Hair styling device with reconfigurable current

Abstract

A hair styling device has a heating element and a sensor for determining a voltage and / or current output of an electrical energy source and outputting a signal indicative of the determined voltage and / or current output. The switch component is connected with the heating element. The switching component is controlled to reconfigure the current flowing through the plurality of heating elements according to the signal.

Description

Technical Field

[0001] The present invention relates to a hair styling device that utilizes heat and optionally moving air to dry and / or style hair. Background Art

[0002] Hair styling devices such as hair dryers and hair straighteners utilize heat to allow the user's hair to be styled. For example, a hair dryer heats the air that blows out of a nozzle and directs it onto the hair to be dried / styled. A hair straightener may heat one or more plates between which a strand of hair is drawn to be straightened.

[0003] It is desirable to be able to use a hair styling appliance in areas with different mains voltages. For example, a switch may allow a user to place the hair styling appliance in a low voltage (e.g., nominally 120 Vac) or high voltage (e.g., nominally 230 Vac) mode, depending on the local mains voltage. It is also desirable to be able to improve the operation of a battery-powered hair styling appliance even in the event of voltage fluctuations or reductions in the amount of electrical power available during operation. Summary of the invention

[0004] According to a first aspect of the present invention, there is provided a hair styling device comprising:

[0005] multiple heating elements;

[0006] a sensor for determining a voltage and / or current output of a source of electrical energy and outputting a signal indicative of the determined voltage and / or current output; and

[0007] one or more switch components connected to the heating element;

[0008] Therein, the hair styling appliance is configured such that the one or more switch components are controlled to reconfigure the current flowing through the plurality of heating elements at least in part dependent on the signal.

[0009] By reconfiguring the current flowing through the heating element in this manner, the possibility of user error in selecting the zone voltage can be reduced or eliminated. In addition, efficiency, safety and battery life can be improved despite voltage fluctuations or voltage drops of the electrical energy source during the energy source's operating cycle.

[0010] The sensor is configured to determine a voltage output, a current output, or a combination thereof, of the electrical energy source and output a signal indicative of the determined voltage and / or current output. This may be advantageous when limited information is available about the power actually consumed by the hair styling appliance. Monitoring the voltage output may provide information about power supply stability and device compatibility, while monitoring the current output may allow for direct and accurate assessment of power consumption, detection of faults, and implementation of protective measures. Thus, combined voltage and current output monitoring may provide a more complete understanding of the behavior of the electrical energy source.

[0011] The electrical energy source may include a mains power supply. Alternatively or additionally, the electrical energy source may include an electrical energy storage. The electrical energy source may be a battery, such as a rechargeable battery. The electrical energy source may replenish the electrical energy, such as by charging.

[0012] When the determined voltage is within the first voltage value range, one or more switch components can be controlled so that the total circuit resistance of the heating element through which the current flows is lower than the total circuit resistance of the heating element through which the current flows when the determined voltage exceeds the first voltage value range.

[0013] When the determined voltage is within a first voltage value range, one or more switch components may be controlled such that current flows in parallel through at least the first and second heating elements, thereby reducing a total circuit resistance of the heating elements through which the current flows.

[0014] When the determined voltage is within the first voltage value range, one or more switch components can be controlled so that current does not flow through at least one heating element other than the first and second heating elements, thereby reducing the total circuit resistance of the heating elements through which the current flows.

[0015] When the determined voltage is within a first voltage value range, one or more switch components may be controlled such that at least one heating element is bypassed, thereby reducing a total circuit resistance of the heating element through which current flows.

[0016] When the determined voltage is within the second voltage value range, one or more switch components can be controlled so that the total circuit resistance of the heating element through which the current flows is higher than the total circuit resistance of the heating element through which the current flows when the determined voltage is below the second voltage value range.

[0017] When the determined voltage is within the second voltage value range, the one or more switch components may be controlled so that current flows in series through at least the third and fourth heating elements, thereby increasing the total circuit resistance of the heating elements through which the current flows. The third and fourth heating elements may be the first and second heating elements, or either or both of the third and fourth heating elements may be additional elements to the first and second heating elements.

[0018] There may also be one or more additional heating elements connected in series and / or parallel with any one or more of the first, second, third and / or fourth heating elements, or a combination thereof.

[0019] When the determined voltage is within the second voltage value range, one or more switch components can be controlled so that current flows through at least one heating element, and when the determined voltage is outside the second voltage value range, current does not flow through the heating element.

[0020] When the determined voltage is within the second voltage value range, one or more switch components can be controlled so that current flows through at least one heating element, and when the determined voltage is lower than the second voltage value range, current does not flow through the heating element.

[0021] At least a plurality of heating elements may be connected in parallel with each other, each of the parallel-connected heating elements being controllable by at least one switch component, the hair styling appliance being configured to control the one or more switch components in response to the signal so as to configure current to flow through:

[0022] a first set of heating elements; or

[0023] A second set of heating elements is provided that is different from the first set.

[0024] The first set of heating elements may include one or more heating elements of the second set of heating elements.

[0025] The switching component may include one or more power semiconductor devices, one or more TRIACS, and / or one or more relays.

[0026] One or more switch components may be connected in series with at least one heating element.

[0027] The hair styling appliance may include a heater, wherein the heater includes a plurality of heating elements. In another example, the hair styling appliance may include a plurality of heaters, wherein each heater includes a corresponding plurality of heating elements. In embodiments including a plurality of heaters, each of the plurality of heaters may be controlled independently of one another. For example, in embodiments, the hair styling appliance may include a first heater and a second heater, each heater including a corresponding plurality of heating elements, and the hair styling appliance may be configured such that the first heater may be controlled independently of the second heater. By independently controlling each of the plurality of heaters, the hair styling appliance provides greater flexibility and versatility in use.

[0028] In an embodiment, wherein the hair styling appliance comprises a first heater and a second heater, each heater comprising a respective plurality of heating elements, the hair styling appliance may be configured to control one or more switch components to reconfigure current flowing through the plurality of heating elements such that power delivered to the first heater is different from power delivered to the second heater. By delivering different powers to the first heater and the second heater, the hair styling appliance provides greater flexibility and versatility in use.

[0029] In an embodiment, the hair styling appliance may be reconfigured so that the total circuit resistance of the heating elements of the first heater through which the current flows is different from the total circuit resistance of the heating elements of the second heater. In another embodiment, the hair styling appliance may be configured to control one or more switch components so that the current flows in parallel through at least the first and second heating elements of one of the first or second heaters, while the current flows in series through at least the first and second heating elements of the other of the first or second heaters. By configuring the respective heating elements of the first and second heaters in this manner, the hair styling appliance provides greater flexibility and versatility in use. Furthermore, this enables the heaters of the hair styling appliance to be controlled at different power levels under a common duty cycle of pulse width modulation, thereby reducing the number of components and the complexity of the circuit design.

[0030] In an embodiment, at least two of the plurality of heating elements may be connected to the switch component via a shared electrical connection. This provides the advantage of reducing the number of connection points and cables required, thereby reducing the overall power loss in the circuit. In battery-powered applications, this also increases the operating time. With the reduction in power loss, the control signal can keep the switch component in the on state for a longer time and with a relatively low peak current compared to an equivalent circuit design in which the first heating element and the second heating element do not share a common electrical connection. Therefore, the circuit design can be further simplified without any compromise, and with fewer connectors, more efficient use of available circuit space, and reduced manufacturing and assembly costs.

