Appliance to which one of a plurality of magnetic attachments is attachable

Abstract

An appliance has a main unit with a number of magnetic attachments, attachable in a variety of rotational positions relative to the main unit about an axis, a magnetometer, and a control module. The control module determines which of the attachments is attached to the main unit based on data output by the magnetometer. The appliance can have the following features: (i) the magnetometer located on the axis; (ii) the appliance with the plurality of magnetic attachments, each with a plurality of magnetic regions distributed about the axis in a rotationally symmetric arrangement, and the magnetometer is located radially inwardly of the plurality of magnetic regions when the attachment is attached to the main unit; and (iii) the appliance with the magnetic attachments and each magnetic attachment has a magnetic region located on the axis when the attachment is attached to the main unit.

1 . An appliance comprising:
 a main unit to which one of a plurality of magnetic attachments is attachable in any one of a plurality of rotational positions relative to the main unit about an axis;   a magnetometer; and   a control module operable to determine which of the plurality of attachments is attached to the main unit based on data output by the magnetometer;   wherein the appliance comprises one or more of the following features:
 (i) the magnetometer is located on the axis; 
 (ii) the appliance comprises the plurality of magnetic attachments, each magnetic attachment comprises a plurality of magnetic regions distributed about the axis in a rotationally symmetric arrangement, and the magnetometer is located radially inwardly of the plurality of magnetic regions when the attachment is attached to the main unit; and 
 (iii) the appliance comprises the plurality of magnetic attachments and each magnetic attachment comprises a magnetic region located on the axis when the attachment is attached to the main unit. 
   
     
     
         2 . The appliance according to  claim 1 , wherein the appliance comprises an electric component and the control module is operable to control the electric component in response to the determination and, wherein the electric component comprises an electric motor or a heater, and the control module is operable to control a speed of the electric motor or a temperature of the heater in response to the determination. 
     
     
         3 . (canceled) 
     
     
         4 . The appliance according to  claim 2 , wherein the electric component comprises a sensor, and the control module is operable to control a setting of the sensor in response to the determination. 
     
     
         5 . The appliance according to  claim 1 , wherein the appliance comprises an airflow generator for drawing an airflow through the appliance, and the control module is operable to control a characteristic of the airflow in response to the determination. 
     
     
         6 . The appliance according to  claim 5 , wherein the control module is operable to control one or more of a flow rate and a temperature of the airflow. 
     
     
         7 . The appliance according to  claim 1 , wherein the appliance is a hair appliance comprising a plurality of flow and heat settings, and the control module is operable to select one of the settings based on the determination. 
     
     
         8 . The appliance according to  claim 1 , wherein the appliance comprises the plurality of magnetic attachments, and the magnetic attachments differ in the magnetic field that each magnetic attachment produces at the magnetometer when the attachment is attached to the main unit. 
     
     
         9 . The appliance according to  claim 8 , wherein the magnetic field that each magnetic attachment produces at the magnetometer has a component parallel to the axis, and the component differs for different magnetic attachments. 
     
     
         10 . The appliance according to  claim 8 , wherein the magnetic attachments each comprise a plurality of magnetic regions, each magnetic region has a positive or negative polarity in the direction of the magnetometer when the magnetic attachment is attached to the main unit, and the magnetic attachments differ in the arrangement of magnetic regions having positive and negative polarities. 
     
     
         11 . The appliance according to  claim 10 , wherein the differing arrangements of magnetic regions comprises a differing ratio of magnetic regions having a positive polarity in the direction of the magnetometer to magnetic regions having a negative polarity in the direction of the magnetometer, when the magnetic attachment is attached to the main unit. 
     
     
         12 . The appliance according to  claim 1 , wherein the magnetic regions are distributed around the circumference of a circle that is centred on the axis when the magnetic attachment is attached to the main unit. 
     
     
         13 . The appliance according to  claim 10 , wherein the magnetic regions are provided by polarised portions of a bonded magnet, and/or, wherein the magnetometer is located on the axis and a distribution of the polarities of the magnetic regions is rotationally asymmetric about the axis. 
     
     
         14 . (canceled) 
     
     
         15 . The appliance according to  claim 1 , wherein the magnetometer is located on the axis and wherein, when one of plurality of magnetic attachments is attached to the main unit, the control module is operable to additionally determine a rotational position of the magnetic attachment relative to the main unit based on data output by the magnetometer. 
     
     
         16 . The appliance according to  claim 15 , wherein the magnetic field produced by the magnetic attachment at the magnetometer when attached to the main unit has a component perpendicular to the axis, and the control module is operable to determine the rotational position of the magnetic attachment relative to the main unit based on an angle of the perpendicular component about the axis and/or wherein the appliance comprises an electric component, and the control module is operable to control the electric component according to the determined rotational position. 
     
     
         17 . (canceled) 
     
     
         18 . The appliance according to  claim 1 , wherein the main unit comprises a barrel section having a central bore, the one of a plurality of attachments is attachable to an end of the barrel section, and the magnetometer is located within the bore, and/or wherein at least one of the plurality of attachments is rotatable relative to the main unit about the axis whilst attached to the main unit, and/or wherein the appliance is a hair appliance. 
     
     
         19 . (canceled) 
     
     
         20 . (canceled)