wire or the third heating wire; wherein the externally connected direct current power supply is a direct current first power supply or a direct current second power supply, the power supply voltage of the direct current first power supply is less than the power supply voltage of the direct current second power supply; when the direct current power supply circuit is externally connected with the direct current first power supply, the direct current power supply circuit takes the direct current first power supply as the heating power supply of the second heating wire; when the direct current power supply circuit is externally connected with the direct current second power supply, the direct current power supply circuit takes the direct current second power supply as the heating power supply of the third heating wire.

[0007] When the first heating wire, the second heating wire and the third heating wire are respectively taken as the heating source of the heat preservation bag, the heat energy output power of each of them is the same.

[0008] In an embodiment, the externally connected alternating current power supply is an alternating current first power supply or an alternating current second power supply, the power supply voltage of the alternating current first power supply is greater than the power supply voltage of the alternating current second power supply.

[0009] When the alternating current power supply circuit is externally connected with the alternating current first power supply or the alternating current second power supply, the alternating current first power supply or the alternating current second power supply is converted into the first direct current and then output to the first heating wire, and the first direct current is taken as the heating power supply of the first heating wire.

[0010] In an embodiment, the alternating current power supply circuit comprises an alternating current connection circuit, a first reference voltage acquisition circuit, a first comparison circuit, a first control circuit and a first switching circuit.

[0011] The alternating current connection circuit comprises an alternating current positive connection end, an alternating current negative connection end and an alternating current output end; the alternating current positive connection end of the alternating current connection circuit is used to be connected with the positive output end of the externally connected alternating current power supply, and the alternating current negative connection end of the alternating current connection circuit is used to be connected with the negative output end of the externally connected alternating current power supply; the alternating current output end of the alternating current connection circuit is connected with the first reference voltage acquisition circuit, the first switching circuit and the first comparison circuit, and is used to output the electric energy of the externally connected alternating current power supply to the first reference voltage acquisition circuit, the first switching circuit and the first comparison circuit.

[0012] The first reference voltage acquisition circuit comprises a first AC input end and a reference voltage output end, the first AC input end of the first reference voltage acquisition circuit is connected with the AC output end of the AC connection circuit, and the reference voltage output end of the first reference voltage acquisition circuit is connected with the first comparison circuit and the first switching circuit; the first reference voltage acquisition circuit is used for converting the electric energy of the AC power supply into a first reference voltage source with a preset voltage value and a direct current, and outputting the first reference voltage source to the first comparison circuit and the first switching circuit through the reference voltage output end of the first reference voltage acquisition circuit;

[0013] The first comparison circuit comprises an AC electric energy input end, a reference power supply input end and a comparison result output end; the AC electric energy input end of the first comparison circuit is connected with the AC output end of the AC connection circuit, the reference power supply input end of the first comparison circuit is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the comparison result output end of the first comparison circuit is connected with the first control circuit; the first comparison circuit is used for converting the electric energy of the AC power supply into a first sampling voltage source with a direct current, comparing the voltage of the first sampling voltage source with the voltage of the first reference voltage source, and outputting a first result electric signal to the first control circuit according to the comparison result; when the AC power supply circuit is externally connected with the AC first power supply, the first result electric signal is a high-level signal, and when the AC power supply circuit is externally connected with the AC second power supply, the first result electric signal is a low-level signal;

[0014] The first control circuit comprises a comparison signal input end and a control signal output end; the comparison signal input end of the first control circuit is connected with the comparison result output end of the first comparison circuit, and the control signal output end of the first control circuit is connected with the first switching circuit; the first control circuit is used for outputting a pull-down signal grounded to the first switching circuit according to the first result electric signal, and grounding the control signal output end when the first result electric signal is a high-level signal, and making the control signal output end empty when the first result electric signal is a low-level signal;

[0015] The first switching circuit includes a control signal input end, a reference voltage connection end, an alternating current energy input end and a thermal energy power output end; the control signal input end of the first switching circuit is connected with the control signal output end of the first control circuit, the reference voltage connection end of the first switching circuit is connected with the reference voltage output end of the first reference voltage acquisition circuit, the alternating current energy input end of the first switching circuit is connected with the alternating current output end of the alternating current connection circuit, and the thermal energy power output end of the first switching circuit is connected with the first heating electric heating wire; the first switching circuit is used for converting the alternating current first power input by the alternating current energy input end into the first direct current when the control signal input end is grounded, and outputting the converted first direct current to the first heating electric heating wire through the thermal energy power output end; the first switching circuit is also used for converting the alternating current second power input by the alternating current energy input end into the first direct current when the control signal input end is empty, and outputting the converted first direct current to the first heating electric heating wire through the thermal energy power output end.

[0016] In an embodiment, the alternating current connection circuit further includes a fuse F1, a first indicator lamp Led1 and a first current limiting resistor R1; one end of the fuse F1 is connected with the alternating current positive connection end of the alternating current connection circuit, and the other end of the fuse F1 is connected with the alternating current output end of the alternating current connection circuit; the first indicator lamp Led1 and the first current limiting resistor R1 are connected in series, one end after the series connection is connected with the alternating current negative connection end of the alternating current connection circuit, and the other end after the series connection is connected with the alternating current output end of the alternating current connection circuit;

[0017] And / or, the first reference voltage acquisition circuit further includes a first capacitor C11, a second capacitor C12, a third capacitor C13, a first diode D11, a second diode D12 and a first resistor R11; one end of the first capacitor C11 is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the other end is grounded; one end of the second capacitor C12 is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the other end is grounded; the positive electrode of the first diode D11 is connected with the negative electrode of the second diode D12, the negative electrode of the first diode D11 is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the positive electrode of the second diode D12 is grounded; the third capacitor C13 and the first resistor R11 are connected in series, one end after the series connection is connected with the negative electrode of the second diode D12, and the other end after the series connection is connected with the first alternating current input end of the first reference voltage acquisition circuit;

[0018] And / or, the first comparison circuit further comprises a third diode D21, a second resistor R21, a third resistor R22, a fourth resistor R23, a fifth resistor R24, a sixth resistor R25 and a first comparator T1; the third diode D21, the second resistor R21 and the third resistor R22 are connected in series, one end of the series connection is connected with the AC power input end of the first comparison circuit, the other end of the series connection is connected with the positive input end of the first comparator T1; one end of the fourth resistor R23 is grounded, the other end is connected with the positive input end of the first comparator T1; one end of the fifth resistor R24 is connected with the reference power input end of the first comparison circuit, the other end is connected with the negative input end of the first comparator T1; one end of the sixth resistor R25 is grounded, the other end is connected with the negative input end of the first comparator T1; the output end of the first comparator T1 is connected with the comparison result output end of the first comparison circuit;

[0019] And / or, the first control circuit further comprises a seventh resistor R31, an eighth resistor R32 and a triode Q1; one end of the seventh resistor R31 is grounded, the other end is connected with the comparison signal input end of the first control circuit; one end of the eighth resistor R32 is connected with the comparison signal input end of the first control circuit, the other end is connected with the base of the triode Q1; the emitter of the triode Q1 is grounded, the collector of the triode Q1 is connected with the control signal output end of the first control circuit;

[0020] And / or, the first switching circuit further comprises a ninth resistor R41, a fourth diode D41, a fifth diode D42 and a first electronic switch U1; one end of the ninth resistor R41 is connected with the reference voltage connection end of the first switching circuit, the other end is connected with the first electronic switch U1; the fifth diode D42 is connected with the first electronic switch U1 at both ends; the positive connection end of the fourth diode D41 is connected with the first electronic switch U1 and the AC power input end of the first switching circuit, the negative connection end of the fourth diode D41 is connected with the first heating electric heating wire and the first electronic switch U1; the first electronic switch U1 is used for outputting the AC first power input by the AC power input end to the first heating electric heating wire through the fourth diode D41 when the control signal input end is grounded; the first switching circuit is further used for outputting the AC second power input by the AC power input end to the first heating electric heating wire through the first electronic switch U1 when the control signal input end is empty.

