Series-parallel switching circuit based on dual power supplies and dual loads and hair straightening equipment

Abstract

The invention provides a series-parallel connection switching circuit based on double power supplies and double loads and hair straightening equipment. The circuit comprises a heating module and a switch module. The heating module is connected with a first power supply, and the heating module is also used for being connected with a second power supply; the switch module is respectively connected with the first power supply and the heating module, and the switch module is also connected with a control module of the hair straightening equipment; wherein the switch module controls the first power supply to supply power to the heating module or controls the second power supply to supply power to the heating module under the control of the control module. The hair straightening equipment can give consideration to battery power supply and commercial power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of hair straightening equipment, and in particular to a series-parallel switching circuit based on dual power supplies and dual loads and a hair straightening equipment. Background Art

[0002] Hair straightening devices, such as hair straightening combs, can change the shape of hair by high temperature to achieve the purpose of straightening hair. Currently, commonly used hair straightening combs are mainly divided into two categories according to their power supply, one is AC power supply and the other is battery power supply. For AC power-powered hair straightening combs, they need to be connected to the AC power through a power cord, which is not convenient to carry. For battery-powered hair straightening combs, although they have a certain degree of portability, when the battery is out of power, it takes a long time to charge and cannot be used at any time. Therefore, there is currently no hair straightening comb that is both battery-powered and AC-powered. Summary of the invention

[0003] The present invention provides a series-parallel switching circuit and a hair straightening device based on dual power supplies and dual loads, aiming to solve the problem that the current hair straightening device cannot be powered by both batteries and AC power.

[0004] In a first aspect, the present invention provides a series-parallel switching circuit based on dual power supplies and dual loads, which is applied to a hair straightening device, and the circuit includes a heating module and a switch module; the heating module is connected to a first power supply, and the heating module is also used to be connected to a second power supply; the switch module is respectively connected to the first power supply and the heating module, and the switch module is also connected to a control module of the hair straightening device; wherein, under the control of the control module, the switch module controls the first power supply to power the heating module or controls the second power supply to power the heating module.

[0005] Further, the heating module includes a first heating element and a second heating element; one end of the first heating element and one end of the second heating element are both connected to the first power supply through the switch module, the other end of the first heating element is connected to the switch module, and the other end of the second heating element is connected to the switch module; wherein the first heating element is also used to connect to the second power supply.

[0006] Furthermore, the switch module includes a first switch circuit and a second switch circuit; one end of the first switch circuit is connected to the first power supply, the other end of the first switch circuit is respectively connected to the first heating element and the second heating element, and the first switch circuit is also connected to the control module; the second switch circuit is respectively connected to the first heating element, the second heating element and the control module.

[0007] Further, the first switching circuit includes a first switching element and a second switching element; one end of the first switching element is connected to the first power supply, the other end of the first switching element is connected to one end of the second switching element, the other end of the second switching element is respectively connected to the first heating element and the second heating element, and the controlled ends of the first switching element and the second switching element are also connected to the control module.

[0008] Furthermore, the second switch circuit comprises a third switch element, one end of the third switch element is connected to the first heating element, the other end of the third switch element is grounded, and the controlled end of the third switch element is also connected to the control module.

[0009] Furthermore, the second switch circuit further comprises a fourth switch element, one end of the fourth switch element is connected to the second heating element, the other end of the fourth switch element is grounded, and a controlled end of the fourth switch element is also connected to the control module.

[0010] Furthermore, it also includes a third switch circuit, which is connected in parallel with the third switch element and is also connected to the control module.

[0011] Furthermore, the third switch circuit includes a fifth switch element, one end of the fifth switch element is connected to the control module, and the other end of the fifth switch element is grounded.

[0012] Furthermore, both the first heating element and the second heating element are heating films.

[0013] In a second aspect, the present invention provides a hair straightening device, comprising a control module and any one of the above series-parallel switching circuits based on dual power supplies and dual loads.