[0031] The hair styling appliance may comprise a controller connected to control the one or more switch components, wherein the controller is configured to receive the signal from the sensor.

[0032] The energy source may include a single cell. The energy source may include a plurality of cells, wherein the cells are interconnected, and the cells may be connected in series, in parallel, or a combination thereof. Each cell may be a lithium ion cell. The energy source may be a solid polymer battery pack.

[0033] The hair styling appliance may include a housing and the electrical energy source may be located within the housing. Providing the electrical energy source within the housing eliminates the need for an external power source which may undesirably make the hair styling appliance bulky and cumbersome to use.

[0034] The hair styling appliance may include an electrical connector that can be connected to an external power source to facilitate charging of the electrical energy source.

[0035] The hair styling appliance may include a charging circuit to control the flow of electrical energy from the electrical connector to the electrical energy source, thereby charging the electrical energy source.

[0036] When the electrical energy source can be charged via the electrical connector, no external cables need to be provided to power the heater or the heater of the hair styling appliance. This makes the use of the hair styling appliance of the present invention easier and more convenient. As a result, the user will feel more comfortable when operating the hair styling appliance.

[0037] The electrical energy source may include a lithium-ion battery. The battery may provide a voltage of 2.65V or more. The battery may provide a voltage of 50V or less. In some embodiments, the battery may provide a voltage of 26V or less. In some embodiments, the battery may provide a voltage of 17V or less. The capacity of the battery is at least 700mAh. The capacity of the battery is at least 1000mAh. The capacity of the battery is less than 40000mAh. In some embodiments, the capacity of the battery is less than 25000mAh. The continuous discharge current of the battery may be up to 40A. In another example, the continuous discharge rate of the battery may be up to 25A. In another example, the continuous discharge rate of the battery may be up to 10A. The battery may provide a continuous power in the range of 0.5W to 350W.

[0038] The hair styling appliance may include a processor to control the supply of electrical energy from the electrical energy source to the plurality of heating elements.

[0039] When the electrical energy source is a battery, potential problems may arise in relation to managing variations in battery cell voltage. Such variations may be a drop in battery cell voltage during operation of the hair styling device. For example, in an embodiment, the cell voltage may vary between 4.2 VDC when fully charged and 2.65 VDC when fully discharged. The present invention provides a hair styling device that is able to maintain acceptable performance at low battery cell voltages while avoiding excessive current at high battery cell voltages. This may also improve the life of the battery.

[0040] Advantageously, a thermal protection component having a lower rated peak current value may be selected for the control circuit. The heating element may be controlled by pulse width modulation (PWM), which in turn pulse width modulates the current flowing through the heating element. Since the thermal protection component monitors the current drawn from the energy source, the magnitude of the current flowing through the heating element becomes an important parameter in selecting a suitable thermal protection component. The pulsed nature of the power regulation also generates electromagnetic interference. The proposed reconfiguration of the switching component can limit the peak current flowing through the heater while maintaining the operation of the hair styling device despite changes in the energy source voltage. Limiting the peak current is also advantageous in selecting cheaper and simpler components, as it allows the use of components with lower peak current ratings and electromagnetic interference.

[0041] According to a second aspect of the present invention, a hair styling device kit is provided, comprising at least one hair styling device according to the first aspect of the present invention and a hair styling device charging device for charging the hair styling device. The charging device is configured to deliver electrical energy to the hair styling device to charge an electrical energy source.

[0042] A hair styling device is also provided, comprising:

[0043] a first heater and a second heater, each heater comprising a corresponding plurality of heating elements;

[0044] one or more switch components connected to the heating element;

[0045] The hair styling appliance is configured to control one or more switch components to reconfigure current flowing through the plurality of heating elements such that power delivered to a first heater is different from power delivered to a second heater.

[0046] The switch component of the hair styling appliance may further be reconfigured so that the total circuit resistance through which the heating element of the first heater flows is different from the total circuit resistance of the heating element of the second heater.

[0047] The switching components of one or both of the first and second heaters may be reconfigured so that current flows in parallel through at least the first and second heating elements, thereby reducing the overall circuit resistance of the first heating element through which the current flows.

[0048] The switching components of one or both of the first and second heaters may be reconfigured so that current flows in series through at least the first and second heating elements, thereby increasing the total circuit resistance of the heating elements through which the current flows.

[0049] The switch component of the hair styling appliance may further be reconfigured so that current flows in parallel through the first and second heating elements of at least one of the first or second heaters, and current flows in series through at least the first and second heating elements of the other of the first or second heaters.

[0050] The switch component may be controlled via a user interface. This enables selective operation of the heaters according to user preferences or application type. The switch component may be controlled by a controller comprising a set of machine-readable instructions. When the controller executes the machine-readable instructions, the instructions may reconfigure the hair styling appliance to control one or more switch components to reconfigure the current flowing through the plurality of heating elements such that the power provided to the first heater is different from the power provided to the second heater.

[0051] Also provided is a method of controlling a hair styling appliance, the hair styling appliance comprising:

[0052] multiple heating elements;

[0053] a sensor for determining a voltage and / or current output of a source of electrical energy and outputting a signal indicative of the determined voltage and / or current; and

[0054] one or more switch components connected to the heating element;

[0055] The method includes controlling one or more switching components to reconfigure current flow through a plurality of heating elements dependent at least in part on the signal.

[0056] When the determined voltage is within a first voltage value range, the method may include controlling one or more switching components so that a total circuit resistance of the heating element through which the current flows is lower than a total circuit resistance of the heating element through which the current flows when the determined voltage is outside the first voltage value range.

[0057] When the determined voltage is within a first voltage value range, the method may include controlling one or more switch components such that current flows in parallel through at least the first and second heating elements, thereby reducing a total circuit resistance of the heating elements through which the current flows.

[0058] When the determined voltage is within the first voltage value range, the method may include controlling one or more switching components so that current does not flow through at least one heating element other than the first and second heating elements, thereby reducing the total circuit resistance of the heating elements through which the current flows.

[0059] When the determined voltage is within the first voltage value range, the method may include controlling one or more switching components such that at least one heating element is bypassed, thereby reducing the total circuit resistance of the heating element through which current flows.

[0060] When the determined voltage is within the second voltage value range, the method may include controlling one or more switching components so that a total circuit resistance of the heating element through which the current flows is higher than a total circuit resistance of the heating element through which the current flows when the determined voltage is below the second voltage value range.

[0061] When the determined voltage is within a second voltage value range, the method may include controlling one or more switch components to cause current to flow in series through at least the third and fourth heating elements, thereby increasing a total circuit resistance of the heating elements through which the current flows.

[0062] The method may include controlling one or more switch components so that current flows through at least one heating element when the determined voltage is within a second voltage value range, and not flowing through the heating element when the determined voltage is outside the second voltage value range.

[0063] At least a plurality of heating elements may be connected in parallel with each other, each parallel-connected heating element being controllable by at least one switching element, and the method may include controlling the switching element in response to a signal to configure current to flow through:

[0064] a first set of heating elements; or

[0065] A second set of heating elements is different from the first set.

[0066] When the hair styling appliance comprises a first heater having a plurality of heating elements and a second heater having a plurality of heating elements, the method may further comprise controlling the first heater independently of the second heater.