[0021] In an embodiment, the direct current power supply circuit comprises a direct current connection circuit, a second reference voltage acquisition circuit, a sampling circuit, a second comparison circuit and a third comparison circuit;

[0022] The direct current connection circuit comprises a direct current positive connection end, a direct current negative connection end and a direct current output end; the direct current positive connection end of the direct current connection circuit is used for connecting with the positive output end of the external direct current power supply, the direct current negative connection end of the direct current connection circuit is used for connecting with the negative output end of the external direct current power supply, and the direct current output end of the direct current connection circuit is connected with the second reference voltage acquisition circuit, the sampling circuit, the second comparison circuit and the third comparison circuit, and is used for outputting the direct current power supply;

[0023] The second reference voltage acquisition circuit comprises a power input end and a reference power output end, the power input end of the second reference voltage acquisition circuit is connected with the direct current output end of the direct current connection circuit, and the reference power output end of the second reference voltage acquisition circuit is connected with the sampling circuit, the second comparison circuit and the third comparison circuit; the second reference voltage acquisition circuit is used for converting the direct current power supply into a second reference voltage source with a preset voltage value, and outputting the second reference voltage source through the reference power output end;

[0024] The sampling circuit comprises an input first connection end, an input second connection end, an output first connection end, an output second connection end, an output third connection end and an output fourth connection end; the input first connection end of the sampling circuit is connected with the direct current output end of the direct current connection circuit, the input second connection end of the sampling circuit is connected with the reference power output end of the second reference voltage acquisition circuit, the output first connection end and the output second connection end of the sampling circuit are connected with the second comparison circuit, and the output third connection end and the output fourth connection end of the sampling circuit are connected with the third comparison circuit; the sampling circuit is used for respectively performing voltage division sampling on the second reference voltage source and the direct current power supply, and outputting the results of the two voltage division samplings to the second comparison circuit through the output first connection end and the output second connection end, and then outputting the results to the third comparison circuit through the output third connection end and the output fourth connection end;

[0025] The circuit structure of the second comparison circuit and the third comparison circuit is same, and each includes a first comparison input end, a second comparison input end and a DC power output end; the first comparison input end and the second comparison input end of the second comparison circuit are connected with the output first connection end and the output second connection end of the sampling circuit respectively, the first comparison input end and the second comparison input end of the third comparison circuit are connected with the output third connection end and the output fourth connection end of the sampling circuit respectively, the DC power output end of the second comparison circuit is connected with the second heating electric heating wire, and the DC power output end of the third comparison circuit is connected with the third heating electric heating wire; the second comparison circuit is used for outputting the DC first power to the second heating electric heating wire when the DC power is the DC first power, so as to take the DC first power as the heating power of the second heating electric heating wire; the third comparison circuit is used for outputting the DC second power to the third heating electric heating wire when the DC power is the DC second power, so as to take the DC second power as the heating power of the third heating electric heating wire.

[0026] In an embodiment, the second reference voltage acquisition circuit further comprises a DC conversion circuit Y1, a fourth capacitor C61, a fifth capacitor C62, a sixth capacitor C63 and a sixth diode D61; the positive electrode of the sixth diode D61 is connected with the power input end of the second reference voltage acquisition circuit, and the negative electrode of the sixth diode D61 is connected with the input end of the DC conversion circuit Y1; the output end of the DC conversion circuit Y1 is connected with the reference power output end of the second reference voltage acquisition circuit;

[0027] One end of the fourth capacitor C61 is connected with the reference power output end of the second reference voltage acquisition circuit, and the other end is grounded;

[0028] One end of the fifth capacitor C62 is connected with the reference power output end of the second reference voltage acquisition circuit, and the other end is grounded;

[0029] One end of the sixth capacitor C63 is connected with the input end of the DC conversion circuit Y1, and the other end is grounded;

[0030] And / or, the sampling circuit further comprises a tenth resistor R71, an eleventh resistor R72, a twelfth resistor R73, a thirteenth resistor R74 and a seventh diode D71; the seventh diode D71 and the tenth resistor R71 are connected in series, one end of the series connection is connected with the input first connection end of the sampling circuit, the other end of the series connection is connected with the output second connection end and the output third connection end of the sampling circuit; one end of the eleventh resistor R72 is connected with the input second connection end of the sampling circuit, the other end is grounded; one end of the twelfth resistor R73 is connected with the input second connection end of the sampling circuit, the other end is connected with the output first connection end and the output fourth connection end of the sampling circuit; one end of the thirteenth resistor R74 is connected with the output first connection end of the sampling circuit, the other end is grounded.

[0031] In an embodiment, the second reference voltage acquisition circuit further comprises a second indicator lamp Led2 and a second current limiting resistor R2, the second indicator lamp Led2 and the second current limiting resistor R2 are connected in series, one end of the series connection is connected with the reference power output end of the second reference voltage acquisition circuit, the other end is grounded.

[0032] In an embodiment, the second comparison circuit further comprises a second comparator T2, a fourteenth resistor R81, a fifteenth resistor R82, a sixteenth resistor R83, an eighth diode D81, a second electronic switch U2 and a second triode Q2.

[0033] One end of the fourteenth resistor R81 is connected with the output end of the second comparator T2, the other end is connected with the base of the second triode Q2; one end of the fifteenth resistor R82 is connected with the base of the second triode Q2, the other end is grounded; the emitter of the second triode Q2 is grounded, the collector of the second triode Q2 is connected with the second electronic switch U2; the two ends of the eighth diode D81 are connected with the second electronic switch U2; one end of the sixteenth resistor R83 is connected with the second electronic switch U2, the other end is connected with the reference power output end of the second reference voltage acquisition circuit; the second electronic switch U2 is also connected with the direct current output end of the direct current connection circuit;

[0034] And / or, the third comparison circuit further comprises a third comparator T3, a seventeenth resistor 91, an eighteenth resistor R92, a nineteenth resistor R93, a ninth diode D91, a third electronic switch U3 and a third triode Q3.