[0014] The present invention discloses a series-parallel switching circuit based on dual power supplies and dual loads and a hair straightening device. The hair straightening device comprises a series-parallel switching circuit based on dual power supplies and dual loads and a control module. The series-parallel switching circuit based on dual power supplies and dual loads comprises a heating module and a switch module. The heating module is respectively connected to a first power supply and a second power supply. The first power supply may be a mains supply, and the second power supply may be a battery. Meanwhile, the switch module is respectively connected to the first power supply, the second power supply, the heating module and the control module. Under the control of the control module, it can be controlled whether the first power supply supplies power to the heating module or the second power supply supplies power to the heating module, so that it can switch between being powered by the first power supply and being powered by the second power supply, thereby enabling the hair straightening device to be powered by both the battery and the mains supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0016] Figure 1 is a block diagram of a series-parallel switching circuit based on dual power supplies and dual loads provided by a first embodiment of the present invention;

[0017] Figure 2 is a block diagram of a series-parallel switching circuit based on dual power supplies and dual loads provided by a second embodiment of the present invention;

[0018] Figure 3 is a block diagram of a series-parallel switching circuit based on dual power supplies and dual loads provided in a third embodiment of the present invention;

[0019] Figure 4 It is a circuit diagram of a series-parallel switching circuit based on dual power supplies and dual loads provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, operations, elements, components and / or groups thereof.

[0022] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, the singular forms of "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0023] In addition, the directional terms mentioned in the present invention, such as "upper", "lower", "front", "back", "left", "right", "inner", "outer", "side", etc., are only for reference to the directions of the attached drawings and the use status of the product. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention. In addition, in the drawings, structures with similar or identical structures are represented by the same reference numerals.

[0024] See also Figures 1 to 4 , Figure 1 is a block diagram of a series-parallel switching circuit 100 based on dual power supplies and dual loads provided in a first embodiment of the present invention; Figure 2 is a block diagram of a series-parallel switching circuit 100 based on dual power supplies and dual loads provided in a second embodiment of the present invention; Figure 3 is a block diagram of a series-parallel switching circuit 100 based on dual power supplies and dual loads provided in a third embodiment of the present invention; Figure 4 FIG. 1 is a circuit diagram of a series-parallel switching circuit 100 based on dual power supplies and dual loads provided by an embodiment of the present invention. Figure 1 As shown, the series-parallel switching circuit 100 based on dual power supplies and dual loads provided by the present invention includes a heating module 10 and a switch module 20; the heating module 10 is connected to a first power supply 200, and the heating module 10 is also used to be connected to a second power supply 300; the switch module 20 is respectively connected to the first power supply 200 and the heating module 10, and the switch module 20 is also connected to the control module of the hair straightening device; wherein, the switch module 20 controls the first power supply 200 to power the heating module 10 or controls the second power supply 300 to power the heating module 10 under the control of the control module.

[0025] Specifically, the hair straightening device may be a hair straightening comb, a hair straightening clip, a hair straightening rod, a hair straightener, etc., which may include a control module and a series-parallel switching circuit 100 based on dual power supplies and dual loads. The control module may include an MCU for controlling the operation of the hair straightening device. At the same time, the control module is also connected to the series-parallel switching circuit 100 based on dual power supplies and dual loads, and may control whether the first power supply 200 supplies power to the series-parallel switching circuit 100 based on dual power supplies and dual loads or the second power supply 300 supplies power to the series-parallel switching circuit 100 based on dual power supplies and dual loads.

[0026] The first power supply 200 may be a lithium battery, which is arranged in the hair straightening device, and the second power supply 300 may be a power adapter, which is connected to the hair straightening device and the mains respectively. Generally, the hair straightening device is not connected to the second power supply 300, and the hair straightening device is powered by the first power supply 200. When the hair straightening device is connected to the second power supply 300, the control module detects that the hair straightening device is connected to the second power supply 300, and controls the series-parallel switching circuit 100 based on dual power supplies and dual loads to switch to the second power supply 300 for power supply. At this time, the first power supply 200 does not supply power, and the second power supply 300 supplies power instead.

