Soft cable type electric heating element for heat preservation bag and heat preservation bag

Abstract

The utility model discloses a soft cable type electric heating element for a heat preservation bag and the heat preservation bag, and the soft cable type electric heating element is a three-core heating wire and comprises an insulation protection wire sheath, and a first heating electric heating wire, a second heating electric heating wire and a third heating electric heating wire which are arranged in the insulation protection wire sheath, are insulated from each other and are wound with each other. When the power supply of the heat preservation bag is an alternating-current power supply, the first heating electric heating wire serves as a heating source, and when the power supply of the heat preservation bag is a direct-current first power supply or a direct-current second power supply with different voltage values, the second heating electric heating wire or the third heating electric heating wire serves as a heating source. Due to the fact that the heat energy output power of the first electric heating wire, the second electric heating wire and the third electric heating wire is the same, the heat preservation bag supports power supply of different external power sources and can keep the same heat preservation effect under the condition that the different external power sources are connected.

Description

Technical Field

[0001] The present invention relates to the technical field of electric heating, and particularly relates to a flexible cord type electric heating element for a thermal insulation bag and a thermal insulation bag. Background Art

[0002] In real life, people always need to use thermal insulation bags to keep warm food warm. However, no matter how good the thermal insulation bag is, as time goes by, the heat of the food will still disappear and finally become cold. The only difference in the quality of the thermal insulation bag lies in the length of the heat preservation time, and it cannot always keep the food warm. If the food becomes cold due to being placed for too long, it will seriously affect the taste of the food. And some people are not suitable to eat cold food due to gastrointestinal problems and can only choose to discard it, resulting in food waste. If you choose to reheat the food, you need to find an external heating device (such as a microwave oven). Once you can't find it, you can't reheat the food, and the heating conditions are greatly restricted. To solve the above problems, an electric heating type thermal insulation bag has emerged on the market. A heating layer is provided in the bottom, top, and / or surrounding compartments of the thermal insulation bag to convert the electrical energy of an external power supply into heat energy through the heating layer to provide a heat source for the thermal insulation bag. However, all such products only support one type of external power supply (mains electricity or a DC power adapter). The original intention of using a thermal insulation bag is to be portable, and the single type of external power supply greatly restricts 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 that supports multiple types of external power supplies. Summary of the Invention

[0003] The main technical problem to be solved by the present invention is to make the thermal insulation bag compatible with multiple external power supplies.

[0004] According to a first aspect, in one embodiment, a flexible cord type electric heating element for a thermal insulation bag is provided, which is used as a heat source for the thermal insulation bag. The flexible cord type electric heating element is a three-core heating wire, and the three-core heating wire includes an insulating protective wire sheath and a first heating electric wire, a second heating electric wire, and a third heating electric wire that are respectively insulated and wound around each other inside the insulating protective wire sheath.

[0005] When the power supply of the thermal insulation bag is an AC power supply, the first heating electric wire serves as the heat source for the thermal insulation bag; when the power supply of the thermal insulation bag is a DC power supply, the second heating electric wire or the third heating electric wire serves as the heat source for the thermal insulation bag. Among them, the DC power supply includes a DC first power supply and a DC second power supply, and the supply voltage of the DC first power supply is less than the supply voltage of the DC second power supply. When the power supply of the thermal insulation bag is the DC first power supply, the second heating electric wire serves as the heat source for the thermal insulation bag, and when the power supply of the thermal insulation bag is the DC second power supply, the third heating electric wire serves as the heat source for the thermal insulation bag.

[0006] When the first heating electric wire, the second heating electric wire, and the third heating electric wire are respectively used as the heating sources of the heat preservation bag, their respective heat energy output powers are the same.

[0007] In one embodiment, the first heating electric wire, the second heating electric wire, and the third heating electric wire have the same length.

[0008] According to a second aspect, in one embodiment, a heat preservation bag is provided, including a power supply circuit and a flexible cord type electric heating element as described in the first aspect.

[0009] The power supply circuit is used to provide electric energy for the heating source of the heat preservation bag when externally connecting an AC power supply or a DC power supply; the power supply circuit includes an AC power supply circuit and a DC power supply circuit;

[0010] The AC power supply circuit is electrically connected to the first heating electric wire; when externally connecting the AC power supply, the AC power supply circuit converts the AC power supply into a first direct current and outputs it to the first heating electric wire, so as to use the first direct current as the heating power supply of the first heating electric wire;

[0011] The DC power supply circuit is respectively electrically connected to the second heating electric wire and the third heating electric wire; when externally connecting the DC power supply, the DC power supply circuit outputs the DC power supply to the second heating electric wire or the third heating electric wire to provide a heating power supply for the second heating electric wire or the third heating electric wire; wherein, the externally connected DC power supply is a first DC power supply or a second DC power supply, and the supply voltage of the first DC power supply is less than the supply voltage of the second DC power supply; when the DC power supply circuit externally connects the first DC power supply, the DC power supply circuit uses the first DC power supply as the heating power supply of the second heating electric wire; when the DC power supply circuit externally connects the second DC power supply, the DC power supply circuit uses the second DC power supply as the heating power supply of the third heating electric wire.

[0012] In one embodiment, the heat preservation bag further includes a bottom surface, a top surface, and four side surfaces, and the bottom surface, the top surface, and the four side surfaces enclose to form a closed space for heat preservation, and heat preservation layers are respectively provided on the bottom surface, the top surface, and the four side surfaces.

