temperature sensor and thermostat

hi,
Can any body tell me,what is difference between temperature sensor and thermostat?. I heard that thermostat is Temperature sensing device that turns an appliance or circuit on or off when a particular temperature is reached. Why i should use thermostat, if am reading the temp value in micro controller continuously through ADC and if temp goes abnormal through relay i am turning on/off the device. Can any body clear my simple doubt.

A temperature sensor is something used to give an output proportional to the temperature of it's surroundings whilst a Thermostat detects a threshold temperature to activate switch contacts, ~ generally!

Yes, you could use a temperature sensor with an ADC to detect a given temperature and then use that to control relays via a controller, but you may find that using the same temperature value causes some 'cycling' effects where a thermostat which has built in hysteresis is less prone to this effect.
Programming of your controller can be used to avoid 'cycling' with options of having a manual reset for example after 'over-temperature' occurs rather than your system re-setting and the cycle repeating should you have a fault condition which needs intervention.
A Thermal switch could be used directly into an input of a controller without an ADC as it has an internal make or break contact. same option for a reset function.

Do an internet search for each device and you will get much more information

hope this assists
Mik

Thermostat is a component of a control system which senses the temperature of a system so that the system's temperature is maintained near a desired set point. The thermostat does this by switching heating or cooling devices on or off, or regulating the flow of a heat transfer fluid as needed, to maintain the correct temperature.

Temperature sensor is sensing temperature only..

zakir_cool

something which would really assist with best answering your question would be a description of what it is that you are trying to do.

As an example, I use temperature sensors on heatsinks of Audio Amplifiers to control the voltage supplied to fans for cooling; but in case of obstructed airflow then to protect from overheating I use a Thermal Switch to shut down the amplifier when an 'over-temperature' occurs which has the manual reset so that the blockage to airflow can be resolved prior to re-starting

Mik

a thermostat contains a temperature sensor and switches a relay when the temperature sensor detects a certain temperature level.
a temperature sensor only measures the temperature and need some other components to do something with that temperature measurement.