[0027] The series-parallel switching circuit 100 based on dual power supplies and dual loads may include a heating module 10 and a switch module 20. The heating module 10 is used to provide heat energy to increase the temperature of the hair straightening device, so that the hair straightening device can perform hair straightening. The heating module 10 is connected to the first power supply 200, and the heating module 10 is also used to connect to the second power supply 300. Generally, the heating module 10 is powered by the first power supply 200. When the second power supply 300 is connected, the heating module 10 is connected to the second power supply 300 and is powered by the second power supply 300.

[0028] The switch module 20 is connected to the first power supply 200 and the heating module 10 respectively. At the same time, the switch module 20 is also connected to the control module and can perform corresponding actions under the control of the control module. When the second power supply 300 is not connected, the heating module 10 is connected to the first power supply 200 through the switch module 20. At this time, the control module controls the switch module 20 to be turned on, and the first power supply 200 supplies power to the heating module 10. When the second power supply 300 is connected, the control module disconnects the connection between the first power supply 200 and the heating module 10 through the switch module 20, the first power supply 200 stops supplying power to the heating module 10, and the second power supply 300 starts supplying power to the heating module 10.

[0029] As a further embodiment, the heating module 10 includes a first heating element 11 and a second heating element 12; one end of the first heating element 11 and one end of the second heating element 12 are both connected to the first power supply 200 through the switch module 20, the other end of the first heating element 11 is connected to the switch module 20, and the other end of the second heating element 12 is connected to the switch module 20; wherein the first heating element 11 is also used to connect to the second power supply 300. As a further embodiment, the first heating element 11 and the second heating element 12 are both heating films.

[0030] The heating module 10 may include a first heating element 11 and a second heating element 12, and the first heating element 11 and the second heating element 12 may both be heating films. One end of the first heating element 11 and the second heating element 12 are both connected to the first power supply 200 through the switch module 20, and at the same time, the other ends of the first heating element 11 and the second heating element 12 are also connected to the switch module 20, that is, the switch module 20 may include two parts, the first part is the first module, and the second part is the second module, then one end of the first heating element 11 and the second heating element 12 are connected to the first power supply 200 through the first module, and the other ends of the first heating element 11 and the second heating element 12 are connected to the second module, and at the same time, the first heating element 11 is also connected to the second power supply 300.

[0031] When the first module is turned on under the control of the control module, the first power supply 200 supplies power to the first heating element 11 and the second heating element 12 through the first module, and the first heating element 11 and the second heating element 12 work normally. At this time, the control module can control the conduction state of the second module to connect the first element and the second element in parallel. When the control module detects that the second power supply 300 is connected, the control module controls the first module and the second module to be disconnected, and controls the on and off of the second module to connect the first heating element 11 and the second heating element 12 in series. At this time, the second power supply 300 supplies power to the first heating element 11 and the second heating element 12.

[0032] As a further embodiment, the switch module 20 includes a first switch circuit 21 and a second switch circuit 22; one end of the first switch circuit 21 is connected to the first power supply 200, and the other end of the first switch circuit 21 is respectively connected to the first heating element 11 and the second heating element 12, and the first switch circuit 21 is also connected to the control module; the second switch circuit 22 is respectively connected to the first heating element 11, the second heating element 12 and the control module.

[0033] The first switch circuit 21 is the aforementioned first module, and the second switch circuit 22 is the aforementioned second module. The first switch circuit 21 is connected to the first switch power supply, the first heating element 11, and the second heating element 12, respectively, to control the on-off between the first power supply 200 and the first heating element 11 and the second heating element 12. The second switch circuit 22 is connected to the first heating element 11 and the second heating element 12, respectively, to control the first heating element 11 and the second heating element 12 to be connected in series or in parallel.

[0034] When the first switch circuit 21 is turned on, the first power supply 200 supplies power to the first heating element 11 and the second heating element 12. At this time, the first heating element 11 and the second heating element 12 are connected in parallel. When the control module detects that the second power supply 300 is connected, the first switch circuit 21 is disconnected, and the second power supply 300 supplies power to the first heating element 11 and the second heating element 12. At this time, the first heating element 11 and the second heating element 12 are connected in series.