[0013] In one embodiment, heating layers are respectively further provided on the bottom surface, the top surface, and / or the four side surfaces, and the flexible cord type electric heating element is wound and arranged on the heating layer.

[0014] In one embodiment, the thermal insulation bag further includes an interface adapter for electrically connecting the AC power supply circuit and an external AC power supply, and also for electrically connecting the DC power supply circuit and an external DC power supply; wherein, the interface adapter can only externally connect one AC power supply or one DC power supply at the same time.

[0015] In one embodiment, the external AC power supply is an AC first power supply or an AC second power supply, and the supply voltage of the AC first power supply is greater than the supply voltage of the AC second power supply;

[0016] When the AC power supply circuit externally connects 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 direct current and output to the first heating electric wire, and the first direct current is used as the heating DC power supply of the first heating electric wire.

[0017] In one embodiment, 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;

[0018] 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 connect to the positive output end of the external AC power supply, and the AC negative connection end of the AC connection circuit is used to connect to the negative output end of the external AC power supply; the AC output end of the AC connection circuit is connected to 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 external AC power supply to the first reference voltage acquisition circuit, the first switching circuit, and the first comparison circuit;

[0019] The first reference voltage acquisition circuit includes 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 to the AC output end of the AC connection circuit, and the reference voltage output end of the first reference voltage acquisition circuit is connected to the first comparison circuit and the first switching circuit; the first reference voltage acquisition circuit is used to convert the electric energy of the AC power supply into a DC first reference voltage source with a preset voltage value, and output 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;

[0020] The first comparison circuit includes an AC power input terminal, a reference power input terminal, and a comparison result output terminal; the AC power input terminal of the first comparison circuit is connected to the AC output terminal of the AC connection circuit, the reference power input terminal of the first comparison circuit is connected to the reference voltage output terminal of the first reference voltage acquisition circuit, and the comparison result output terminal of the first comparison circuit is connected to the first control circuit; the first comparison circuit is configured to convert the electrical energy of the AC power supply into a DC first sampling voltage source, compare the voltage magnitudes of the first sampling voltage source and the first reference voltage source, and output a first result electrical signal to the first control circuit according to the comparison result; when the AC power supply circuit is externally connected to the first AC power supply, the first result electrical signal is a high-level signal, and when the AC power supply circuit is externally connected to the second AC power supply, the first result electrical signal is a low-level signal;

[0021] The first control circuit includes a comparison signal input terminal and a control signal output terminal; the comparison signal input terminal of the first control circuit is connected to the comparison result output terminal of the first comparison circuit, and the control signal output terminal of the first control circuit is connected to the first switching circuit; the first control circuit is configured to output a pull-down signal to the ground to the first switching circuit according to the first result electrical signal, and when the first result electrical signal is a high-level signal, ground the control signal output terminal, and when the first result electrical signal is a low-level signal, make the control signal output terminal empty;

[0022] The first switching circuit includes a control signal input terminal, a reference voltage connection terminal, an AC power input terminal, and a thermal energy power output terminal; the control signal input terminal of the first switching circuit is connected to the control signal output terminal of the first control circuit, the reference voltage connection terminal of the first switching circuit is connected to the reference voltage output terminal of the first reference voltage acquisition circuit, the AC power input terminal of the first switching circuit is connected to the AC output terminal of the AC connection circuit, and the thermal energy power output terminal of the first switching circuit is electrically connected to the first heating electric wire; the first switching circuit is configured to convert the first AC power input from the AC power input terminal into the first direct current when the control signal input terminal is grounded, and output the converted first direct current to the first heating electric wire through the thermal energy power output terminal; the first switching circuit is further configured to convert the second AC power input from the AC power input terminal into the first direct current when the control signal input terminal is empty, and output the converted first direct current to the first heating electric wire through the thermal energy power output terminal.

[0023] In one embodiment, the DC power supply circuit includes a DC connection circuit, a second reference voltage acquisition circuit, a sampling circuit, a second comparison circuit, and a third comparison circuit;

[0024] The DC connection circuit includes a DC positive connection terminal, a DC negative connection terminal, and a DC output terminal; the DC positive connection terminal of the DC connection circuit is used to connect to the positive output terminal of the external DC power supply, the DC negative connection terminal of the DC connection circuit is used to connect to the negative output terminal of the external DC power supply, and the DC output terminal of the DC connection circuit is connected to the second reference voltage acquisition circuit, the sampling circuit, the second comparison circuit, and the third comparison circuit, and is used to output the DC power supply;

[0025] The second reference voltage acquisition circuit includes a power input terminal and a reference power output terminal. The power input terminal of the second reference voltage acquisition circuit is connected to the DC output terminal of the DC connection circuit, and the reference power output terminal of the second reference voltage acquisition circuit is connected to the sampling circuit, the second comparison circuit, and the third comparison circuit; the second reference voltage acquisition circuit is used to convert the DC power supply into a second reference voltage source with a preset voltage value and output the second reference voltage source through the reference power output terminal;