[0035] One end of the seventeenth resistor R91 is connected with the output terminal of the third comparator T3, and the other end is connected with the base of the third triode Q3; one end of the eighteenth resistor R92 is connected with the base of the third triode Q3, and the other end is grounded; the emitter of the third triode Q3 is grounded, the collector of the third triode Q3 is connected with the third electronic switch U3; the two ends of the ninth diode D91 are connected with the third electronic switch U3; one end of the nineteenth resistor R93 is connected with the third electronic switch U3, and the other end is connected with the reference power output terminal of the second reference voltage acquisition circuit; the third electronic switch U3 is also connected with the direct current output terminal of the direct current connection circuit.

[0036] According to the second aspect, in an embodiment, a heat preservation bag is provided, comprising the power supply circuit as described in the first aspect.

[0037] In an embodiment, the heat preservation bag further comprises a soft rope type electric heating element, the soft rope type electric heating element is a three-core heating wire, the three-core heating wire comprises an insulating protective wire sheath and a first heating electric heating wire, a second heating electric heating wire and a third heating electric heating wire which are respectively insulated and arranged in the insulating protective wire sheath and are wound around each other.

[0038] According to the heat preservation bag described in the above embodiment, since the first, second and third heating electric heating wires for the heating source have the same heat energy output power, the heat preservation bag can support different external power supplies and can also ensure the same heat preservation effect under the condition of different external power supplies. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of the soft rope type electric heating element in an embodiment;

[0040] Figure 2 It is a structural connection schematic diagram of the power supply circuit in an embodiment;

[0041] Figure 3 It is a circuit connection schematic diagram of the power supply circuit in an embodiment;

[0042] Figure 4 It is a circuit connection schematic diagram of the power supply circuit in another embodiment. DETAILED DESCRIPTION

[0043] The application will be described in further detail below with specific reference being made to the drawings. Like elements in different embodiments are denoted by like reference numerals. In the following description, numerous specific details are described to provide a thorough understanding of the application. However, it will be apparent to one skilled in the art that the application can be practiced without these specific details. In other instances, well-known structures have not been described in detail in order to avoid obscuring the application. In the following description, the terms "couple" and "coupled" refer to an electrical connection, whether direct and / or indirect, that is created by having one or more wires, cables, and / or printed materials connect one device / component / subsystem / piece of code / droplet of fluid to another device / component / subsystem / piece of code / droplet of fluid.

[0044] In addition, features from one embodiment can be combined with features of another embodiment. Moreover, the steps recited in any of the methods can be ordered in any suitable way. Accordingly, embodiments of the application have been disclosed by way of examples only. Numerous modifications and alterations have been disclosed and others will occur to those skilled in the art once given the teachings herein. Therefore, the applications are not intended to be limited to the embodiments described. Rather, it is intended to cover all alternatives, modifications, and equivalents of the applications, including those which are currently or later become the equivalents thereof. In addition, while the application is susceptible to various modifications and alternative forms, specific embodiments and methods thereof have been described and illustrated by way of example in this specification. The intention is that the application be construed as not being limited to the particular embodiments disclosed and that all

[0045] The serial numbers of components in this paper, such as "first", "second", etc., are only used to distinguish the described objects, and have no order or technical meaning. The "connection" and "coupling" in this paper include direct and indirect connection (coupling) unless otherwise specified.

[0046] In the prior art, the electric heating source of the heat preservation bag adopts an electric heating wire, which can support alternating current power supply and direct current power supply as the power supply. However, the heating power cannot be guaranteed to be the same when the two power supplies are used, so that the power supply of the heat preservation bag is different, and the heat preservation effect is different. In the embodiment of the application, the heating source of the heat preservation bag is a soft rope type electric heating element including a first heating electric heating wire, a second heating electric heating wire and a third heating electric heating wire. Different external voltages are used to heat the corresponding adaptive heating wires, so that even if different external power supplies are connected, the heat preservation effect of the heat preservation bag can be guaranteed to be the same.

[0047] Embodiment one:

[0048] The heat preservation bag disclosed in the embodiment of the application includes a bottom surface, a top surface and four side surfaces, which enclose a closed space for heat preservation. The bottom surface, the top surface and the four side surfaces are respectively provided with a heat preservation layer. In an embodiment, the bottom surface, the top surface and / or the four side surfaces are respectively provided with a heating layer, and the soft rope type electric heating element is wound on the heating layer.

[0049] Please refer to Figure 1Fig. 1 is a schematic diagram of a structure of a soft cord type electric heating element according to an embodiment. The soft cord type electric heating element 100 is a three-core heating wire according to an embodiment. The three-core heating wire includes an insulating protective wire sheath 104 and first, second and third heating wires 101, 102 and 103 respectively insulated and wound around each other in the insulating protective wire sheath 104.

[0050] Fig. 2 is a schematic diagram of a structure of a power supply circuit according to an embodiment. Figure 2 Fig. 3 is a schematic diagram of a structure of a power supply circuit according to an embodiment. The power supply circuit 200 includes an alternating current (AC) power supply circuit 201 and a direct current (DC) power supply circuit 202. The soft cord type electric heating element 100 includes the first, second and third heating wires L10, L20 and L30.

[0051] The AC power supply circuit 201 is electrically connected to the first heating wire L10. The AC power supply circuit 201 is configured to convert an AC power source into a first DC power and output the first DC power to the first heating wire L10 when the AC power source is externally connected, so as to provide the first heating wire L10 with the first DC power as a heating power source. The DC power supply circuit 202 is electrically connected to the second and third heating wires L20 and L30 respectively. The DC power supply circuit 202 is configured to output a DC power source to the second or third heating wire L20 or L30 when the DC power source is externally connected, so as to provide the second or third heating wire L20 or L30 with the DC power source as a heating power source. The DC power source externally connected is a first DC power source or a second DC power source. The first DC power source has a lower voltage than the second DC power source. In an embodiment, the first DC power source has a voltage of 12 volts. In an embodiment, the second DC power source has a voltage of 24 volts. When the DC power supply circuit 202 is externally connected to the first DC power source, the DC power supply circuit 202 provides the first DC power source as the heating power source for the second heating wire L20. When the DC power supply circuit 202 is externally connected to the second DC power source, the DC power supply circuit 202 provides the second DC power source as the heating power source for the third heating wire L30. When the first, second and third heating wires L10, L20 and L30 are respectively used as the heating source of the heat preservation bag, the first, second and third heating wires L10, L20 and L30 have the same heat energy output power.

[0052] In one embodiment, the external AC power supply is the AC first power supply or the AC second power supply, the supply voltage of the AC first power supply is greater than the supply voltage of the AC second power supply. In one embodiment, the supply voltage of the AC first power supply is 230 volts. In one embodiment, the supply voltage of the AC second power supply is 120 volts. When the AC power supply circuit 201 is externally connected to the AC first power supply or the AC second power supply, the AC first power supply or the AC second power supply is converted into the first DC power and output to the first heating wire L10, and the first DC power is used as the heating power of the first heating wire.

