Specifications

105
Pilot lamp : It is used to indicate the flow of current. The lamp condition and its indication are
given in table II.
Lamp condition
Glowing The temperature is within
predetermined value and the current
is flowing
Not glowing The temperature is more than the
predetermined value and the current
is not flowing.
Indication
9.5 DIFFERENCES BETWEEN NON-AUTOMATIC AND AUTOMATIC IRON BOX:
Sl. No Non-automatic type Automatic type
1
It does not consist of thermostat
switch. So temperature is not
regulated
It consists of thermostat switch to regulate the
heat to a predetermined value.
2
User has to switch ON or OFF the
supply to iron box as per the heat
requirement.
The thermostat switch disconnects the supply
when predetermined value of temperature is
reached and reconnects the supply when the
iron cools down.
3
There is no pilot lamp to indicate the
temperature condition whether it is
within the limit or not
It has pilot lamp to indicate. It will glow if the
temperature is within predetermined value.
Otherwise not glow.
4
Cost is low Cost is high
5
Overheat may burn the cloth. So
more care is required.
As the temperature is controlled automatically
by thermostatic switch, no such risk is involved.
9.6 STEAM IRON:
Electrically there is no difference between steam irons and dry irons. A steam iron has a
small reservoir mounted above the heating element. A control valve on this allows the water to
drip slowly into recess in the sole plate. Check valve prevents the water and steam going back
to reservoir. When the water drips on the hot sole-plate, it is converted into steam and goes out
through the holes in the bottom of the sole-plate. The heating element is concealed with the
sole-plate. The amount of steam can be controlled by the contact knob on the iron located on
the handle. Like automatic iron, a thermostat is also provided to control the temperature. Fig.9.9
shows the diagram of construction of typical steam iron.