[0026] The sampling circuit includes an input first connection terminal, an input second connection terminal, an output first connection terminal, an output second connection terminal, an output third connection terminal, and an output fourth connection terminal; the input first connection terminal of the sampling circuit is connected to the DC output terminal of the DC connection circuit, the input second connection terminal of the sampling circuit is connected to the reference power output terminal of the second reference voltage acquisition circuit, the output first connection terminal and the output second connection terminal of the sampling circuit are connected to the second comparison circuit, and the output third connection terminal and the output fourth connection terminal of the sampling circuit are connected to the third comparison circuit; the sampling circuit is used to perform voltage division sampling on the second reference voltage source and the DC power supply respectively, and output the result electrical signals of the two voltage division samplings to the second comparison circuit through the output first connection terminal and the output second connection terminal, and then output to the third comparison circuit through the output third connection terminal and the output fourth connection terminal;

[0027] The second comparison circuit and the third comparison circuit have the same circuit structure, each including a first comparison input terminal, a second comparison input terminal, and a DC power output terminal; the first comparison input terminal and the second comparison input terminal of the second comparison circuit are respectively connected to the first output terminal and the second output terminal of the sampling circuit, the first comparison input terminal and the second comparison input terminal of the third comparison circuit are respectively connected to the third output terminal and the fourth output terminal of the sampling circuit, the DC power output terminal of the second comparison circuit is connected to the second heating wire, and the DC power output terminal of the third comparison circuit is connected to the third heating wire; the second comparison circuit is configured to output the DC first power supply to the second heating wire when the DC power supply is the DC first power supply, so as to use the DC first power supply as the heating power supply of the second heating wire; the third comparison circuit is configured to output the DC second power supply to the third heating wire when the DC power supply is the DC second power supply, so as to use the DC second power supply as the heating power supply of the third heating wire.

[0028] In one embodiment, the supply voltage of the AC first power supply is 230V; the supply voltage of the AC second power supply is 120V; the supply voltage of the DC first power supply is 12V; the supply voltage of the DC second power supply is 24V.

[0029] According to the heat preservation bag of the above embodiment, since the heat output powers of the first, second, and third heating wires for the heating source are the same, the heat preservation bag can support different external power supplies and maintain the same heat preservation effect under different external power supply conditions. Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of a flexible cord type electric heating element in an embodiment;

[0031] Figure 2 It is a schematic structural connection diagram of a power supply circuit in an embodiment;

[0032] Figure 3 It is a schematic circuit connection diagram of a power supply circuit in an embodiment;

[0033] Figure 4 It is a schematic circuit connection diagram of a power supply circuit in another embodiment. Detailed Embodiments

[0034] The present invention will be further described in detail below with reference to specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are denoted by related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can readily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid obscuring the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and general technical knowledge in the art.

[0035] In addition, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean a necessary sequence, unless it is stated that a certain sequence must be followed.

[0036] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The terms "connection" and "coupling" used in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0037] In the prior art, the heating source of the heat preservation bag all adopts an electric heating wire. Even though it supports both AC power and DC power as the power supply, it cannot ensure that the heating power is the same when the two power supplies are used. That is, when the power supply of the heat preservation bag is different, its heat preservation effect is different. In the embodiment of the present application, the heating source of the heat preservation bag is a flexible cord type electric heating element including a first heating electric wire, a second heating electric wire, and a third heating electric wire. For different external voltages, the corresponding adapted heating electric wire is used for heating, so as to ensure that the heat preservation effect of the heat preservation bag is the same even when different external power supplies are connected.

[0038] Embodiment 1:

[0039] The heat preservation bag disclosed in the embodiment of the present application includes a bottom surface, a top surface, and four side surfaces. The bottom surface, the top surface, and the four side surfaces enclose a closed space for heat preservation. Among them, heat preservation layers are respectively provided on the bottom surface, the top surface, and the four side surfaces. In one embodiment, heating layers are also respectively provided on the bottom surface, the top surface, and / or the four side surfaces, and a flexible cord type electric heating element is wound around the heating layers.

[0040] Please refer to Figure 1, which is a schematic structural diagram of a flexible cable type electric heating element in an embodiment. In one embodiment, the flexible cable type electric heating element 100 is a three-core heating wire. The three-core heating wire includes an insulating protective wire sheath 104 and a first heating electric wire 101, a second heating electric wire 102, and a third heating electric wire 103 that are insulated from each other and wound around each other inside the insulating protective wire sheath 104.

[0041] Please refer to Figure 2 , which is a schematic structural connection diagram of a power supply circuit in an embodiment. The heat preservation bag further includes a power supply circuit 200, which is used to provide electrical energy for the heating source of the heat preservation bag when externally connected to an AC power supply or a DC power supply. The power supply circuit 200 includes an AC power supply circuit 201 and a DC power supply circuit 202. The heating source of the heat preservation bag is the flexible cable type electric heating element 100, and the flexible cable type electric heating element 100 includes a first heating electric wire L10, a second heating electric wire L20, and a third heating electric wire L30.