[0035] As a further embodiment, the first switching circuit 21 includes a first switching element Q1 and a second switching element Q2; one end of the first switching element Q1 is connected to the first power supply 200, the other end of the first switching element Q1 is connected to one end of the second switching element Q2, the other end of the second switching element Q2 is respectively connected to the first heating element 11 and the second heating element 12, and the controlled ends of the first switching element Q1 and the second switching element Q2 are also connected to the control module.

[0036] The first switch circuit 21 may include a first switch element Q1 and a second switch element Q2, one end of the first switch element Q1 is connected to the first power supply 200, the other end of the first switch element Q1 is connected to one end of the second switch element Q2, the other end of the second switch element Q2 is connected to the first heating element 11 and the second heating element 12 respectively, and the controlled ends of the first switch element Q1 and the second switch element Q2 are also connected to the control module. Preferably, both the first switch element Q1 and the second switch element Q2 may be PMOS tubes, such as Figure 4 As shown, the first switching element Q1 may be a first PMOS tube Q1, and the second switching element Q2 may be a second PMOS tube Q2, then the source of the first PMOS tube Q1 is connected to the first power supply 200, the drain of the first PMOS tube Q1 is connected to the source of the second PMOS tube Q2, the drain of the second PMOS tube Q2 is connected to the first heating element 11 and the second heating element 12 respectively, and at the same time, the gates of the first PMOS tube Q1 and the second PMOS tube Q2 are also connected to the control module.

[0037] The control module can control the first PMOS tube Q1 and the second PMOS tube Q2 to be turned on and off at the same time. When the first PMOS tube Q1 and the second PMOS tube Q2 are turned on at the same time, the first power supply 200 supplies power to the first heating element 11 and the second heating element 12. When the first PMOS tube Q1 and the second PMOS tube Q2 are turned off at the same time, the first power supply 200 stops supplying power to the first heating element 11 and the second heating element 12.

[0038] As a further embodiment, the second switch circuit 22 includes a third switch element Q3, one end of the third switch element Q3 is connected to the first heating element 11, the other end of the third switch element Q3 is grounded, and the controlled end of the third switch element Q3 is also connected to the control module. As a further embodiment, the second switch circuit 22 also includes a fourth switch element Q4, one end of the fourth switch element Q4 is connected to the second heating element 12, the other end of the fourth switch element Q4 is grounded, and the controlled end of the fourth switch element Q4 is also connected to the control module.

[0039] The second switch circuit 22 may include a third switch element Q3 and a fourth switch element Q4, one end of the third switch element Q3 is connected to the first heating element 11, one end of the fourth switch element Q4 is connected to the second heating element 12, and the other ends of the third switch element Q3 and the fourth switch element Q4 are both grounded, and the controlled ends of the third switch element Q3 and the fourth switch element Q4 are also connected to the control module. Preferably, the third switch element Q3 and the fourth switch element Q4 are both NMOS tubes, such as Figure 4 As shown, the third switch element Q3 can be a third NMOS tube Q3, and the fourth switch element Q4 can be a third NMOS tube Q3, then the drain of the third NMOS tube Q3 is connected to the first heating element 11, the source of the third NMOS tube Q3 is grounded, the drain of the fourth NMOS tube Q4 is connected to the second heating element 12, the source of the fourth NMOS tube Q4 is grounded, and the gates of the third NMOS tube Q3 and the fourth NMOS tube Q4 are both connected to the control module, that is, the third NMOS tube Q3 is connected to Heart2, and the fourth NMOS tube Q4 is connected to Heart1, wherein Heart2 and Heart1 are pins of the MCU in the control module.

