Specifications
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Heating element: The heating element in most hair dryers is a bare, coiled nichrome wire
that’s wrapped around insulating mica boards as shown in Fig. 13.10
Nichrome wire is an alloy of two metals, nickel and chromium. This alloy is used in heating
elements in a number of household products, from curling irons to toasters. Nichrome wire has
two features that make it a good producer of heat:
It’s a poor conductor of electricity compared to something like copper wire. This gives
the alloy enough resistance to get hot from all of the current flowing into it.
It doesn’t oxidize when heated. Other metals like iron rust pretty quickly at the
temperatures used in toasters and hair dryers.
The heating element is of the open wire type, wound on thin mica insulating board. Something
seen more often these days are hair dryers with a ceramic coating on the heating element.
Coming in a variety of different configurations, ceramic-coated heating elements are said to
heat more evenly and effectively. It’s also popular to infuse the ceramic with materials such as
crushed tourmaline, which is said to support the creation of ions and ideal heat flow.. The majority
of hair dryers seem to use a three-section heating element (low, medim and high heating element)
controlled by a selector switch.
Fig.13.9 - Hair dryer motor Fig.13.10 - Heating element
Thermostat Switch : Each heating element has special thermostat stip mounted near the air
nozzle which senses the temperature of the air flow. The thermostat switch is normally closed
and is ipen if the hot air blown outside the heated circuit becomes too hot. A fuse may be found
connected in series btween the temperature control switch and the heater element.
Selector switch : As the majority of hair dryers seem to use a three-section heating element(low,
medim and high heating element) controlled by a selector switch, the switch will have three
positions – low, medium and high to select the heating element as per the requirment. The
selector switch will always be connected to the motor and then to the heater circuit so that the
heating element cannot be turned on unless the motor is running.
The diagram showing electrical connection of motor, selector switch and heating element
are shown in Fig. 13.11.