[0067] When the hair styling appliance includes a first heater having a plurality of heating elements and a second heater having a plurality of heating elements, the method may include controlling one or more switch components of the hair styling appliance to reconfigure current flow through the plurality of heating elements such that power delivered to the first heater is different than power delivered to the second heater.

[0068] When the hair styling appliance comprises a first heater having a plurality of heating elements and a second heater having a plurality of heating elements, the method may comprise controlling a switch component of the hair styling appliance so that a total circuit resistance of the heating elements of the first heater through which current flows is different from a total circuit resistance of the heating elements of the second heater.

[0069] When the hair styling appliance comprises a first heater having a plurality of heating elements and a second heater having a plurality of heating elements, the method may comprise controlling the switch component to reconfigure one or both of the first and second heaters so that current flows through at least the first and second heating elements in parallel, thereby reducing the total circuit resistance of the first heating element through which the current flows.

[0070] When the hair styling appliance comprises a first heater having a plurality of heating elements and a second heater having a plurality of heating elements, the method may comprise controlling the switch component to reconfigure one or both of the first and second heaters so that current flows in series through at least the first and second heating elements, thereby increasing the total circuit resistance of the heating elements through which the current flows.

[0071] When the hair styling appliance comprises a first heater having a plurality of heating elements and a second heater having a plurality of heating elements, the method may comprise controlling the switch component to reconfigure the hair styling appliance so that current flows in parallel through at least the first and second heating elements of one of the first or second heaters and current flows in series through at least the first and second heating elements of the other of the first or second heaters.

[0072] Where appropriate, optional features of one aspect of the invention may be equally applied to other aspects of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to make the present invention more easily understood, the embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0074] Figure 1 is a schematic diagram of a longitudinal section of a hair straightener;

[0075] Figure 2 yes Figure 1 A plan view of a heater of a hair straightener;

[0076] Figures 3 to 5 A circuit including a heating element is shown;

[0077] Figures 6 to 8 Another circuit including a heating element is shown;

[0078] Figures 9 to 11 A further circuit is shown including a heating element;

[0079] Fig.12 A further circuit is shown including a heating element;

[0080] Fig.13 A further circuit is shown including a heating element;

[0081] Fig.14 A method of controlling a hair styling appliance is shown; and

[0082] Figures 15 to 20 A further circuit is shown comprising a heating element. DETAILED DESCRIPTION

[0083] The present application relates to a hair styling device, such as a hair dryer, a hair straightener, a curling iron or any other device for styling hair using heat (and optionally steam, ultrasonic mist and / or moving air).

[0084] The hair styling device comprises a plurality of heating elements for generating heat for styling hair when the device is in use. The device also comprises a sensor configured to determine the voltage of the electrical energy source or mains power supply when the device is turned on or plugged in, and output a signal indicative of the determined voltage and / or current output.

[0085] One or more switch components are connected to the heating elements. The switch components are controlled to reconfigure the current flowing through the plurality of heating elements at least in part depending on the signal.

[0086] The reconfiguration of current flow can be achieved in a variety of ways. For example, one or more of the heating elements can be switched into the heating circuit in series or in parallel with one or more other heating elements. Alternatively or additionally, one or more of the heating elements can be switched out of the heating circuit. One or more heating elements can be switched out by being bypassed or turned off. The net resistance of the circuit formed by the heating elements can be changed as a result of the current reconfiguration.

[0087] The hair styling appliance may be configured so that it can automatically operate at different mains supply voltages without user intervention. For example, two common mains voltage standards are the nominal 120 Vac standard (e.g., used in North America) and the nominal 230 Vac standard (e.g., used in Europe). The hair styling appliance may be configured to operate properly at both the 120 Vac standard and the 230 Vac standard. The hair styling appliance may also be configured so that the electrical connections of the heating element can be automatically reconfigured and can operate reliably as the voltage of the electrical source fluctuates or decreases.

[0088] The hair styling appliance may operate based on identifying at least two different ranges of voltage values ​​and reconfiguring the current flow based on the range in which the voltage is determined to lie.

[0089] refer to Figure 1 , a hair styling device in the form of a hair straightener 100 is shown. The hair straightener 100 comprises a handle 172. A first arm 174 and a second arm 176 are connected to the handle 172 at a hinge 178 so that the arms can be pivoted away from each other.

[0090] The first arm 174 includes a first hair contact plate 122 and the second arm 176 includes a second hair contact plate 124. The first plate 122 and the second plate 124 are formed of a thermally conductive material and may include a low friction coating.

[0091] A spring (not shown) biases the arms away from each other so that a user can position a strand of hair (not shown) between the first and second plates 122 , 124 and then squeeze the first and second arms 174 , 176 together to capture the strand of hair between the first and second plates 122 , 124 .

[0092] The hair straightener 100 includes a first heater 102 and a second heater 104. Figure 2As shown, the first heater 102 includes a plurality of heating elements in the form of a first heating element 106 and a second heating element 108. The first heating element 106 and the second heating element 108 are in the form of a resistive trace formed on a substrate 110. The substrate 110 may be in the form of a heat-resistant ceramic plate, for example. The first heating element 106 and the second heating element 108 are castellated in a plane and interlaced with each other. Other shapes, such as a sine curve, may also be used.

[0093] The second heater 104 includes heating elements arranged similarly to the first and second heating elements 106 and 108 and will not be described in detail.

[0094] Any other suitable arrangement or configuration of heating elements may be used. For example, the heating elements may be stacked with an electrically insulating layer (such as a ceramic substrate) disposed between them. Each heating element may consist of more than one trace, connected in any suitable parallel and / or series combination.

[0095] The first heater 102 and the second heater 104 are in close proximity to the hair contact plates 122 and 124 so that when the first heater 102 and the second heater 104 are heated, they heat the corresponding hair contact plates 122 and 124. The staggering of the first heating element 106 and the second heating element 108 allows heat to be transferred to a very large width of the hair contact plates 122 and 124 regardless of which of the first heating element 106 and / or the second heating element 108 is heated. Once the hair contact plates 122 and 124 are sufficiently hot, the hair straightener 100 can be used to straighten and style the hair, as will be appreciated by those skilled in the art.

[0096] The hair straightener 100 also includes a sensor in the form of a voltage sensor 112 connected to sense the voltage of an onboard electrical energy source or input mains power. Mains power is supplied to the hair straightener 100 by means of a power cord 114 terminating in a mains plug 116 configured to be plugged into a mains voltage socket. The voltage sensor 112 is configured to output a signal in the form of a voltage signal to a controller 118 indicative of the determined voltage.

[0097] The hair straightener 100 includes a heater driver 120 that includes a plurality of switching components. The switching components in the hair straightener 100 are in the form of TRIACs that are connected to the first and second heating elements 106 and 108, as shown in FIG. Figures 3 to 5 Alternatively, for example, if the heating element is powered by a DC power supply, the switch component in the hair straightener 100 may be in the form of an IGBT, a field effect transistor, or the like.

[0098] The voltage sensor 112, controller 118, and heater driver 120 are shown as being located within the handle 172. However, those skilled in the art will recognize that in different embodiments, these components may be located elsewhere. For example, one or more of these components may be located in a separate housing (not shown) that is connected to the hair straightener 100 via a flexible cable that carries power and / or control signals to the hair straightener 100. In other embodiments that include a fan (not shown) or other motor-driven components, the motor driver (not shown) may similarly be disposed within such a separate housing.