[0042] The AC power supply circuit 201 is electrically connected to the first heating electric wire L10. When the AC power supply circuit 201 is externally connected to an AC power supply, it converts the AC power supply into a first direct current and outputs it to the first heating electric wire, so as to use the first direct current as the heating power supply of the first heating electric wire. The DC power supply circuit 202 is respectively electrically connected to the second heating electric wire L20 and the third heating electric wire L30. When the DC power supply circuit 202 is externally connected to a DC power supply, it outputs the DC power supply to the second heating electric wire L20 or the third heating electric wire L30 to provide a heating power supply for the second heating electric wire L20 or the third heating electric wire L30. Among them, the externally connected DC power supply is a first DC power supply or a second DC power supply, and the supply voltage of the first DC power supply is less than the supply voltage of the second DC power supply. In one embodiment, the supply voltage of the first DC power supply is 12 volts. In one embodiment, the supply voltage of the second DC power supply is 24 volts. When the DC power supply circuit 202 is externally connected to the first DC power supply, the DC power supply circuit 202 uses the first DC power supply as the heating power supply of the second heating electric wire L20. When the DC power supply circuit 202 is externally connected to the second DC power supply, the DC power supply circuit 202 uses the second DC power supply as the heating power supply of the third heating electric wire L30. When the first heating electric wire L10, the second heating electric wire L20, and the third heating electric wire L30 are respectively used as the heating sources of the heat preservation bag, their respective heat output powers are the same.

[0043] In one embodiment, the external AC power supply is the first AC power supply or the second AC power supply, and the supply voltage of the first AC power supply is greater than that of the second AC power supply. In one embodiment, the supply voltage of the first AC power supply is 230 volts. In one embodiment, the supply voltage of the second AC power supply is 120 volts. When the AC power supply circuit 201 is externally connected to the first AC power supply or the second AC power supply, the first AC power supply or the second AC power supply is converted into the first direct current and then output to the first heating electric wire L10, and the first direct current is used as the heating power supply of the first heating electric wire.

[0044] Please refer to Figure 3 , which is a schematic circuit connection diagram of the power supply circuit in one embodiment. 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 to the positive output end of the external AC power supply, and the AC negative connection end of the AC connection circuit 10 is used to connect to the negative output end of the external AC power supply. The AC output end of the AC connection circuit 10 is connected to the first reference voltage acquisition circuit 11, the first switching circuit 14, and the first comparison circuit 12, and is used to output the electric energy 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.

[0045] 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 to 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 to the first comparison circuit 12 and the first switching circuit 14. The first reference voltage acquisition circuit 11 is used to convert the electric energy of the AC power supply into a first reference voltage source VC1 with a direct current and 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.

[0046] The first comparison circuit 12 includes an AC power input terminal, a reference power input terminal, and a comparison result output terminal. The AC power input terminal of the first comparison circuit 12 is connected to the AC output terminal of the AC connection circuit 10. The reference power input terminal of the first comparison circuit 12 is connected to the reference voltage output terminal of the first reference voltage acquisition circuit 11. The comparison result output terminal of the first comparison circuit 12 is connected to the first control circuit 13. The first comparison circuit 12 is configured to convert the electrical energy of the AC power supply into a DC first sampling voltage source, compare the voltage magnitudes of the first sampling voltage source and the first reference voltage source VC1, and output a first result electrical signal to the first control circuit 13 according to the comparison result. When the AC power supply circuit 201 is externally connected to the first AC power supply, the first result electrical signal is a high-level signal. When the AC power supply circuit 201 is externally connected to the second AC power supply, the first result electrical signal is a low-level signal.

[0047] The first control circuit 13 includes a comparison signal input terminal and a control signal output terminal. The comparison signal input terminal of the first control circuit 13 is connected to the comparison result output terminal of the first comparison circuit 12. The control signal output terminal of the first control circuit 13 is connected to the first switching circuit 14. The first control circuit 13 is configured to output a grounded pull-down signal to the first switching circuit 14 according to the first result electrical signal. When the first result electrical signal is a high-level signal, the control signal output terminal is grounded. When the first result electrical signal is a low-level signal, the control signal output terminal is made open.

[0048] The first switching circuit 14 includes a control signal input terminal, a reference voltage connection terminal, an AC power input terminal, and a thermal energy power output terminal. The control signal input terminal of the first switching circuit 14 is connected to the control signal output terminal of the first control circuit 13. The reference voltage connection terminal of the first switching circuit 14 is connected to the reference voltage output terminal of the first reference voltage acquisition circuit 11. The AC power input terminal of the first switching circuit 14 is connected to the AC output terminal of the AC connection circuit 10. The thermal energy power output terminal of the first switching circuit 14 is electrically connected to the first heating electric wire L10. The first switching circuit 14 is configured to convert the first AC power input from the AC power input terminal into a first direct current when the control signal input terminal is grounded, and output the converted first direct current to the first heating electric wire L10 through the thermal energy power output terminal. The first switching circuit 14 is further configured to convert the second AC power input from the AC power input terminal into a first direct current when the control signal input terminal is made open, and output the converted first direct current to the first heating electric wire L10 through the thermal energy power output terminal.

[0049] In one embodiment, the AC connection circuit 10 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 to the positive AC connection end of the AC connection circuit 10, and 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 connection is connected to the negative AC connection end of the AC connection circuit 10, and the other end of the series connection is connected to the AC output end of the AC connection circuit 10.

[0050] In one embodiment, the first reference voltage acquisition circuit 11 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 to the reference voltage output end of the first reference voltage acquisition circuit 11, and 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, and 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 connection is connected to the negative electrode of the second diode D12, and the other end of the series connection is connected to the first AC input end of the first reference voltage acquisition circuit 11.

[0051] In one embodiment, the first comparison circuit 12 further includes 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 sequence. One end of the series connection is connected to the AC power input end of the first comparison circuit 12, and the other end of the series connection is connected to the positive input end of the first comparator T1. One end of the fourth resistor R23 is grounded, and 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 input end of the first comparison circuit 12, and the other end is connected to the negative input end of the first comparator T1. One end of the sixth resistor R25 is grounded, and 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.

