Hair styling appliance

Abstract

A hair styling apparatus includes a plurality of heater electrodes which heat one or more hair styling heaters, a power source for powering the plurality of heater electrodes and a controller configured to control powering of the plurality of heater electrodes from the power source. The plurality of heaters includes a first subset and a second subset of heaters. The controller is configured to, in a first mode of operation; control the power source so that the first and second subsets are not simultaneously powered.

1 . A hair styling apparatus comprising:
 a plurality of heater electrodes which heat one or more hair styling heaters, the plurality of heater electrodes comprising a first subset and a second subset;   a power source for powering the plurality of heater electrodes and   a controller configured to control powering of the plurality of heater electrodes from the power source;   wherein, in a first mode of operation, the controller is configured to control the power source so that the first and second subsets of the plurality of heater electrodes are not simultaneously powered and are powered in a time interleaved manner multiple times per second.   
     
     
         2 . (canceled) 
     
     
         3 . A hair styling apparatus according to  claim 1 , wherein the controller is configured to select the first and second subsets so that a total current drawn by each of the first and second subsets is below a predetermined current threshold. 
     
     
         4 . A hair styling apparatus according to  claim 1 , wherein no heater electrodes are selected for both the first and second sub sets. 
     
     
         5 . A hair styling apparatus according to  claim 4 , wherein the controller is configured to switch the power source between the first and second subsets. 
     
     
         6 . A hair styling apparatus according to  claim 5 , wherein the controller is configured to switch between each subset multiple times per second. 
     
     
         7 . A hair styling apparatus according to  claim 1 , wherein the controller is configured to alternate between the first mode of operation and a second mode of operation in which the first and second subsets of the plurality of heater electrodes are simultaneously powered. 
     
     
         8 . A hair styling apparatus according to  claim 7 , wherein the controller is configured to switch from the second mode of operation to the first mode of operation in response to a control signal. 
     
     
         9 . A hair styling apparatus according to  claim 8 , wherein the control signal is that a predetermined amount of time in the second mode of operation has elapsed. 
     
     
         10 . A hair styling apparatus according to  claim 7 , wherein the power source is a battery source and the hair styling apparatus further comprises a battery temperature sensor which senses the temperature of the battery source and which sends a battery temperature sense signal to the controller. 
     
     
         11 . A hair styling apparatus according to  claim 10 , wherein the battery temperature sense signal is compared to a battery temperature threshold and the control signal is generated when the battery temperature sense signal is greater than the battery temperature threshold. 
     
     
         12 . A hair styling apparatus according to  claim 11 , wherein the battery temperature threshold is in the range of 60 to 80 degrees C., more preferably 70 degrees C. 
     
     
         13 . A hair styling apparatus according to  claim 7 , further comprising a temperature sensor sensing ambient temperature; and said control signal is generated when the sensed ambient temperature is below a threshold ambient temperature. 
     
     
         14 . A hair styling apparatus according to  claim 13 , wherein the ambient temperature threshold is in the range of 25-35 degrees C. 
     
     
         15 . A hair styling apparatus according to  claim 1 , comprising a first arm having a first contacting surface and a second arm having a second contacting surface, wherein the arms are moveable between a closed position in which the first and second contacting surfaces are adjacent and an open position in which the first and second contacting surfaces are spaced apart. 
     
     
         16 . A hair styling apparatus according to  claim 15 , wherein the first arm comprises a first hair styling heater having a plurality of heater electrodes. 
     
     
         17 . A hair styling apparatus according to  claim 15 , wherein the first arm comprises a first hair styling heater and the second arm comprises a second hair styling heater and each hair styling heater comprises at least one heater electrode. 
     
     
         18 . A hair styling apparatus according to  claim 1 , comprising a touch sensitive switch configured to enable or disable the hair styling apparatus. 
     
     
         19 . A hair styling apparatus according to  claim 18 , comprising a first arm having a first contacting surface and a second arm having a second contacting surface, wherein the arms are moveable between a closed position in which the first and second contacting surfaces are adjacent and an open position in which the first and second contacting surfaces are spaced apart, wherein the touch sensitive switch is located on the first or second contacting surface. 
     
     
         20 . A hair styling apparatus according to  claim 18 , wherein when the arms are in the closed position, the touch sensitive switch is deactivated. 
     
     
         21 . A hair styling apparatus according to  claim 18 , wherein the controller is configured to determine when a user has activated said touch sensitive switch for at least a predetermined duration of time and enable or disable the hair styling apparatus responsive to said determining. 
     
     
         22 . A hair styling apparatus according to  claim 1 , wherein the or each heater comprises a heater plate which is mounted on a thermally insulating support structure. 
     
     
         23 . A hair styling apparatus according to  claim 22 , wherein the heater plate comprises at least one recess which cooperates with a corresponding projection on the thermally insulating support structure. 
     
     
         24 . A hair styling apparatus according to  claim 22 , wherein the thermally insulating support structure is resiliently mounted within an arm of the hair styling apparatus. 
     
     
         25 . A hair styling apparatus according to  claim 1 , wherein the power source is a battery source. 
     
     
         26 . A hair styling apparatus according to  claim 1 , wherein, in the first mode of operation, the controller is configured to control the powering of the heater electrodes using predefined heating cycles during one or more of which power is provided, at different times, to the first and second subsets of the plurality of heaters, and preferably wherein the heating cycles have a duration of between 100 μs and 500 ms. 
     
     
         27 . A hair styling apparatus according to  claim 1 , wherein the controller is configured to use pulse width modulation, (PWM), power control to control the delivery of power to the first and second subsets such that, during the first mode of operation, the controller is configured to generate power control signals for the first and second subsets to cause power to be delivered to the first and second subsets at different times within each of one or more heating cycles of the PWM power control. 
     
     
         28 . A method of controlling a hair styling apparatus comprising a plurality of heater electrodes which heat one or more hair styling heaters, the plurality of heaters comprising a first subset and a second subset; the method comprising:
 controlling powering of the heater electrodes so that the first and second subsets of the plurality of heaters are not simultaneously powered and are powered in a time interleaved manner multiple times per second.   
     
     
         29 . A controller for a hair styling appliance, wherein the controller configured is configured to implement the method of  claim 28 .