[0053] Please refer to Figure 3 In one embodiment, the circuit connection diagram of the power supply circuit is shown in the figure. In one embodiment, the AC power supply circuit 201 includes an AC connection circuit 10, a first reference voltage acquisition circuit 11, a first comparison circuit 12, a first control circuit 13 and a first switching circuit 14. The AC connection circuit 10 includes an AC positive connection end, an AC negative connection end and an AC output end. The AC positive connection end of the AC connection circuit 10 is used to connect with the positive output end of the external AC power supply, the AC negative connection end of the AC connection circuit 10 is used to connect with the negative output end of the external AC power supply, and the AC output end of the AC connection circuit 10 is connected with the first reference voltage acquisition circuit 11, the first switching circuit 14 and the first comparison circuit 12, and is used to output the power of the external AC power supply to the first reference voltage acquisition circuit 11, the first switching circuit 14 and the first comparison circuit 12.

[0054] The first reference voltage acquisition circuit 11 includes a first AC input end and a reference voltage output end. The first AC input end of the first reference voltage acquisition circuit 11 is connected with the AC output end of the AC connection circuit 10, and the reference voltage output end of the first reference voltage acquisition circuit 11 is connected with the first comparison circuit 12 and the first switching circuit 14. The first reference voltage acquisition circuit 11 is used to convert the power of the AC power supply into a DC power and a first reference voltage source VC1 with a preset voltage value, and output the first reference voltage source VC1 to the first comparison circuit 12 and the first switching circuit 14 through the reference voltage output end of the first reference voltage acquisition circuit 11.

[0055] The first comparison circuit 12 comprises an AC power input end, a reference power input end and a comparison result output end. The AC power input end of the first comparison circuit 12 is connected with the AC output end of the AC connection circuit 10, the reference power input end of the first comparison circuit 12 is connected with the reference voltage output end of the first reference voltage acquisition circuit 11, the comparison result output end of the first comparison circuit 12 is connected with the first control circuit 13, the first comparison circuit 12 is used to convert the power of the AC power supply into a first sampling voltage source of DC, compare the voltage of the first sampling voltage source and the first reference voltage source VC1, and output a first result electric signal to the first control circuit 13 according to the comparison result. When the AC power supply circuit 201 is externally connected with the AC first power supply, the first result electric signal is a high level signal, and when the AC power supply circuit 201 is externally connected with the AC second power supply, the first result electric signal is a low level signal.

[0056] The first control circuit 13 comprises a comparison signal input end and a control signal output end, the comparison signal input end of the first control circuit 13 is connected with the comparison result output end of the first comparison circuit 12, the control signal output end of the first control circuit 13 is connected with the first switching circuit 14, the first control circuit 13 is used to output a ground pull-down signal to the first switching circuit 14 according to the first result electric signal, and when the first result electric signal is a high level signal, the control signal output end is grounded, and when the first result electric signal is a low level signal, the control signal output end is made empty.

[0057] The first switching circuit 14 comprises a control signal input end, a reference voltage connection end, an AC power input end and a thermal energy power output end. The control signal input end of the first switching circuit 14 is connected with the control signal output end of the first control circuit 13, the reference voltage connection end of the first switching circuit 14 is connected with the reference voltage output end of the first reference voltage acquisition circuit 11, the AC power input end of the first switching circuit 14 is connected with the AC output end of the AC connection circuit 10, and the thermal energy power output end of the first switching circuit 14 is electrically connected with the first heating wire L10. The first switching circuit 14 is used to convert the AC first power supply input by the AC power input end into a first DC power when the control signal input end is grounded, and output the converted first DC power to the first heating wire L10 through the thermal energy power output end. The first switching circuit 14 is also used to convert the AC second power supply input by the AC power input end into a first DC power when the control signal input end is made empty, and output the converted first DC power to the first heating wire L10 through the thermal energy power output end.

[0058] In an embodiment, the AC connection circuit 10 further comprises a fuse F1, a first indicator lamp Led1 and a first current-limiting resistor R1. One end of the fuse F1 is connected to the AC positive connection end of the AC connection circuit 10, the other end of the fuse F1 is connected to the AC output end of the AC connection circuit 10, the first indicator lamp Led1 and the first current-limiting resistor R1 are connected in series, one end of the series is connected to the AC negative connection end of the AC connection circuit 10, the other end of the series is connected to the AC output end of the AC connection circuit 10.

[0059] In an embodiment, the first reference voltage acquisition circuit 11 further comprises a first capacitor C11, a second capacitor C12, a third capacitor C13, a first diode D11, a second diode D12 and a first resistor R11. One end of the first capacitor C11 is connected to the reference voltage output end of the first reference voltage acquisition circuit 11, the other end is grounded. One end of the second capacitor C12 is connected to the reference voltage output end of the first reference voltage acquisition circuit 11, the other end is grounded. The positive electrode of the first diode D11 is connected to the negative electrode of the second diode D12, the negative electrode of the first diode D11 is connected to the reference voltage output end of the first reference voltage acquisition circuit 11, and the positive electrode of the second diode D12 is grounded. The third capacitor C13 and the first resistor R11 are connected in series, one end of the series is connected to the negative electrode of the second diode D12, the other end of the series is connected to the first AC input end of the first reference voltage acquisition circuit 11.

[0060] In an embodiment, the first comparison circuit 12 further comprises a third diode D21, a second resistor R21, a third resistor R22, a fourth resistor R23, a fifth resistor R24, a sixth resistor R25 and a first comparator T1. The third diode D21, the second resistor R21 and the third resistor R22 are connected in series in turn, one end of the series is connected to the AC power input end of the first comparison circuit 12, the other end of the series is connected to the positive input end of the first comparator T1. One end of the fourth resistor R23 is grounded, the other end is connected to the positive input end of the first comparator T1. One end of the fifth resistor R24 is connected to the reference power supply input end of the first comparison circuit 12, the other end is connected to the negative input end of the first comparator T1. One end of the sixth resistor R25 is grounded, the other end is connected to the negative input end of the first comparator T1. The output end of the first comparator T1 is connected to the comparison result output end of the first comparison circuit 12.

[0061] In an embodiment, the first control circuit 13 further comprises a seventh resistor R31, an eighth resistor R32 and a transistor Q1. One end of the seventh resistor R31 is connected to the ground, and the other end is connected to the comparison signal input end of the first control circuit 13. One end of the eighth resistor R32 is connected to the comparison signal input end of the first control circuit 13, and the other end is connected to the base of the transistor Q1. The emitter of the transistor Q1 is connected to the ground, and the collector of the transistor Q1 is connected to the control signal output end of the first control circuit 13.

[0062] In an embodiment, the first switching circuit 14 further comprises a ninth resistor R41, a fourth diode D41, a fifth diode D42 and a first electronic switch U1. One end of the ninth resistor R41 is connected to the reference voltage connection end of the first switching circuit 14, and the other end is connected to the first electronic switch U1. The fifth diode D42 is connected to the first electronic switch U1. The positive connection end of the fourth diode D41 is connected to the first electronic switch U1 and the alternating current energy input end of the first switching circuit 14, and the negative connection end of the fourth diode D41 is connected to the thermal energy power output end of the first switching circuit 14 and the first electronic switch U1. The first electronic switch U1 is used to output the alternating first power input by the alternating current energy input end to the first heating wire L10 through the fourth diode D41 when the control signal input end is connected to the ground. The first switching circuit 14 is further used to output the alternating second power input by the alternating current energy input end to the first heating wire L10 through the first electronic switch U1 when the control signal input end is empty.