[0052] In one embodiment, the first control circuit 13 further includes a seventh resistor R31, an eighth resistor R32, and a triode Q1. One end of the seventh resistor R31 is grounded, and the other end is connected to the comparison signal input terminal of the first control circuit 13. One end of the eighth resistor R32 is connected to the comparison signal input terminal of the first control circuit 13, and the other end is connected to the base of the triode Q1. The emitter of the triode Q1 is grounded, and the collector of the triode Q1 is connected to the control signal output terminal of the first control circuit 13.

[0053] In one embodiment, the first switching circuit 14 further includes 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 terminal of the first switching circuit 14, and the other end is connected to the first electronic switch U1. Both ends of the fifth diode D42 are connected to the first electronic switch U1. The positive connection terminal of the fourth diode D41 is connected to the first electronic switch U1 and the AC power input terminal of the first switching circuit 14, and the negative connection terminal of the fourth diode D41 is connected to the thermal energy power output terminal of the first switching circuit 14 and the first electronic switch U1. The first electronic switch U1 is configured to output the AC first power input from the AC power input terminal to the first heating electric wire L10 through the fourth diode D41 when the control signal input terminal is grounded. The first switching circuit 14 is further configured to output the AC second power input from the AC power input terminal to the first heating electric wire L10 through the first electronic switch U1 when the control signal input terminal is made empty.

[0054] In one embodiment, the DC power supply circuit 202 includes a DC 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 DC connection circuit 15 includes a DC positive connection terminal, a DC negative connection terminal, and a DC output terminal. The DC positive connection terminal of the DC connection circuit 15 is used to connect to the positive output terminal of an external DC power supply, the DC negative connection terminal of the DC connection circuit 15 is used to connect to the negative output terminal of the external DC power supply, and the DC output terminal of the DC connection circuit 15 is connected to the second reference voltage acquisition circuit 16, the sampling circuit 17, the second comparison circuit 18, and the third comparison circuit 19 for outputting a DC power supply. The second reference voltage acquisition circuit 16 includes a power input terminal and a reference power output terminal. The power input terminal of the second reference voltage acquisition circuit 16 is connected to the DC output terminal of the DC connection circuit 15, and the reference power output terminal of the second reference voltage acquisition circuit 16 is connected to 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 DC 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 terminal. The sampling circuit 17 includes an input first connection terminal, an input second connection terminal, an output first connection terminal, an output second connection terminal, an output third connection terminal, and an output fourth connection terminal. The input first connection terminal of the sampling circuit 17 is connected to the DC output terminal of the DC connection circuit 15, the input second connection terminal of the sampling circuit 17 is connected to the reference power output terminal of the second reference voltage acquisition circuit 16, the output first connection terminal and the output second connection terminal of the sampling circuit 17 are connected to the second comparison circuit 18, and the output third connection terminal and the output fourth connection terminal of the sampling circuit 17 are connected to the third comparison circuit 19. The sampling circuit 17 is used to respectively perform voltage division sampling on the second reference voltage source and the DC power supply, and output the resulting electrical signals of the two voltage division samplings to the second comparison circuit 18 through the output first connection terminal and the output second connection terminal, and then output to the third comparison circuit 19 through the output third connection terminal and the output fourth connection terminal.

[0055] In one embodiment, the second comparison circuit 18 and the third comparison circuit 19 have the same circuit structure, and each includes a first comparison input terminal, a second comparison input terminal, and a DC power output terminal. The first comparison input terminal and the second comparison input terminal of the second comparison circuit 18 are respectively connected to the first output terminal and the second output terminal of the sampling circuit 17, and the first comparison input terminal and the second comparison input terminal of the third comparison circuit 19 are respectively connected to the third output terminal and the fourth output terminal of the sampling circuit 17. The DC power output terminal of the second comparison circuit 18 is connected to the second heating wire L20, and the DC power output terminal of the third comparison circuit 19 is connected to the third heating wire L30. The second comparison circuit 18 is configured to output the DC first power supply DC1 to the second heating wire L20 when the DC power supply is the DC first power supply DC1, so as to use the DC first power supply DC1 as the heating power supply of the second heating wire L20. The third comparison circuit 19 is configured to output the DC second power supply DC2 to the third heating wire L30 when the DC power supply is the DC second power supply DC2, so as to use the DC second power supply DC2 as the heating power supply of the third heating wire L30.

[0056] As Figure 3 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 positive electrode of the sixth diode D61 is connected to the power input terminal of the second reference voltage acquisition circuit 16, the negative electrode 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.

[0057] 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, and one end of the series connection is connected to the first input terminal of the sampling circuit 17, and the other end of the series connection is connected to the second output terminal and the third output terminal of the sampling circuit 17. One end of the eleventh resistor R72 is connected to the second input 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 terminal of the sampling circuit 17, and the other end is connected to the first output terminal and the fourth output terminal of the sampling circuit 17. One end of the thirteenth resistor R74 is connected to the first output terminal of the sampling circuit 17, and the other end is grounded.

[0058] In one embodiment, the second reference voltage acquisition circuit 16 further includes 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 to the reference power output terminal of the second reference voltage acquisition circuit 16, and the other end is grounded.

