Thermostat pdf explanation

1. MRS. A. REHANA BARVEEN
DEPARTMENT OF PHYSICS
E.M.G.YADAVA WOMEN’S COLLEGE, MADURAI.

2. A THERMOSTAT is a
regulating device
component which
senses the temperature
of a physical system
and performs actions
so that the system's
temperature is
maintained near a
desired setpoint.

3. ▪A Thermostat is a device by means of
which the temperature of a bath or
any closed space is maintained at any
desired temperature for a long time.

4. ▪Automatically cuts off the heat
supply.
▪If the temperature falls below the
required level, heat supplied is
immediately.

5. ▪Bimetallic Thermostat.
▪Liquid Thermostat.
▪Thermometer type of Thermostat.
▪Vapour Pressure Thermostat.

6. AB-Bimetallic
Strip obtained by
melting together
brass and invar
strip.
H-Heating Coil.
E-Electric Heater.

7. ▪When contact is made between C and D,
Current flow through H.
▪The temperature in the electric heater
increases.
▪Brass Strip expands more than the invar part.
▪Therefore, due to unequal expansion the
Bimetallic Strip bends upwards.

8. ▪This breaks the contact between C and D
and the current through the circuit stops.
▪The temperature falls below the
described limit, the Bimetallic Strip cools
and becomes straight.
▪Heating of the enclosure is resumed.