[0063] In an embodiment, the direct current power supply circuit 202 comprises a direct current connection circuit 15, a second reference voltage acquisition circuit 16, a sampling circuit 17, a second comparison circuit 18 and a third comparison circuit 19. The direct current connection circuit 15 comprises a direct current positive connection end, a direct current negative connection end and a direct current output end. The direct current positive connection end of the direct current connection circuit 15 is used to be connected with the positive output end of an externally connected direct current power supply, the direct current negative connection end of the direct current connection circuit 15 is used to be connected with the negative output end of the externally connected direct current power supply, and the direct current output end of the direct current connection circuit 15 is connected with the second reference voltage acquisition circuit 16, the sampling circuit 17, the second comparison circuit 18 and the third comparison circuit 19, and is used to output the direct current power supply. The second reference voltage acquisition circuit 16 comprises a power input end and a reference power output end, the power input end of the second reference voltage acquisition circuit 16 is connected with the direct current output end of the direct current connection circuit 15, and the reference power output end of the second reference voltage acquisition circuit 16 is connected with the sampling circuit 17, the second comparison circuit 18 and the third comparison circuit 19. The second reference voltage acquisition circuit 16 is used to convert the direct current power supply into a second reference voltage source VC2 with a preset voltage value, and output the second reference voltage source VC2 through the reference power output end. The sampling circuit 17 comprises an input first connection end, an input second connection end, an output first connection end, an output second connection end, an output third connection end and an output fourth connection end. The input first connection end of the sampling circuit 17 is connected with the direct current output end of the direct current connection circuit 15, the input second connection end of the sampling circuit 17 is connected with the reference power output end of the second reference voltage acquisition circuit 16, the output first connection end and the output second connection end of the sampling circuit 17 are connected with the second comparison circuit 18, and the output third connection end and the output fourth connection end of the sampling circuit 17 are connected with the third comparison circuit 19. The sampling circuit 17 is used to sample the second reference voltage source and the direct current power supply respectively, and output the results of the two voltage sampling to the second comparison circuit 18 through the output first connection end and the output second connection end, and output to the third comparison circuit 19 through the output third connection end and the output fourth connection end.

[0064] In one embodiment, the second comparison circuit 18 and the third comparison circuit 19 have the same circuit structure, each including a first comparison input, a second comparison input, and a DC power supply output. The first comparison input and the second comparison input of the second comparison circuit 18 are respectively connected to the first output connection terminal and the second output connection terminal of the sampling circuit 17, while the first comparison input and the second comparison input of the third comparison circuit 19 are respectively connected to the third output connection terminal and the fourth output connection terminal of the sampling circuit 17. The DC power supply output of the second comparison circuit 18 is connected to the second heating wire L20, while the DC power supply output of the third comparison circuit 19 is connected to the third heating wire L30. When the DC power supply is the first DC power supply DC1, the second comparison circuit 18 is configured to output the first DC power supply DC1 to the second heating wire L20, thereby using the first DC power supply DC1 as the heating power supply for the second heating wire L20. The third comparison circuit 19 is configured to output the second DC power supply DC2 to the third heating wire L30 when the DC power supply is the second DC power supply DC2, so as to use the second DC power supply DC2 as the heating power supply for the third heating wire L30.

[0065] like Figure 3 As shown, the second reference voltage acquisition circuit 16 further includes a DC conversion circuit Y1, a fourth capacitor C61, a fifth capacitor C62, a sixth capacitor C63, and a sixth diode D61. The anode of the sixth diode D61 is connected to the power input terminal of the second reference voltage acquisition circuit 16, the cathode of the sixth diode D61 is connected to the input terminal of the DC conversion circuit Y1, and the output terminal of the DC conversion circuit Y1 is connected to the reference power output terminal of the second reference voltage acquisition circuit 16. One end of the fourth capacitor C61 is connected to the reference power output terminal of the second reference voltage acquisition circuit 16, and the other end is grounded. One end of the fifth capacitor C62 is connected to the reference power output terminal of the second reference voltage acquisition circuit 16, and the other end is grounded. One end of the sixth capacitor C63 is connected to the input terminal of the DC conversion circuit Y1, and the other end is grounded.

[0066] In one embodiment, the sampling circuit 17 further includes a tenth resistor R71, an eleventh resistor R72, a twelfth resistor R73, a thirteenth resistor R74, and a seventh diode D71. The seventh diode D71 and the tenth resistor R71 are connected in series, with one end of the series connection connected to the first input connection terminal of the sampling circuit 17 and the other end of the series connection connected to the second output connection terminal and the third output connection terminal of the sampling circuit 17. One end of the eleventh resistor R72 is connected to the second input connection terminal of the sampling circuit 17, and the other end is grounded. One end of the twelfth resistor R73 is connected to the second input connection terminal of the sampling circuit 17, and the other end is connected to the first output connection terminal and the fourth output connection terminal of the sampling circuit 17. One end of the thirteenth resistor R74 is connected to the first output connection terminal of the sampling circuit 17, and the other end is grounded.

[0067] In one embodiment, the second reference voltage acquisition circuit 16 also includes a second indicator light Led2 and a second current limiting resistor R2. The second indicator light Led2 and the second current limiting resistor R2 are connected in series, one end of the series connection is connected to the reference power supply output end of the second reference voltage acquisition circuit 16, and the other end is grounded.

[0068] In one embodiment, the second comparison circuit 18 further includes a second comparator T2, a fourteenth resistor R81, a fifteenth resistor R82, a sixteenth resistor R83, an eighth diode D81, a second electronic switch U2, and a second transistor Q2. One end of the fourteenth resistor R81 is connected to the output of the second comparator T2, and the other end is connected to the base of the second transistor Q2. One end of the fifteenth resistor R82 is connected to the base of the second transistor Q2, and the other end is grounded. The emitter of the second transistor Q2 is grounded, and the collector of the second transistor Q2 is connected to the second electronic switch U2. Both ends of the eighth diode D81 are connected to the second electronic switch U2. One end of the sixteenth resistor R83 is connected to the second electronic switch U2, and the other end is connected to the reference power supply output of the second reference voltage acquisition circuit 16. The second electronic switch U2 is also connected to the DC output of the DC connection circuit 15.

[0069] In one embodiment, the third comparison circuit further includes a third comparator T3, a seventeenth resistor 91, an eighteenth resistor R92, a nineteenth resistor R93, a ninth diode D91, a third electronic switch U3, and a third transistor Q3. One end of the seventeenth resistor R91 is connected to the output of the third comparator T3, and the other end is connected to the base of the third transistor Q3. One end of the eighteenth resistor R92 is connected to the base of the third transistor Q3, and the other end is grounded. The emitter of the third transistor Q3 is grounded, and the collector of the third transistor Q3 is connected to the third electronic switch U3. Both ends of the ninth diode D91 are connected to the third electronic switch U3. One end of the nineteenth resistor R93 is connected to the third electronic switch U3, and the other end is connected to the reference power supply output of the second reference voltage acquisition circuit 16. The third electronic switch U3 is also connected to the DC output of the DC connection circuit 15.