[0059] 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 triode Q2. One end of the fourteenth resistor R81 is connected to the output terminal of the second comparator T2, and the other end is connected to the base of the second triode Q2. One end of the fifteenth resistor R82 is connected to the base of the second triode Q2, and the other end is grounded. The emitter of the second triode Q2 is grounded, and the collector of the second triode 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 output terminal of the second reference voltage acquisition circuit 16. The second electronic switch U2 is also connected to the DC output terminal of the DC connection circuit 15.

[0060] 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 triode Q3. One end of the seventeenth resistor R91 is connected to the output terminal of the third comparator T3, and the other end is connected to the base of the third triode Q3. One end of the eighteenth resistor R92 is connected to the base of the third triode Q3, and the other end is grounded. The emitter of the third triode Q3 is grounded, and the collector of the third triode 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 output terminal of the second reference voltage acquisition circuit 16. The third electronic switch U3 is also connected to the DC output terminal of the DC connection circuit 15.

[0061] As Figure 2 shown, in one embodiment, the insulation bag further includes an interface adapter 300, which is used to electrically connect the AC power supply circuit 201 to an external AC power supply, and is also used to electrically connect the DC power supply circuit 202 to an external DC power supply. Among them, the interface adapter 300 can only be externally connected to one AC power supply or one DC power supply at the same time.

[0062] Please refer to Figure 4, which is a schematic diagram of the circuit connection of the power supply circuit in another embodiment. The AC power supply circuit 201 only supports connecting one external AC power supply, that is, the external AC power supply is the first AC 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, after being powered on, the first indicator LED1 is lit, and the first direct current obtained by converting the first AC power supply is used to heat through the first heating wire L10, and the temperature is controlled by the temperature controller. When the interface adapter is connected to the DC power supply (12V DC first power supply or 24V DC second power supply), after being stabilized by the DC conversion circuit Y1, a second reference voltage source of 9V is output. At this time, the second indicator LED2 is lit. The sampling circuit divides the 9V second reference voltage source through a resistor to obtain a comparison reference voltage of 3V, and outputs it 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 then divides the external DC power supply (12V or 24V). When the external power supply is the 12V DC first power supply, the divided voltage is 2.3V, and a comparison reference voltage of 2.3V is obtained; when the external power supply is the 24V DC second power supply, the divided voltage is 4.6V, and a comparison reference voltage of 4.6V is obtained; then the comparison reference voltages are respectively 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. Then when the DC power supply is the 12V DC first power supply, the second triode Q2 of the second comparison circuit conducts, and the second electronic switch U2 of the second comparison circuit outputs the 12V DC power supply DC1 to the second heating wire L20, and the DC first power supply heats through the second heating wire L20, and the temperature is controlled by the temperature controller. When the DC power supply is the 24V DC second power supply, the third triode Q3 of the third comparison circuit conducts, and the third electronic switch U3 of the third comparison circuit outputs the 24V DC power supply DC2 to the third heating wire L30, and the DC second power supply heats through the third heating wire L30, and the temperature is controlled by the temperature controller. The first heating wire L10, the second heating wire L20, and the third heating wire L30 do not interfere with each other, realizing the heating of three voltage sources (alternating current, DC first power supply, and DC second power supply) through a three-core heating wire. In an embodiment, the second electronic switch U2 and the third electronic switch U3 are relay switches.

[0063] Such as Figure 3As shown, in an embodiment of the present application, when the AC power supply connected to the interface adapter is 120V, the first reference voltage source obtained by the first reference voltage acquisition circuit is 11.3V. Then, the negative input terminal of the first comparator T1 obtains a comparison voltage of approximately 3.4V, and the positive input terminal of the first comparator T1 obtains a comparison voltage of 2.15V (divided by resistors R21, R22, and R23). At this time, the output terminal of the first comparator T1 outputs a low level, and the first triode Q1 turns off the first electronic switch U1 (in an embodiment, the first electronic switch U1 is a relay SW DPDT, and the normally closed state is when the relay is not attracted). The first electronic switch U1 causes the 120V alternating current not to pass through the fourth diode D41 but to be directly output to the first heating wire L10 to achieve heating. When the AC power supply connected to the interface adapter is 230V, the positive input terminal of the first comparator T1 obtains a comparison voltage of 4.13V. At this time, the output terminal of the first comparator T1 outputs a high level, the first triode Q1 conducts, and the first electronic switch U1 (relay SW DPDT) disconnects. The 230V alternating current forms a power supply circuit for the first heating wire L10 through the fourth diode D41 to achieve heating through the first heating wire L10. In the power supply circuit as shown in Figure 3 Four external power supplies (120V or 230V alternating current, 12V or 24V direct current) are enabled to generate heat through a three-core heating wire without interfering with each other. By 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 supplies are ensured to be consistent.

[0064] The flexible cord-type heating element disclosed in the embodiment of the present application is a three-core heating wire, including an insulating protective wire sheath and the first, second, and third heating wires that are insulated from each other and wound around each other within the insulating protective wire sheath. When the power supply of the heat preservation bag is an AC power supply, the first heating wire is used as the heating source. When the power supply of the heat preservation bag is a first DC power supply or a second DC power supply with different voltage values, the second heating wire or the third heating wire is used as the heating source. Since the thermal energy output powers of the first, second, and third heating wires are the same, the heat preservation bag supports different external power supplies and can maintain the same heat preservation effect under different external power supply conditions.