[0099] The hair straightener 100 is configured such that a switching component, such as a TRIAC or an IGBT, is controlled to reconfigure the current flowing through the first and second heating elements 106 and 108 at least partially dependent on the voltage signal.

[0100] Figures 3 to 5 A schematic diagram is shown of a first heating element 106, a second heating element 108 and switching means in the form of first TRIAC 126, second TRIAC 128 and third TRIAC 130. The arrangement and operation of the heating elements in the second heater 104 are similar and therefore will not be described in detail.

[0101] The first heating element 106 and the first TRIAC 126 are connected in series between the live terminal 132 and the neutral terminal 134. The second TRIAC 128 and the second heating element 108 are connected in series between the live terminal 132 and the neutral terminal 134. The third TRIAC 130 is connected between the connection point between the first heating element 106 and the first TRIAC 126 and the connection point between the second TRIAC 128 and the second heating element 108.

[0102] Figures 15 to 20 A schematic diagram of the first heating element 106, the second heating element 108 and switch means in the form of first switch 1126, second switch 1128 and third switch 1130 is shown. The arrangement and operation of the heating elements in the second heater 104 are similar and therefore will not be described in detail.

[0103] In such Figures 15 to 20In the alternative arrangement shown, the second switch 1128 and the third switch 1130 are connected in series between the first terminal 1132 and the second terminal 1134. The first heating element 106 and the first switch 1126 are connected in series between the first terminal 1132 and the second terminal 1134. The second heating element 108 is connected between the connection point between the second switch 1128 and the third switch 1130 and the connection point between the first heating element 106 and the first switch 1126. Therefore, the first heating element 106 and the second heating element 108 share an electrical connection without any connection point or switch component therebetween. All operating states described below with respect to the TRIACs 126, 128, 130 and the terminals 132, 134 also apply to the switches 1126, 1128, 1130 and the terminals 1132, 1134, respectively.

[0104] Figures 15 to 20 The arrangement shown can be particularly advantageous because by configuring the first heating element 106 and the second heating element 108 with a common electrical connection, this reduces the number of connection points and cables required, thereby reducing overall power loss and component and assembly costs. With the reduction in power loss, the control signal can cause the switch component to operate in the on state for a longer period of time and with a relatively lower peak current compared to an equivalent circuit design in which the first heating element 106 and the second heating element 108 do not share a common electrical connection. Therefore, the circuit design can be further simplified without affecting performance, and fewer connectors can be used, more effectively utilizing available circuit space, and reducing manufacturing and assembly costs.

[0105] Apart from Figures 15 to 17 The arrangement shown in FIG. is similar in operation to Figures 3 to 5 In addition to the equivalent arrangement shown in Figures 18 to 20 Other arrangements are shown in which provide alternative operating states.

[0106] The control terminals of the first TRIAC 126, the second TRIAC 128, and the third TRIAC 130 are connected to the controller 118. As described in more detail below, the controller 118 provides control signals to the first TRIAC 126, the second TRIAC 128, and the third TRIAC 130 to reconfigure the current flowing through the TRIACs and, therefore, the current flowing through the first heating element 106 and the second heating element 108.

[0107] The mains plug 116 may be plugged into a mains voltage socket (not shown). When the hair straightener 100 is turned on or in standby mode, the voltage sensor 112 determines the voltage of the mains power source and outputs a corresponding voltage signal to the controller 118 .

[0108] The voltage signal may take any suitable form. For example, the voltage signal may be a variable voltage that may be converted to a numerical value by an analog to digital converter, which may form part of the controller 118, or may be a separate circuit. Alternatively, the voltage signal may be a numerical value that may be read directly by the controller 118.

[0109] In yet other embodiments, the voltage signal may be used directly without conversion to a numerical value, for example by taking the form of a variable voltage that directly controls one or more circuits that in turn control the first TRIAC 126 , the second TRIAC 128 , and the third TRIAC 130 .

[0110] The controller 118 may be configured to determine whether the determined voltage is within a first voltage value range. This may include, for example, determining that the determined voltage is between a first lower threshold and a first upper threshold. Alternatively, this may include determining that the determined voltage is below a threshold.

[0111] In at least some embodiments, it may be advantageous to clearly distinguish between an upper voltage range and a lower voltage range to ensure correct configuration of the heating element and the switch component. For example, the hair styling appliance may be configured so that it does not operate if the detected mains supply voltage or electrical energy source voltage is between a first upper threshold and a second lower threshold.

[0112] In an alternative embodiment, only a single threshold is used. The threshold may be, for example, between about 140 Vac and 176 Vac. For example, such a single threshold may be around 150 Vac.

[0113] When the hair straightener 100 is configured for use in a nominal 120 Vac region, the first lower threshold may be, for example, 85 Vac, and the first upper threshold may be, for example, 140 Vac.

[0114] When the voltage is determined to be between the first and second lower thresholds, it can be concluded that the hair straightener 100 has been plugged into a nominal 120 Vac mains voltage socket. Therefore, the first TRIAC 126, the second TRIAC 128 and the third TRIAC 130 are controlled so that the total circuit resistance of the heating element through which the current flows is lower than the total circuit resistance of the heating element through which the current flows when the determined voltage exceeds the first voltage value range.

[0115] exist Figure 3 In the embodiment, the controller 118 controls the first TRIAC 126, the second TRIAC 128 and the third TRIAC 130 so that they do not conduct any current. For example, such a state may exist when the hair straightener 100 is in standby mode, in which the first plate 122 is not heated.

[0116] Similarly, in Fig.15 In the embodiment, the controller 118 controls the first switch 1126, the second switch 1128 and the third switch 1130 so that they do not conduct any current. For example, when the hair straightener 100 is placed in standby mode, such a state may exist in which the first plate 122 is not heated.

[0117] refer to Figure 4 When the voltage is between the first lower threshold and the second lower threshold, controlling the TRIACs 126 , 128 , and 130 involves controlling the first TRIAC 126 and the second TRIAC 128 so that they conduct current while maintaining the third TRIAC 130 in an “off” state.

[0118] Similarly, refer to Fig.16 When the voltage is between the first and second lower thresholds, controlling switches 1126, 1128, and 1130 involves controlling the first switch 1126 and the second switch 1128 so that they conduct current while maintaining the third switch 1130 in an "off" state.

[0119] If the first TRIAC 126 and the second TRIAC 128 are controlled (or Fig.16 In the embodiment, the first switch 1126 and the second switch 1128 are turned on, and the final effect is that the first heating element 106 is connected in parallel with the second heating element 108. Therefore, the net resistance of the first heater 102 is given by the calculation formula of the parallel resistance:

[0120] 1 / R T = 1 / R 106 + 1 / R 108

[0121] Among them, R T is the net resistance, R 126 is the resistance of the first heating element 106, R 108 is the resistance of the second heating element 108 .

[0122] Optionally, either or both of the first and second TRIACs 126 and 128 may be controlled by the controller 118 such that they modulate the current flowing through them. For example, the controller 118 may control either or both of the first and second TRIACs 126 and 128 according to, for example, a burst / multi-cycle triggering control scheme, a phase angle control scheme, a combination thereof, or any other suitable control scheme for controlling a TRIAC. TRIAC control schemes are well known to those skilled in the art and are therefore not described in detail.