[0070] like Figure 2 As shown, in one embodiment, the thermal insulation bag further includes an interface adapter 300 for electrically connecting the AC power supply circuit 201 to an external AC power source, and for electrically connecting the DC power supply circuit 202 to an external DC power source. The interface adapter 300 can only be connected to one external AC power source or one external DC power source at a time.

[0071] Please refer to Figure 4For another embodiment of the circuit connection diagram of the power supply circuit, the AC power supply circuit 201 only supports an external AC power supply, i.e. the external AC power supply is the AC first power supply. In an embodiment of the present application, the first heating wire L10, the second heating wire L20 and the third heating wire L30 work at different DC voltages respectively. When the interface adapter is connected to the AC power supply, the first indicator lamp Led1 is lit after power-on, and the first DC voltage obtained by converting the AC first power supply is used to heat the first heating wire L10, and the temperature is controlled by the temperature control. When the interface adapter is connected to the DC power supply (DC first power supply 12V or DC second power supply 24V), the second reference voltage source of 9V is output after being stabilized by the DC conversion circuit Y1, and the second indicator lamp Led2 is lit at this time. The sampling circuit divides the second reference voltage source of 9V by resistance to obtain a comparison reference voltage of 3V, and outputs the comparison reference voltage to the positive input terminal of the second comparator T2 of the second comparison circuit and the negative input terminal of the third comparator T3 of the third comparison circuit respectively. The sampling circuit further divides the external DC power supply (12V or 24V) to obtain a comparison reference voltage of 2.3V when the external power supply is the DC first power supply of 12V, and a comparison reference voltage of 4.6V when the external power supply is the DC second power supply of 24V. The comparison reference voltage is output to the negative input terminal of the second comparator T2 of the second comparison circuit and the positive input terminal of the third comparator T3 of the third comparison circuit respectively. When the DC power supply is the DC first power supply, the second triode Q2 of the second comparison circuit is turned on, and the second electronic switch U2 of the second comparison circuit outputs the DC power supply DC1 of 12V to the second heating wire L20, so that the DC first power supply is heated by the second heating wire L20, and the temperature is controlled by the temperature control. When the DC power supply is the DC second power supply of 24V, the third triode Q3 of the third comparison circuit is turned on, and the third electronic switch U3 of the third comparison circuit outputs the DC power supply DC2 of 24V to the third heating wire L30, so that the DC second power supply is heated by the third heating wire L30, and the temperature is controlled by the temperature control. The first heating wire L10, the second heating wire L20 and the third heating wire L30 do not interfere with each other, and three voltage sources (AC power supply, DC first power supply and DC second power supply) are heated by one three-core heating wire. In an embodiment, the second electronic switch U2 and the third electronic switch U3 are relay switches.

[0072] As Figure 3As shown, in an embodiment of the present application, when the AC power connected by the interface adapter is 120V, the first reference voltage source obtained by the first reference voltage obtaining circuit is 11.3V, then the negative input end of the first comparator T1 obtains a comparison voltage of about 3.4V, and the positive input end of the first comparator T1 obtains a comparison voltage of 2.15V (divided by resistors R21, R22 and R23). At this time, the output end of the first comparator T1 outputs a low level, and the first transistor Q1 closes the first electronic switch U1 (in an embodiment, the first electronic switch U1 is a relay SW DPDT, and the relay is in a normally closed state when not attracted). The first electronic switch U1 makes the 120V AC power not pass through the fourth diode D41, and directly output to the first heating wire L10 to realize heating. When the AC power connected by the interface adapter is 230V, the positive input end of the first comparator T1 obtains a comparison voltage of 4.13V, at this time, the output end of the first comparator T1 outputs a high level, the first transistor Q1 is turned on, and the first electronic switch U1 (the relay SW DPDT) is opened, and the 230V AC power passes through the fourth diode D41 to form a power supply circuit for the first heating wire L10 to realize heating through the first heating wire L10. In the power supply circuit as shown, Figure 3 In the power supply circuit as shown, four external power sources (120V or 230V AC power, 12V or 24V DC power) realize heating through one three-core heating wire, do not interfere with each other, and through setting the resistance values of the first heating wire L10, the second heating wire L20 and the third heating wire L30, the heating powers of the four different external power sources are guaranteed to be consistent.

[0073] The power supply circuit disclosed in the embodiments of the present application is used to provide power for the heating source of the heat preservation bag when an external AC power source or a DC power source is connected, and includes an AC power supply circuit and a DC power supply circuit. The heating source of the heat preservation bag includes soft cable type electric heating elements of the first heating wire, the second heating wire and the third heating wire. The AC power supply circuit is used to convert the external AC power source into first DC power and then output the first DC power to the first heating wire, and the DC power supply circuit is used to output the external first DC power source or the second DC power source to the second heating wire and the third heating wire connected thereto. Since the first, second and third heating wires each have the same heat energy output power, the heat preservation bag can support different external power sources and also can guarantee the same heat preservation effect under the condition of connecting different power sources.

[0074] The above application of specific examples is used to illustrate the present application, which is only used to help understand the present application, and does not limit the present application. According to the idea of the present application, those skilled in the art can make several simple deductions, deformations or substitutions.

Claims

1. A power supply circuit for a thermal bag for providing power to a heating source of the thermal bag when an external AC or DC power source is connected, characterized in that, The AC power supply circuit and the DC power supply circuit are included; The heating source of the heat preservation bag is a soft rope type electric heating element, which includes a first heating electric heating wire, a second heating electric heating wire and a third heating electric heating wire; The AC power supply circuit is electrically connected with the first heating electric heating wire; when the AC power supply circuit is externally connected with the AC power supply, the AC power supply is converted into first DC power and then output to the first heating electric heating wire, so that the first DC power is used as the heating power source of the first heating electric heating wire; The DC power supply circuit is electrically connected with the second heating electric heating wire and the third heating electric heating wire respectively; when the DC power supply circuit is externally connected with the DC power supply, the DC power supply is output to the second heating electric heating wire or the third heating electric heating wire, so that the second heating electric heating wire or the third heating electric heating wire is provided with the heating power source; wherein the externally connected DC power supply is a DC first power supply or a DC second power supply, the power supply voltage of the DC first power supply is smaller than that of the DC second power supply; when the DC power supply circuit is externally connected with the DC first power supply, the DC power supply circuit uses the DC first power supply as the heating power source of the second heating electric heating wire; when the DC power supply circuit is externally connected with the DC second power supply, the DC power supply circuit uses the DC second power supply as the heating power source of the third heating electric heating wire; When the first heating electric heating wire, the second heating electric heating wire and the third heating electric heating wire are used as the heating source of the heat preservation bag respectively, the heat energy output power of each of them is the same.