[0065] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the technical field to which the present invention belongs, based on the idea of the present invention, several simple deductions, deformations, or substitutions can also be made.

Claims

1. A soft cord type electric heating element for a thermal insulation bag, which is used as a heating source of the thermal insulation bag, and is characterized in that The flexible cable type electric heating element is a three-core heating wire, and the three-core heating wire includes an insulating protective wire sheath and a first heating electric wire, a second heating electric wire, and a third heating electric wire that are respectively insulated and wound around each other inside the insulating protective wire sheath; When the power supply of the heat preservation bag is an alternating current power supply, the first heating electric wire serves as the heating source of the heat preservation bag; when the power supply of the heat preservation bag is a direct current power supply, the second heating electric wire or the third heating electric wire serves as the heating source of the heat preservation bag; wherein, the direct current power supply includes a first direct current power supply and a second direct current power supply, and the supply voltage of the first direct current power supply is less than the supply voltage of the second direct current power supply; when the power supply of the heat preservation bag is the first direct current power supply, the second heating electric wire serves as the heating source of the heat preservation bag, and when the power supply of the heat preservation bag is the second direct current power supply, the third heating electric wire serves as the heating source of the heat preservation bag; When the first heating electric wire, the second heating electric wire, and the third heating electric wire respectively serve as the heating source of the heat preservation bag, their respective heat energy output powers are the same.

2. The flexible cord type electric heating element according to claim 1, characterized in that, The first heating electric wire, the second heating electric wire, and the third heating electric wire have the same length.

3. A thermal insulation bag, characterized in that, It includes a power supply circuit and the flexible cable type electric heating element according to any one of claims 1 to 2; The power supply circuit is used to provide electric energy for the heating source of the heat preservation bag when an alternating current power supply or a direct current power supply is externally connected; the power supply circuit includes an alternating current power supply circuit and a direct current power supply circuit; The alternating current power supply circuit is electrically connected to the first heating electric wire; when the alternating current power supply circuit is externally connected to the alternating current power supply, it converts the alternating current power supply into a first direct current and outputs it to the first heating electric wire to use the first direct current as the heating power supply of the first heating electric wire; The direct current power supply circuit is respectively electrically connected to the second heating electric wire and the third heating electric wire; when the direct current power supply circuit is externally connected to the direct current power supply, it outputs the direct current power supply to the second heating electric wire or the third heating electric wire to provide a heating power supply for the second heating electric wire or the third heating electric wire; wherein, the externally connected direct current power supply is the first direct current power supply or the second direct current power supply, and the supply voltage of the first direct current power supply is less than the supply voltage of the second direct current power supply; when the direct current power supply circuit is externally connected to the first direct current power supply, the direct current power supply circuit uses the first direct current power supply as the heating power supply of the second heating electric wire; when the direct current power supply circuit is externally connected to the second direct current power supply, the direct current power supply circuit uses the second direct current power supply as the heating power supply of the third heating electric wire.

4. The heat-insulating bag according to claim 3, wherein It further includes a bottom surface, a top surface, and four side surfaces, and the bottom surface, the top surface, and the four side surfaces enclose to form a closed space for heat preservation, and the bottom surface, the top surface, and the four side surfaces are respectively provided with heat preservation layers.

5. The heat-insulating bag according to claim 4, characterized in that, The bottom surface, the top surface, and / or the four side surfaces are also respectively provided with heating layers, and the flexible cable type electric heating element is wound around on the heating layers.

6. The heat-insulating bag according to claim 3, wherein It further includes an interface adapter, which is used for electrically connecting the AC power supply circuit to the external AC power supply, and also for electrically connecting the DC power supply circuit to the external DC power supply; wherein, the interface adapter can only externally connect to one of the AC power supplies or one of the DC power supplies at the same time.

7. The heat-insulating bag according to claim 3, characterized in that, The external AC power supply is the first AC power supply or the second AC power supply, and the supply voltage of the first AC power supply is greater than the supply voltage of the second AC power supply; When the AC power supply circuit externally connects to the first AC power supply or the second AC power supply, it converts the first AC power supply or the second AC power supply into the first direct current and outputs it to the first heating electric wire, and uses the first direct current as the heating DC power supply of the first heating electric wire.