[0123] Optionally, modulation of either or both of the first and second TRIACs 126 and 128 may be used to control the average amount of current flowing through either or both of the first and second heating elements 106 and 108 in order to achieve a desired overall heating performance. For example, in some embodiments, it may be desirable for the first TRIAC 126 to operate at a lower duty cycle than the second TRIAC 128.

[0124] Alternatively or additionally, a suitable modulation scheme may be employed for either or both of the first and second TRIACs 126 and 128 to optimize electromagnetic compatibility (EMC), including flicker, harmonics, and other conducted emissions.

[0125] The controller 118 may additionally or alternatively be configured to determine whether the determined voltage is within a second voltage value range. This may include, for example, determining that the determined voltage is between a second lower threshold and a second upper threshold. Alternatively, this may include determining that the determined voltage is above a threshold. In this case, the threshold may be, for example, a first upper threshold.

[0126] When the hair straightener 100 is configured for use in a nominal 230 Vac region, the second lower threshold may be, for example, 176 Vac, and the second upper threshold may be, for example, 264 Vac.

[0127] When it is determined that the voltage is between the first and second upper thresholds, it can be concluded that the hair straightener 100 has been plugged into a nominal 230 Vac mains voltage socket. Therefore, the first TRIAC 126, the second TRIAC 128 and the third TRIAC 130 are controlled so that the total circuit resistance of the heating element through which the current flows is higher than the total circuit resistance of the heating element through which the current flows when the determined voltage is below the first voltage value range.

[0128] refer to Figure 5 When the voltage is between the first and second upper thresholds, controlling the TRIACs 126 , 128 , and 130 involves controlling the third TRIAC 130 so that it conducts current while maintaining the first TRIAC 126 and the second TRIAC 128 in an “off” state.

[0129] Similarly, refer to Fig.17 When the voltage is between the first and second upper thresholds, controlling switches 1126, 1128, and 1130 involves controlling third switch 130 so that it conducts current while maintaining first switch 1126 and second switch 1128 in an "off" state.

[0130] If the third TRIAC130 (or Fig.17The net resistance of the first heater 102 is thus given by the series resistance formula:

[0131] R T = R 106 + R 108

[0132] Where R T is the net resistance, R 106 is the resistance of the first heating element 106, R 108 is the resistance of the second heating element 108 .

[0133] Optionally, the third TRIAC 130 can be controlled by the controller 118 so that it modulates the current flowing through it. For example, the controller 118 can control the third TRIAC according to, for example, a burst trigger / multi-cycle control scheme, a phase angle control scheme, a combination thereof, or any other suitable control scheme for controlling a TRIAC.

[0134] Go to Figures 6 to 8 , an alternative circuit is shown which comprises a switching component in the form of a TRIAC connected to a heating element. Figures 6 to 8 The circuit shown consists of Figures 3 to 5 Like reference symbols are used to denote like components with corresponding numbers in the circuits shown in FIG.

[0135] In addition to the first and second heating elements 106 and 108 and the first, second and third TRIACs 126, 128 and 130, Figures 6 to 8 The illustrated circuit also includes a third heating element 138 and a fourth TRIAC 140 connected in series between the live terminal 132 and the neutral terminal 134 .

[0136] Figure 6 and Figure 3 Correspondingly, the controller 118 maintains all TRIACs in the “off” state.

[0137] Figure 7 and Figure 4 Correspondingly, the determined voltage indicates that the hair straightener 100 has been plugged into a nominal 120Vac mains voltage socket. The controller 118 controls the first and second TRIACs 126 and 128 so that they conduct current, and keeps the third TRIAC 130 in the "off" state, so that the first heating element 106 is actually connected in parallel with the second heating element 108. At the same time, the controller 118 controls the fourth TRIAC 140 so that it conducts current, so that the third heating element 138 is also actually connected in parallel with the first heating element 106 and the second heating element 108.

[0138] When the first, second and fourth TRIACs 126, 128 and 140 are turned on and the third TRIAC 130 is turned off, Figure 6 The net resistance of the circuit shown is given by the formula for parallel resistance:

[0139] 1 / R T = 1 / R 106 + 1 / R 108 + 1 / R 138

[0140] Among them, R T is the net resistance, R 106 is the resistance of the first heating element 106, R 108 is the resistance of the second heating element 108, R 138 is the resistance of the third heating element 138 .

[0141] Figure 8 and Figure 5 Correspondingly, the determined voltage indicates that the hair straightener 100 has been plugged into a nominal 230Vac mains voltage socket. The controller 118 controls the third TRIAC 130 so that it conducts current, and keeps the first and second TRIACs 126 and 128 in the "off" state, so that the first heating element 106 is actually connected in series with the second heating element 108. At the same time, the controller 118 controls the fourth TRIAC 140 so that it conducts current, so that the third heating element 138 is actually also connected in parallel with the resistance of the first heating element 106 and in series with the second heating element 108.

[0142] When the first, second and fourth TRIACs 126, 128 and 140 are turned on and the third TRIAC 130 is turned off, Figure 6 The net resistance of the circuit shown is given by the formula for parallel resistance:

[0143] 1 / R T = 1 / (R 106 + R 108 ) + 1 / R 138

[0144] The fourth TRIAC 140 may be controlled by the controller 118 such that it modulates the current flowing therethrough. For example, the controller 118 may control the fourth TRIAC 140 according to, for example, a burst firing / multi-cycle control scheme, a phase angle control scheme, a combination thereof, or any other suitable control scheme for controlling a TRIAC.

[0145] Optionally, any or all of the first, second, third, and fourth TRIACs 126, 128, 130, and 140 may be modulated to control the average amount of current flowing through any or all of the first, second, and third heating elements 106, 108, and 138 to achieve a desired overall heating performance. For example, in some embodiments, it may be desirable to operate one or more TRIACs at a lower duty cycle than one or more other TRIACs.

[0146] Alternatively, or in addition, modulation of any or all of the TRIACs may be used to optimize electromagnetic compatibility (EMC), as described above.

[0147] Alternatively or additionally, the controller 118 may turn the fourth TRIAC 140 “off”, reconfiguring Figures 6 to 8 The controller 118 may turn the fourth TRIAC 140 “off” depending at least in part on the determined voltage.

[0148] Go to Figures 9 to 11 , an alternative circuit is shown, comprising a switching component in the form of a TRIAC connected to the heating element. Figures 6 to 8 The circuit shown includes multiple Figures 3 to 5 Corresponding components of the circuits shown are shown, and the same reference symbols are used to indicate similar components.

[0149] Figures 9 to 11 The circuit includes a first heating element 142 , a second heating element 144 , a third heating element 146 , a fourth heating element 148 , a first TRIAC 150 , a second TRIAC 152 , a third TRIAC 154 , and a fourth TRIAC 156 .

[0150] A first heating element 142 and a first TRIAC 150 are connected in series between the live terminal 132 and the neutral terminal 134. A second heating element 144 and a second TRIAC 152 are connected in series between the live terminal 132 and the neutral terminal 134. A third heating element 146 and a third TRIAC 154 are connected in series between the live terminal 132 and the neutral terminal 134, and a fourth heating element 148 and a fourth TRIAC 156 are connected in series between the live terminal 132 and the neutral terminal 134. From an electrical perspective, each connected heating element and TRIAC pair is in parallel with all other heating element and TRIAC pairs.