2. The power supply circuit of claim 1, wherein, The externally connected AC power supply is an AC first power supply or an AC second power supply, the power supply voltage of the AC first power supply is greater than that of the AC second power supply; When the AC power supply circuit is externally connected with the AC first power supply or the AC second power supply, the AC first power supply or the AC second power supply is converted into the first DC power and then output to the first heating electric heating wire, and the first DC power is used as the heating power source of the first heating electric heating wire.

3. The power supply circuit of claim 2, wherein, The AC power supply circuit includes an AC connection circuit, a first reference voltage acquisition circuit, a first comparison circuit, a first control circuit and a first switching circuit; The AC connection circuit includes an AC positive connection end, an AC negative connection end and an AC output end; the AC positive connection end of the AC connection circuit is used to be connected with the positive output end of the externally connected AC power supply, and the AC negative connection end of the AC connection circuit is used to be connected with the negative output end of the externally connected AC power supply; the AC output end of the AC connection circuit is connected with the first reference voltage acquisition circuit, the first switching circuit and the first comparison circuit, and is used to output the electric energy of the externally connected AC power supply to the first reference voltage acquisition circuit, the first switching circuit and the first comparison circuit; The first reference voltage acquisition circuit comprises a first AC input end and a reference voltage output end, the first AC input end of the first reference voltage acquisition circuit is connected with the AC output end of the AC connection circuit, and the reference voltage output end of the first reference voltage acquisition circuit is connected with the first comparison circuit and the first switching circuit; the first reference voltage acquisition circuit is used for converting the electric energy of the AC power supply into a first reference voltage source with a preset voltage value and a direct current, and outputting the first reference voltage source to the first comparison circuit and the first switching circuit through the reference voltage output end of the first reference voltage acquisition circuit; The first comparison circuit comprises an AC electric energy input end, a reference power supply input end and a comparison result output end; the AC electric energy input end of the first comparison circuit is connected with the AC output end of the AC connection circuit, the reference power supply input end of the first comparison circuit is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the comparison result output end of the first comparison circuit is connected with the first control circuit; the first comparison circuit is used for converting the electric energy of the AC power supply into a first sampling voltage source with a direct current, comparing the voltage of the first sampling voltage source with the voltage of the first reference voltage source, and outputting a first result electric signal to the first control circuit according to the comparison result; when the AC power supply circuit is externally connected with the AC first power supply, the first result electric signal is a high-level signal, and when the AC power supply circuit is externally connected with the AC second power supply, the first result electric signal is a low-level signal; The first control circuit comprises a comparison signal input end and a control signal output end; the comparison signal input end of the first control circuit is connected with the comparison result output end of the first comparison circuit, and the control signal output end of the first control circuit is connected with the first switching circuit; the first control circuit is used for outputting a pull-down signal grounded to the first switching circuit according to the first result electric signal, and grounding the control signal output end when the first result electric signal is a high-level signal, and making the control signal output end empty when the first result electric signal is a low-level signal. The first switching circuit comprises a control signal input end, a reference voltage connection end, an alternating current energy input end and a thermal energy power output end; the control signal input end of the first switching circuit is connected with the control signal output end of the first control circuit, the reference voltage connection end of the first switching circuit is connected with the reference voltage output end of the first reference voltage acquisition circuit, the alternating current energy input end of the first switching circuit is connected with the alternating current output end of the alternating current connection circuit, and the thermal energy power output end of the first switching circuit is connected with the first heating electric heating wire; the first switching circuit is used for converting the alternating current first power input by the alternating current energy input end into the first direct current when the control signal input end is grounded, and outputting the converted first direct current to the first heating electric heating wire through the thermal energy power output end; the first switching circuit is also used for converting the alternating current second power input by the alternating current energy input end into the first direct current when the control signal input end is empty, and outputting the converted first direct current to the first heating electric heating wire through the thermal energy power output end.

4. The power supply circuit of claim 3, wherein, The alternating current connection circuit further comprises a fuse F1, a first indicator lamp Led1 and a first current limiting resistor R1; one end of the fuse F1 is connected with the alternating current positive connection end of the alternating current connection circuit, and the other end of the fuse F1 is connected with the alternating current output end of the alternating current connection circuit; the first indicator lamp Led1 and the first current limiting resistor R1 are connected in series, one end after the series connection is connected with the alternating current negative connection end of the alternating current connection circuit, and the other end after the series connection is connected with the alternating current output end of the alternating current connection circuit; And / or, the first reference voltage acquisition circuit further comprises a first capacitor C11, a second capacitor C12, a third capacitor C13, a first diode D11, a second diode D12 and a first resistor R11; one end of the first capacitor C11 is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the other end is grounded; one end of the second capacitor C12 is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the other end is grounded; the positive electrode of the first diode D11 is connected with the negative electrode of the second diode D12, the negative electrode of the first diode D11 is connected with the reference voltage output end of the first reference voltage acquisition circuit, and the positive electrode of the second diode D12 is grounded; the third capacitor C13 and the first resistor R11 are connected in series, one end after the series connection is connected with the negative electrode of the second diode D12, and the other end after the series connection is connected with the first alternating current input end of the first reference voltage acquisition circuit; And / or, the first comparison circuit further comprises a third diode D21, a second resistor R21, a third resistor R22, a fourth resistor R23, a fifth resistor R24, a sixth resistor R25 and a first comparator T1; the third diode D21, the second resistor R21 and the third resistor R22 are connected in series, one end of the series connection is connected with the AC power input end of the first comparison circuit, the other end of the series connection is connected with the positive input end of the first comparator T1; one end of the fourth resistor R23 is grounded, the other end is connected with the positive input end of the first comparator T1; one end of the fifth resistor R24 is connected with the reference power input end of the first comparison circuit, the other end is connected with the negative input end of the first comparator T1; one end of the sixth resistor R25 is grounded, the other end is connected with the negative input end of the first comparator T1; the output end of the first comparator T1 is connected with the comparison result output end of the first comparison circuit; And / or, the first control circuit further comprises a seventh resistor R31, an eighth resistor R32 and a triode Q1; one end of the seventh resistor R31 is grounded, the other end is connected with the comparison signal input end of the first control circuit; one end of the eighth resistor R32 is connected with the comparison signal input end of the first control circuit, the other end is connected with the base of the triode Q1; the emitter of the triode Q1 is grounded, the collector of the triode Q1 is connected with the control signal output end of the first control circuit; And / or, the first switching circuit further comprises a ninth resistor R41, a fourth diode D41, a fifth diode D42 and a first electronic switch U1; one end of the ninth resistor R41 is connected with the reference voltage connection end of the first switching circuit, the other end is connected with the first electronic switch U1; the fifth diode D42 is connected with the first electronic switch U1 at both ends; the positive connection end of the fourth diode D41 is connected with the first electronic switch U1 and the AC power input end of the first switching circuit, the negative connection end of the fourth diode D41 is connected with the first electronic switch U1 and the thermal energy power output end of the first switching circuit; the first electronic switch U1 is used for outputting the AC first power input by the AC power input end to the first heating wire through the fourth diode D41 when the control signal input end is grounded; the first switching circuit is further used for outputting the AC second power input by the AC power input end to the first heating wire through the first electronic switch U1 when the control signal input end is empty.