[0040] exist Figure 4In the embodiment, T1 is the first heating element 11, T2 is the second heating element 12, and the resistance values ​​of T1 and T2 are both 1.5Ω. When the first power supply 200 supplies power, the first PMOS tube Q1 and the second PMOS tube Q2 are both turned on, and the third NMOS tube Q3 and the fourth NMOS tube Q4 are also turned on. At this time, T1 and T2 are connected in parallel, and the resistance value after parallel connection is 0.75Ω. If the supply voltage of the first power supply 200 is 8.4V, when the first power supply 200 supplies power, the power is 8.4V*8.4V / 0.75Ω=94W, and the hair straightening device is heated at a power of 94W. When the hair straightening device reaches a predetermined temperature, the temperature of the hair straightening device can be maintained at a predetermined temperature by controlling the on and off of the first PMOS tube Q1 and the second PMOS tube Q2. When the second power supply 300 is connected, the first PMOS tube Q1 and the second PMOS tube Q2 are disconnected, the third NMOS tube Q3 and the fourth NMOS tube Q4 are disconnected, and the control module then turns on the fourth NMOS tube Q4 alone. At this time, T1 and T2 are connected in series. If the rated voltage of the second power supply 300 is 15V and the rated current is 5A, the power is 15V*5A=75W. The hair straightening device is heated at a power of 75W, and the temperature can be maintained at a predetermined temperature by controlling the on and off of the fourth NMOS tube Q4.

[0041] As a further embodiment, the third switch circuit 30 is further included, the third switch circuit 30 is connected in parallel with the third switch element Q3, and the third switch circuit 30 is also connected to the control module. As a further embodiment, the third switch circuit 30 includes a fifth switch element Q5, one end of the fifth switch element Q5 is connected to the control module, and the other end of the fifth switch element Q5 is grounded.

[0042] Among them, the third switching circuit 30 may include a fifth switching element Q5, and the fifth switching element Q5 may be a controllable switch, which is connected to the control module. When the second power supply 300 is connected, the controllable switch is turned on, and the voltage of the third switching element Q3 is pulled down to avoid the third switching element Q3 from being turned on, thereby preventing the second power supply 300 from being short-circuited.

[0043] The present invention also provides a hair straightening device, which includes a control module and a series-parallel switching circuit 100 based on dual power supplies and dual loads according to any one of the above embodiments, wherein the series-parallel switching circuit 100 based on dual power supplies and dual loads includes a heating module 10 and a switch module 20; the heating module 10 is connected to a first power supply 200, and the heating module 10 is also used to be connected to a second power supply 300; the switch module 20 is respectively connected to the first power supply 200 and the heating module 10, and the switch module 20 is also connected to the control module of the hair straightening device; wherein, under the control of the control module, the switch module 20 controls the first power supply 200 to supply power to the heating module 10 or controls the second power supply 300 to supply power to the heating module 10.

[0044] Specifically, the hair straightening device may be a hair straightening comb, a hair straightening clip, a hair straightening rod, a hair straightener, etc., which may include a control module and a series-parallel switching circuit 100 based on dual power supplies and dual loads. The control module may include an MCU for controlling the operation of the hair straightening device. At the same time, the control module is also connected to the series-parallel switching circuit 100 based on dual power supplies and dual loads, and may control whether the first power supply 200 supplies power to the series-parallel switching circuit 100 based on dual power supplies and dual loads or the second power supply 300 supplies power to the series-parallel switching circuit 100 based on dual power supplies and dual loads.

[0045] The first power supply 200 may be a lithium battery, which is arranged in the hair straightening device, and the second power supply 300 may be a power adapter, which is connected to the hair straightening device and the mains respectively. Generally, the hair straightening device is not connected to the second power supply 300, and the hair straightening device is powered by the first power supply 200. When the hair straightening device is connected to the second power supply 300, the control module detects that the hair straightening device is connected to the second power supply 300, and controls the series-parallel switching circuit 100 based on dual power supplies and dual loads to switch to the second power supply 300 for power supply. At this time, the first power supply 200 does not supply power, and the second power supply 300 supplies power instead.