[0151] The control terminals of the first TRIAC 150, the second TRIAC 152, the third TRIAC 154, and the fourth TRIAC 156 are connected to the controller 118. As described in more detail below, the controller 118 provides control signals to the TRIACs to reconfigure the current flowing through them, thereby reconfiguring the current flowing through the first heating element 142, the second heating element 144, the third heating element 146, and the fourth heating element 148, at least in part depending on the determined voltage.

[0152] The first and second heating elements 142 and 144 form a first group, and the third and fourth heating elements 146 and 148 form a second group. In this context, a "group" means a group of TRIACs that are controlled together by the controller 118 at least in part dependent on the determined voltage. While this may mean that all TRIACs in each group are controlled identically, it may also be the case that the individual TRIACs within a group are modulated differently depending at least in part on, for example, the mode or setting of the hair straightener 100 selected by the user and / or the determined voltage.

[0153] When the voltage is determined to be between the first and second lower thresholds, it can be concluded that the hair straightener 100 has been plugged into a nominal 120 Vac mains voltage socket. Therefore, the first, second, third and fourth TRIACs 150, 152, 154 and 156 are controlled so that the total circuit resistance of the heating element through which the current flows is lower than the total circuit resistance of the heating element through which the current flows when the determined voltage exceeds the first voltage value range.

[0154] exist Fig. 9 In the embodiment, the controller 118 controls all TRIACs so that they do not conduct any current. For example, when the hair straightener 100 is placed in standby mode, such a state may exist in which the first plate 122 is not heated.

[0155] exist Fig.10 In FIG. 1 , when the voltage is between the first and second lower thresholds, controlling TRIACs 150, 152, 154, and 156 involves turning on all TRIACs. The net effect is that all heating elements are connected in parallel with each other. Therefore, the net resistance of the first heater 102 is given by the parallel resistance calculation formula:

[0156] 1 / R T = 1 / R 142 + 1 / R 144 + 1 / R 146 + 1 / R 148

[0157] Where R T is the net resistance, R 142is the resistance of the first heating element 142, R 144 is the resistance of the second heating element 144, R 146 is the resistance of the third heating element 146, and R 148 is the resistance of the fourth heating element 148 .

[0158] Optionally, any or all of the TRIACs 150, 152, 154, and 156 may be controlled by the controller 118 such that they modulate the current flowing through them. For example, the controller 118 may control any or all of the TRIACs according to, for example, a burst firing / multi-cycle control scheme, a phase angle control scheme, a combination thereof, or any other suitable control scheme for controlling TRIACs.

[0159] Alternatively, modulation of any or all TRIACs may be used to control the average amount of current flowing through any or all TRIACs as a whole to achieve the desired overall heating. For example, in some embodiments, it may be desirable to have one or more TRIACs operate at a lower duty cycle than one or more other TRIACs.

[0160] Alternatively or additionally, as described above, modulation of any or all of the TRIACs 150 , 152 , 154 , and 156 may be used to optimize electromagnetic compatibility (EMC).

[0161] When it is determined that the voltage is between the first and second upper thresholds, it can be concluded that the hair straightener 100 has been plugged into a nominal 230 Vac mains voltage socket. Therefore, the TRIACs 150, 152, 154 and 156 are controlled so that the total circuit resistance of the heating elements through which the current flows is higher than the total circuit resistance of the heating elements through which the current flows when the determined voltage is below the first voltage value range.

[0162] refer to Fig.11 When the voltage is between the first and second upper thresholds, controlling the TRIACs 150 , 152 , 154 , and 156 involves controlling the first and second TRIACs 150 , 152 so that they conduct current while maintaining the third and fourth TRIACs 154 , 156 in an “off” state.

[0163] If the first and second TRIACs 150, 152 are controlled so that they are conducting, the net effect is that the first heating element 142 is connected in parallel with the second heating element 144. Therefore, the net resistance of the first heater 102 is given by the calculation formula for parallel resistance:

[0164] 1 / R T = 1 / R 142 + 1 / R 144

[0165] Where RT is the net resistance, R 142 is the resistance of the first heating element 142, R 144 is the resistance of the second heating element 144 .

[0166] Optionally, the first TRIAC 150 and / or the second TRIAC 152 may be controlled by the controller 118 such that they modulate the current flowing through them. For example, the controller 118 may control the first TRIAC 150 and / or the second TRIAC 152 according to, for example, a burst trigger / multi-cycle control scheme, a phase angle control scheme, a combination thereof, or any other suitable control scheme for controlling a TRIAC.

[0167] although Figures 9 to 11 The groups in the first group and the second group do not overlap, but it will be appreciated by those skilled in the art that any number of heating elements may be present in the first group and the second group. All that is desired is that one of the groups includes at least one heating element that is not present in the other group.

[0168] In other embodiments, one or more switching components may be controlled, at least in part, in dependence on the determined voltage, such that current does not flow through at least one heating element. Fig.12 A schematic diagram of a first heating element 158 ​​connected in series with a first TRIAC 160 and a second heating element 162 connected in series with a second TRIAC 164 is shown. The first heating element 158 ​​and the first TRIAC 160 are connected in series between the live terminal 132 and the neutral terminal 134. The second heating element 162 and the second TRIAC 164 are connected between the connection point between the first heating element 158 ​​and the first TRIAC 160 and the neutral terminal 134.

[0169] When the determined voltage is within the first voltage value range, one or more switch components are controlled so that at least one heating element is bypassed, thereby reducing the total circuit resistance of the heating element through which the current flows. Fig.12 In the embodiment of the present invention, this means that the controller 118 controls the first TRIAC 160 to turn it on and maintains the second TRIAC 164 in the "off" state. In this way, the second heating element 162 is bypassed, thereby reducing the total circuit resistance.

[0170] When the determined voltage is within the second voltage value range, the controller 118 maintains the first TRIAC 160 in the "off" state and controls the second TRIAC 164 to turn it on. In this way, the second heating element 162 is no longer bypassed. The current must now flow in series through both the first heating element 158 ​​and the second heating element 162, which results in a higher total circuit resistance than when the determined voltage is within the first voltage value range.

[0171] Those skilled in the art will appreciate that by arranging for different series and / or parallel connected heating elements to be selectively bypassed, depending at least in part on the determined voltage, different circuit resistances may be achieved.

[0172] Optionally, in any embodiment, any one or more individual TRIACs may be controlled at least in part dependent upon a user-selected mode or setting of the hair straightener 100. The user may select such a mode or setting via a user interface (not shown) comprising one or more switches, dials, sliders, buttons, touch surfaces, or other input elements provided as part of the user interface. The user interface may also provide feedback via one or more screens, lights, sounds, etc.

[0173] For example, the hair straightener 100 may have a "low" heat setting and a "high" heat setting. In addition to controlling the TRIAC in dependence on the current mains supply voltage, the controller 118 may also control the TRIAC to increase or decrease the total power output of the heating element depending on the currently selected heat setting.

[0174] Other possible modes and arrangements will be apparent to those skilled in the art.

[0175] In either switch component combination, if there is a potential series path that does not pass through at least one heating element, it may be desirable to include a safety resistor to mitigate the effects of unexpected overcurrent events. Such events may be caused by, for example, hardware or software errors and / or mains surge conditions.

[0176] Fig.13 is a schematic circuit showing one example of such a safety resistor. Fig.13 The circuit and Figures 3 to 5 The circuits shown correspond and like reference numerals are used to denote similar components except that a further resistor 166 is included in series with the first, second and third TRIACs 126 , 128 and 130 , with no other resistance in this path between the live rail 132 and the neutral rail 134 .