8. The heat-insulating bag according to claim 7, 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 terminal, an AC negative connection terminal, and an AC output terminal; the AC positive connection terminal of the AC connection circuit is used to connect to the positive output terminal of the external AC power supply, and the AC negative connection terminal of the AC connection circuit is used to connect to the negative output terminal of the external AC power supply; the AC output terminal of the AC connection circuit is connected to 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 external 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 includes a first AC input terminal and a reference voltage output terminal. The first AC input terminal of the first reference voltage acquisition circuit is connected to the AC output terminal of the AC connection circuit, and the reference voltage output terminal of the first reference voltage acquisition circuit is connected to the first comparison circuit and the first switching circuit; the first reference voltage acquisition circuit is used to convert the electric energy of the AC power supply into a DC first reference voltage source with a preset voltage value, and output the first reference voltage source to the first comparison circuit and the first switching circuit through the reference voltage output terminal of the first reference voltage acquisition circuit; The first comparison circuit includes an AC electric energy input terminal, a reference power input terminal, and a comparison result output terminal; the AC electric energy input terminal of the first comparison circuit is connected to the AC output terminal of the AC connection circuit, the reference power input terminal of the first comparison circuit is connected to the reference voltage output terminal of the first reference voltage acquisition circuit, and the comparison result output terminal of the first comparison circuit is connected to the first control circuit; the first comparison circuit is used to convert the electric energy of the AC power supply into a DC first sampling voltage source, compare the voltage magnitudes of the first sampling voltage source and the first reference voltage source, and output a first result electrical signal to the first control circuit according to the comparison result; when the AC power supply circuit externally connects to the first AC power supply, the first result electrical signal is a high-level signal, and when the AC power supply circuit externally connects to the second AC power supply, the first result electrical signal is a low-level signal; The first control circuit includes a comparison signal input terminal and a control signal output terminal; the comparison signal input terminal of the first control circuit is connected to the comparison result output terminal of the first comparison circuit, and the control signal output terminal of the first control circuit is connected to the first switching circuit; the first control circuit is configured to output a pull-down signal to ground to the first switching circuit according to the first result electrical signal, and when the first result electrical signal is a high-level signal, ground the control signal output terminal, and when the first result electrical signal is a low-level signal, make the control signal output terminal open; The first switching circuit includes a control signal input terminal, a reference voltage connection terminal, an AC power input terminal, and a thermal energy power output terminal; the control signal input terminal of the first switching circuit is connected to the control signal output terminal of the first control circuit, the reference voltage connection terminal of the first switching circuit is connected to the reference voltage output terminal of the first reference voltage acquisition circuit, the AC power input terminal of the first switching circuit is connected to the AC output terminal of the AC connection circuit, and the thermal energy power output terminal of the first switching circuit is electrically connected to the first heating wire; the first switching circuit is configured to convert the first AC power input from the AC power input terminal into the first DC power when the control signal input terminal is grounded, and output the converted first DC power to the first heating wire through the thermal energy power output terminal; the first switching circuit is further configured to convert the second AC power input from the AC power input terminal into the first DC power when the control signal input terminal is open, and output the converted first DC power to the first heating wire through the thermal energy power output terminal.

9. The heat-insulating bag according to claim 7, wherein, The DC power supply circuit includes a DC connection circuit, a second reference voltage acquisition circuit, a sampling circuit, a second comparison circuit, and a third comparison circuit; The DC connection circuit includes a DC positive connection terminal, a DC negative connection terminal, and a DC output terminal; the DC positive connection terminal of the DC connection circuit is used to be connected to the positive output terminal of the external DC power supply, the DC negative connection terminal of the DC connection circuit is used to be connected to the negative output terminal of the external DC power supply, and the DC output terminal of the DC connection circuit is connected to the second reference voltage acquisition circuit, the sampling circuit, the second comparison circuit, and the third comparison circuit, and is configured to output the DC power supply; The second reference voltage acquisition circuit includes a power input terminal and a reference power output terminal, the power input terminal of the second reference voltage acquisition circuit is connected to the DC output terminal of the DC connection circuit, and the reference power output terminal of the second reference voltage acquisition circuit is connected to the sampling circuit, the second comparison circuit, and the third comparison circuit; the second reference voltage acquisition circuit is configured to convert the DC power supply into a second reference voltage source with a preset voltage value, and output the second reference voltage source through the reference power output terminal; The sampling circuit includes an input first connection terminal, an input second connection terminal, an output first connection terminal, an output second connection terminal, an output third connection terminal, and an output fourth connection terminal; the input first connection terminal of the sampling circuit is connected to the DC output terminal of the DC connection circuit, the input second connection terminal of the sampling circuit is connected to the reference power output terminal of the second reference voltage acquisition circuit, the output first connection terminal and the output second connection terminal of the sampling circuit are connected to the second comparison circuit, and the output third connection terminal and the output fourth connection terminal of the sampling circuit are connected to the third comparison circuit; the sampling circuit is used to perform voltage division sampling on the second reference voltage source and the DC power supply respectively, and output the resulting electrical signals of the two voltage division samplings to the second comparison circuit through the output first connection terminal and the output second connection terminal, and then output to the third comparison circuit through the output third connection terminal and the output fourth connection terminal; The circuit structures of the second comparison circuit and the third comparison circuit are the same, and each includes a first comparison input terminal, a second comparison input terminal, and a DC power output terminal; the first comparison input terminal and the second comparison input terminal of the second comparison circuit are respectively connected to the output first connection terminal and the output second connection terminal of the sampling circuit, the first comparison input terminal and the second comparison input terminal of the third comparison circuit are respectively connected to the output third connection terminal and the output fourth connection terminal of the sampling circuit, the DC power output terminal of the second comparison circuit is connected to the second heating electric wire, and the DC power output terminal of the third comparison circuit is connected to the third heating electric wire; the second comparison circuit is used to output the DC first power supply to the second heating electric wire when the DC power supply is the DC first power supply, so as to use the DC first power supply as the heating power supply of the second heating electric wire; the third comparison circuit is used to output the DC second power supply to the third heating electric wire when the DC power supply is the DC second power supply, so as to use the DC second power supply as the heating power supply of the third heating electric wire.

10. The heat-insulating bag according to claim 7, wherein, The supply voltage of the AC first power supply is 230V; the supply voltage of the AC second power supply is 120V; the supply voltage of the DC first power supply is 12V; the supply voltage of the DC second power supply is 24V.

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