5. The power supply circuit of claim 1, wherein, The direct current power supply circuit comprises a direct current connection circuit, a second reference voltage acquisition circuit, a sampling circuit, a second comparison circuit and a third comparison circuit; The direct current connection circuit comprises a direct current positive connection end, a direct current negative connection end and a direct current output end; the direct current positive connection end of the direct current connection circuit is used for being connected with a positive output end of the external direct current power supply, the direct current negative connection end of the direct current connection circuit is used for being connected with a negative output end of the external direct current power supply, and the direct current output end of the direct current connection circuit is connected with the second reference voltage acquisition circuit, the sampling circuit, the second comparison circuit and the third comparison circuit and is used for outputting the direct current power supply; The second reference voltage acquisition circuit comprises a power input end and a reference power output end, the power input end of the second reference voltage acquisition circuit is connected with the direct current output end of the direct current connection circuit, the reference power output end of the second reference voltage acquisition circuit is connected with the sampling circuit, the second comparison circuit and the third comparison circuit; the second reference voltage acquisition circuit is used for converting the direct current power supply into a second reference voltage source with a preset voltage value and outputting the second reference voltage source through the reference power output end; The sampling circuit comprises an input first connection end, an input second connection end, an output first connection end, an output second connection end, an output third connection end and an output fourth connection end; the input first connection end of the sampling circuit is connected with the direct current output end of the direct current connection circuit, the input second connection end of the sampling circuit is connected with the reference power output end of the second reference voltage acquisition circuit, the output first connection end and the output second connection end of the sampling circuit are connected with the second comparison circuit, and the output third connection end and the output fourth connection end of the sampling circuit are connected with the third comparison circuit; the sampling circuit is used for respectively performing voltage division sampling on the second reference voltage source and the direct current power supply, outputting two voltage division sampling results to the second comparison circuit through the output first connection end and the output second connection end and then outputting the two voltage division sampling results to the third comparison circuit through the output third connection end and the output fourth connection end; The circuit structure of the second comparison circuit and the third comparison circuit is same, and each includes a first comparison input end, a second comparison input end and a direct current power output end; the first comparison input end and the second comparison input end of the second comparison circuit are connected with the output first connection end and the output second connection end of the sampling circuit respectively, the first comparison input end and the second comparison input end of the third comparison circuit are connected with the output third connection end and the output fourth connection end of the sampling circuit respectively, the direct current power output end of the second comparison circuit is connected with the second heating electric heating wire, and the direct current power output end of the third comparison circuit is connected with the third heating electric heating wire; the second comparison circuit is used for outputting the direct current first power to the second heating electric heating wire when the direct current power is the direct current first power, so as to take the direct current first power as the heating power of the second heating electric heating wire; and the third comparison circuit is used for outputting the direct current second power to the third heating electric heating wire when the direct current power is the direct current second power, so as to take the direct current second power as the heating power of the third heating electric heating wire.

6. The power supply circuit of claim 5, wherein, The second reference voltage acquisition circuit further includes a DC conversion circuit Y1, a fourth capacitor C61, a fifth capacitor C62, a sixth capacitor C63 and a sixth diode D61; a positive electrode of the sixth diode D61 is connected with a power input end of the second reference voltage acquisition circuit, and a negative electrode of the sixth diode D61 is connected with an input end of the DC conversion circuit Y1; an output end of the DC conversion circuit Y1 is connected with a reference power output end of the second reference voltage acquisition circuit; one end of the fourth capacitor C61 is connected with the reference power output end of the second reference voltage acquisition circuit, and the other end is grounded; one end of the fifth capacitor C62 is connected with the reference power output end of the second reference voltage acquisition circuit, and the other end is grounded; one end of the sixth capacitor C63 is connected with the input end of the DC conversion circuit Y1, and the other end is grounded; and / or, the sampling circuit further includes a tenth resistor R71, an eleventh resistor R72, a twelfth resistor R73, a thirteenth resistor R74 and a seventh diode D71; the seventh diode D71 and the tenth resistor R71 are connected in series, one end after series connection is connected with an input first connection end of the sampling circuit, and the other end after series connection is connected with an output second connection end and an output third connection end of the sampling circuit; one end of the eleventh resistor R72 is connected with an input second connection end of the sampling circuit, and the other end is grounded; one end of the twelfth resistor R73 is connected with the input second connection end of the sampling circuit, and the other end is connected with an output first connection end and an output fourth connection end of the sampling circuit; one end of the thirteenth resistor R74 is connected with the output first connection end of the sampling circuit, and the other end is grounded.

7. The power supply circuit of claim 6, wherein, The second reference voltage acquisition circuit further comprises a second indicator lamp Led2 and a second current limiting resistor R2, which are connected in series, one end of which is connected with the reference power output end of the second reference voltage acquisition circuit, and the other end is grounded.

8. The power supply circuit of claim 6, wherein, The second comparison circuit further comprises a second comparator T2, a fourteenth resistor R81, a fifteenth resistor R82, a sixteenth resistor R83, an eighth diode D81, a second electronic switch U2 and a second transistor Q2; One end of the fourteenth resistor R81 is connected with the output end of the second comparator T2, and the other end is connected with the base of the second transistor Q2; one end of the fifteenth resistor R82 is connected with the base of the second transistor Q2, and the other end is grounded; the emitter of the second transistor Q2 is grounded, and the collector of the second transistor Q2 is connected with the second electronic switch U2; the two ends of the eighth diode D81 are connected with the second electronic switch U2; one end of the sixteenth resistor R83 is connected with the second electronic switch U2, and the other end is connected with the reference power output end of the second reference voltage acquisition circuit; the second electronic switch U2 is further connected with the direct current output end of the direct current connection circuit; And / or, the third comparison circuit further comprises a third comparator T3, a seventeenth resistor R91, an eighteenth resistor R92, a nineteenth resistor R93, a ninth diode D91, a third electronic switch U3 and a third transistor Q3; One end of the seventeenth resistor R91 is connected with the output end of the third comparator T3, and the other end is connected with the base of the third transistor Q3; one end of the eighteenth resistor R92 is connected with the base of the third transistor Q3, and the other end is grounded; the emitter of the third transistor Q3 is grounded, and the collector of the third transistor Q3 is connected with the third electronic switch U3; the two ends of the ninth diode D91 are connected with the third electronic switch U3; one end of the nineteenth resistor R93 is connected with the third electronic switch U3, and the other end is connected with the reference power output end of the second reference voltage acquisition circuit; the third electronic switch U3 is further connected with the direct current output end of the direct current connection circuit.

9. An insulating bag, characterized in that The power supply circuit comprises the power supply circuit according to any one of claims 1 to 8. The power supply circuit comprises the power supply circuit according to any one of claims 1 to 8.

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