[0177] When the third TRIAC 130 is off (eg, in nominal 120 Vac mode), the other resistor 166 is bypassed and no heat is dissipated.

[0178] When the third TRIAC 130 is on (e.g., in nominal 230Vac mode), current will flow through another resistor 166. Although another resistor 166 is placed near the third TRIAC 130, it can alternatively be placed anywhere in the series connection of the first, second and third TRIACs 126, 128 and 130.

[0179] The value of the other resistor 166 can be selected so that it can pass the required current without overheating. In this case, the other resistor 166 can be designed around a relatively low operating temperature component.

[0180] Alternatively, the further resistor 166 may include one or more heating elements that form part of a series circuit through the first, second and third TRIACs 126, 128 and 130. The heat generated by the further resistor 166 (or resistors) may be considered when designing the thermal performance of the overall heating circuit.

[0181] For example, the further resistor 166 may form part of the same physical resistive heating element as the first heating element 106. In such an arrangement, the first TRIAC 126 is electrically connected at a suitable point along the physical resistive heating element from which the first heating element 106 and the further resistor 166 are formed. This effectively divides the physical resistive heating element into the first heating element 106 and the further resistor 166. The connection is positioned so as to divide the total resistance of the physical resistive heating element between the first heating element 106 and the further resistor 166.

[0182] Another resistor 166 may alternatively be positioned at any other point in the electrical path through the TRIAC from the positive or first rail to the neutral or second rail.

[0183] The resistance of the other resistor 166 is selected to limit the amount of current flowing through all TRIACs when they are turned on simultaneously. Limiting the current can reduce the possibility of damage to the TRIACs due to overcurrent and can also (or) provide operating time for the safety circuit.

[0184] Although the use of a TRIAC has been described, those skilled in the art will recognize that other switching components may be used, either alone or in combination with other switching / modulating elements such as the TRIAC described previously.

[0185] Examples of such switching components include: insulated gate bipolar transistors (IGBTs), field effect transistors, mechanical relays, and any form of semiconductor switch or modulation device. An appropriate type (or types) of switching components may be used, depending on the manner in which power is delivered to the heating element. For example, if the heating element is supplied with DC current from a mains powered DC power source or an electrical energy source including a secondary battery, then a TRIAC will not be applicable and an IGBT, field effect transistor, etc. may be used instead.

[0186] Optionally, one or more hardware interlocks may be provided to provide an additional degree of protection against accidental switching of the switching components due to hardware failure or software error. For example, one or more hardware or semiconductor relays may be provided that correspond to one or more switching components. The hardware or semiconductor relays may be controlled so that power is only provided to those switching components that will be switched by the switch given the determined voltage. Alternatively or additionally, the gate drive signals of the TRIACs may be interlocked to prevent the TRIACs from firing simultaneously, which would result in a short circuit path between the positive rail and the neutral rail.

[0187] Although the heating elements have been described as resistive traces on a substrate, it will be appreciated that any suitable form of heating element(s) may be used, depending on the specific application requirements. For example, the heating element(s) may include resistive wire or ribbon, wrapped or otherwise mounted to one or more substrates, formers, or supports. They may be configured to directly heat components (e.g., first and second plates 122 and 124) or air (e.g., as required for a hair dryer). Alternatively, they may be configured to provide indirect heat (e.g., a heating element may heat a diffuser, which in turn heats the air as it passes through).

[0188] Although the sensor is described as a voltage sensor, a person skilled in the art will appreciate that the term "sensor" is used broadly. In the context of the present application, a "sensor" includes any combination of circuits and / or components that output one or more signals indicative of the voltage of the mains power supply to which the hair styling appliance is connected.

[0189] The use of signals that "indicate" voltage is also widespread, both directly and indirectly. "Direct indication" includes arrangements where, for example, a sensor outputs an analog or digital signal that indicates a particular mains voltage or voltage range. "Indirect indication" means that the output of a sensor depends on the mains voltage, but does not directly indicate it. For example, a sensor may measure the current at a particular point, which varies depending on the mains voltage. A sensor may measure the temperature of a particular component or components, where the temperature varies depending on the mains voltage. There is no need to explicitly convert the current or temperature signal into a voltage before using it.

[0190] Any number of additional heating elements may also be provided to meet the requirements of a particular implementation. Such additional heating elements may be connected in series, in parallel, or in any combination with any other heating element or circuit containing multiple heating elements.

[0191] When using the formula for parallel resistance here, it is assumed that all relevant TRIACs are turned on simultaneously. When fewer TRIACs are turned on, the net instantaneous resistance will change accordingly and can be calculated in a known manner by those skilled in the art.

[0192] Go to Fig.14 , which shows a flow chart of a method 168 for controlling a hair styling appliance. The hair styling appliance includes: a plurality of heating elements; a sensor for determining a voltage and / or current output of a mains power source and outputting a signal (such as a voltage and / or current signal) indicative of the determined voltage and / or current output; and one or more switch components connected to the heating elements. For example, the hair styling appliance can take the form of any hair styling appliance and alternatives described herein.

[0193] The method 168 comprises determining 170 a mains supply voltage, and controlling 172 one or more switching components to reconfigure current flow through the plurality of heating elements depending at least in part on the determined voltage.

[0194] When the determined voltage is within the first voltage value range, control of one or more switching components can make the total circuit resistance of the heating element through which the current flows lower than the total circuit resistance of the heating element through which the current flows when the determined voltage exceeds the first voltage value range.

[0195] For example, when the determined voltage is within a first voltage value range, the method may involve controlling one or more switching components such that current flows in parallel through at least the first and second heating elements, thereby reducing a total circuit resistance of the heating elements through which the current flows.

[0196] Additionally, when the determined voltage is within a first voltage value range, the method may involve controlling one or more switching components so that current does not flow through at least one heating element other than the first and second heating elements, thereby reducing a total circuit resistance of the heating elements through which current flows.

[0197] When the determined voltage is within a first voltage value range, one or more switch components may be controlled such that at least one heating element is bypassed, thereby reducing a total circuit resistance of the heating element through which current flows.

[0198] When the determined voltage is within a second voltage value range, the method may involve controlling one or more switching components so that a total circuit resistance of the heating element through which the current flows is higher than a total circuit resistance of the heating element through which the current flows when the determined voltage is below the second voltage value range.

[0199] For example, when the determined voltage is within a second voltage value range, the method may involve controlling one or more switching components such that current flows in series through at least the third and fourth heating elements, thereby increasing a total circuit resistance of the heating elements through which the current flows.

[0200] Additionally, when the determined voltage is within a second voltage value range, the method may involve controlling one or more switching components so that current does not flow through at least one heating element other than the first and second heating elements, thereby reducing a total circuit resistance of the heating elements through which current flows.

[0201] At least a plurality of heating elements may be connected in parallel with each other, each parallel-connected heating element being controllable by at least one switch component. In this case, the method may involve controlling the switch component in response to the signal to configure the current flowing through the following groups:

[0202] a first group of heating elements in the heating elements; or

[0203] A second set of heating elements is different from the first set of heating elements.

[0204] The hair styling appliance may include a controller connected to control the one or more switch members. In this case, the method may include receiving a signal from the sensor at the controller.