[0046] The series-parallel switching circuit 100 based on dual power supplies and dual loads may include a heating module 10 and a switch module 20. The heating module 10 is used to provide heat energy to increase the temperature of the hair straightening device, so that the hair straightening device can perform hair straightening. The heating module 10 is connected to the first power supply 200, and the heating module 10 is also used to connect to the second power supply 300. Generally, the heating module 10 is powered by the first power supply 200. When the second power supply 300 is connected, the heating module 10 is connected to the second power supply 300 and is powered by the second power supply 300.

[0047] The switch module 20 is connected to the first power supply 200 and the heating module 10 respectively. At the same time, the switch module 20 is also connected to the control module and can perform corresponding actions under the control of the control module. When the second power supply 300 is not connected, the heating module 10 is connected to the first power supply 200 through the switch module 20. At this time, the control module controls the switch module 20 to be turned on, and the first power supply 200 supplies power to the heating module 10. When the second power supply 300 is connected, the control module disconnects the connection between the first power supply 200 and the heating module 10 through the switch module 20, the first power supply 200 stops supplying power to the heating module 10, and the second power supply 300 starts supplying power to the heating module 10.

[0048] The series-parallel switching circuit and direct-transmission device based on dual power supplies and dual loads disclosed in the present invention, when the system current is detected, controls the charging of the first preset set or controls the discharging of the second preset set according to the current type of the system current, and when a new battery pack is detected, re-divides the set to obtain a new first preset set and a new second preset set, so that the new battery pack can be connected in parallel while continuing to charge or discharge, thereby supporting hot-swappable parallel connection.

[0049] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A series-parallel switching circuit based on dual power supplies and dual loads, characterized in that: Applied to hair straightening equipment, the circuit comprises: A heating module, the heating module is connected to the first power supply, and the heating module is also used to be connected to the second power supply; A switch module, the switch module is connected to the first power supply and the heating module respectively, and the switch module is also connected to the control module of the hair straightening device; Wherein, under the control of the control module, the switch module controls the first power supply to supply power to the heating module or controls the second power supply to supply power to the heating module.

2. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 1, characterized in that: The heating module comprises a first heating element and a second heating element; One end of the first heating element and one end of the second heating element are both connected to the first power supply through the switch module, the other end of the first heating element is connected to the switch module, and the other end of the second heating element is connected to the switch module; Wherein, the first heating element is also used to be connected to the second power supply.

3. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 2, characterized in that: The switch module includes a first switch circuit and a second switch circuit; One end of the first switch circuit is connected to the first power supply, the other end of the first switch circuit is connected to the first heating element and the second heating element respectively, and the first switch circuit is also connected to the control module; The second switch circuit is connected to the first heating element, the second heating element and the control module respectively.

4. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 3, characterized in that: The first switch circuit includes a first switch element and a second switch element; One end of the first switch element is connected to the first power supply, the other end of the first switch element is connected to one end of the second switch element, the other end of the second switch element is connected to the first heating element and the second heating element respectively, and the controlled ends of the first switch element and the second switch element are also connected to the control module.

5. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 3, characterized in that: The second switch circuit includes a third switch element, one end of the third switch element is connected to the first heating element, the other end of the third switch element is grounded, and a controlled end of the third switch element is also connected to the control module.

6. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 5, characterized in that: The second switch circuit further includes a fourth switch element, one end of the fourth switch element is connected to the second heating element, the other end of the fourth switch element is grounded, and a controlled end of the fourth switch element is also connected to the control module.

7. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 5, characterized in that: It also includes a third switch circuit, which is connected in parallel with the third switch element and is also connected to the control module.

8. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 7, characterized in that: The third switch circuit includes a fifth switch element, one end of the fifth switch element is connected to the control module, and the other end of the fifth switch element is grounded.

9. The series-parallel switching circuit based on dual power supplies and dual loads as claimed in claim 2, characterized in that: The first heating element and the second heating element are both heating films.

10. A hair straightening device, characterized in that: It comprises a control module and a series-parallel switching circuit based on dual power supplies and dual loads as described in any one of claims 1 to 9.

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