[0205] Although a hair straightener has been described, those skilled in the art will appreciate that the present invention may be applied to other forms of hair styling appliances, hair dryers, curling irons, different forms and types of hair straighteners than those described in detail above, or any other such device for styling hair using heat (and optionally moving air).

[0206] Although the invention has been described with reference to various embodiments, it will be appreciated by those skilled in the art that the invention can be embodied in many other forms and is limited only by the scope of the claims.

Claims

1. A hair styling device comprising: multiple heating elements; a sensor for determining a voltage and / or current output of a source of electrical energy and outputting a signal indicative of the determined voltage and / or current output; as well as one or more switch components connected to the heating element; Wherein the hair styling appliance is configured such that the one or more switch components are controlled to reconfigure the current flowing through the plurality of heating elements at least in part dependent on the signal.

2. A hair styling device according to claim 1, wherein: When the determined voltage is within a first voltage value range, the one or more switching components are controlled so that a total circuit resistance of the heating element through which current flows is lower than a total circuit resistance of the heating element through which current flows when the determined voltage exceeds the first voltage value range.

3. A hair styling device according to claim 2, wherein: When the determined voltage is within the first voltage value range, the one or more switch components are controlled so that the current flows in parallel through at least the first heating element and the second heating element of the heating elements, thereby reducing the total circuit resistance of the heating elements through which the current flows.

4. A hair styling device according to claim 2 or 3, wherein: When the determined voltage is within the first voltage value range, the one or more switching components are controlled so that the current does not flow through at least one of the heating elements other than the first heating element and the second heating element, thereby reducing the total circuit resistance of the heating elements through which the current flows.

5. A hair styling device according to any one of claims 2 to 4, wherein: When the determined voltage is within the first voltage value range, the one or more switching components are controlled such that at least one of the heating elements is bypassed, thereby reducing the total circuit resistance of the heating element through which current flows.

6. A hair styling appliance according to any one of the preceding claims, wherein: When the determined voltage is within a second voltage value range, the one or more switching components are controlled so that a total circuit resistance of the heating element through which current flows is higher than a total circuit resistance of the heating element through which current flows when the determined voltage is below the second voltage value range.

7. A hair styling device according to claim 6, wherein: When the determined voltage is within the second voltage value range, the one or more switch components are controlled so that the current flows in series through at least the third and fourth of the heating elements, thereby increasing the total circuit resistance of the heating elements through which the current flows.

8. A hair styling device according to claim 6 or 7, wherein: When the determined voltage is within the second voltage value range, the one or more switch components are controlled so that the current flows through at least one of the heating elements, and when the determined voltage is outside the second voltage value range, the current does not flow through the at least one of the heating elements.

9. A hair styling device according to any one of claims 6 to 8, wherein When the determined voltage is within the second voltage value range, the one or more switching components are controlled so that current flows through at least one of the heating elements, thereby reducing the total circuit resistance of the heating element through which the current flows. When the determined voltage is lower than the second voltage value range, current does not flow through the at least one heating element.

10. A hair styling appliance according to any preceding claim, wherein At least a plurality of heating elements are connected in parallel with each other, each of the parallel-connected heating elements being controllable by at least one of the switch components, the hair styling appliance being configured such that the one or more switch components are controlled in response to the signal, thereby configuring current to flow through: a first set of heating elements; or A second set of heating elements is provided that is different from the first set.

11. A hair styling appliance according to any preceding claim, wherein at least two of the plurality of heating elements are connected to the switch member via a common electrical connection.

12. A hair styling appliance according to any preceding claim, wherein the hair styling appliance comprises a first heater and a second heater, each heater comprising a respective plurality of heating elements, and the hair styling appliance is configured such that the first heater is controllable independently of the second heater.

13. A hair styling appliance according to any preceding claim, wherein the hair styling appliance comprises a first heater and a second heater, each heater comprising a respective plurality of heating elements, and the hair styling appliance is configurable such that one or more switch components are controlled to reconfigure the current flowing through the plurality of heating elements such that the power delivered to the first heater is different to the power delivered to the second heater.

14. A hair styling appliance according to any preceding claim, wherein the hair styling appliance comprises a first heater and a second heater, each heater comprising a respective plurality of heating elements, and the hair styling appliance is reconfigurable such that a total circuit resistance through which current flows of the heating elements of the first heater is different from a total circuit resistance of the heating elements of the second heater.

15. A hair styling appliance according to any one of the preceding claims, wherein the hair styling appliance comprises a first heater and a second heater, each heater comprising a respective plurality of heating elements, and the hair styling appliance is configurable such that one or more switch components are controlled such that the current flows in parallel through at least the first heating element and the second heating element of one of the first or second heaters, while the current flows in series through at least the first heating element and the second heating element of the other of the first or second heaters.

16. A method of controlling a hair styling appliance, the hair styling appliance comprising: multiple heating elements; a sensor for determining a voltage and / or current output of the source of electrical energy and outputting a signal indicative of the determined voltage and / or current output; one or more switch components connected to the heating element; The method includes controlling the one or more switching components to reconfigure current flow through the plurality of heating elements dependent at least in part on the signal.

17. The method according to claim 16, comprising: When the determined voltage is within a first voltage value range, the one or more switching components are controlled so that a total circuit resistance of the heating element through which current flows is lower than a total circuit resistance of the heating element through which current flows when the determined voltage exceeds the first voltage value range.

18. The method according to claim 17, comprising: When the determined voltage is within the first voltage value range, the one or more switch components are controlled so that the current flows in parallel through at least the first heating element and the second heating element of the heating elements, thereby reducing the total circuit resistance of the heating elements through which the current flows.

19. The method according to claim 17 or 18, comprising: When the determined voltage is within the first voltage value range, the one or more switch components are controlled so that the current does not flow through at least one of the heating elements other than the first heating element and the second heating element, thereby reducing the total circuit resistance of the heating elements through which the current flows.

20. A method according to any one of claims 17 to 19, comprising: When the determined voltage is within the first voltage value range, the one or more switch components are controlled such that at least one of the heating elements is bypassed, thereby reducing the total circuit resistance of the heating element through which current flows.

21. A method according to any one of claims 16 to 20, wherein: When the determined voltage is within a second voltage value range, the one or more switching components are controlled so that a total circuit resistance of the heating element through which current flows is higher than a total circuit resistance of the heating element through which current flows when the determined voltage is below the second voltage value range.

22. The method of claim 21, wherein: When the determined voltage is within the second voltage value range, the one or more switch components are controlled so that the current flows in series through at least the third heating element and the fourth heating element of the heating elements, thereby increasing the total circuit resistance of the heating elements through which the current flows.

23. The method according to claim 21 or 22, comprising: When the determined voltage is within the second voltage value range, the one or more switch components are controlled so that the current flows through at least one of the heating elements, and when the determined voltage is outside the second voltage value range, the current does not flow through the at least one of the heating elements.

24. The method according to any one of claims 21 to 23, wherein at least a plurality of heating elements are connected in parallel with each other, each of the parallel-connected heating elements being controllable by at least one of the switch components, the method comprising controlling the switch components in response to the signal to configure current to flow through: A first set of heating elements; or a second group of heating elements different from said first group.

25. A method according to any one of claims 16 to 24, wherein the hair styling appliance comprises: A first heater includes a plurality of heating elements; and a second heater includes a plurality of heating elements, the method including controlling the first heater independently of the second heater.

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