Living in a modern life, it seems not to be difficult for us to control the temperature in our house. When it’s hot or cold, all that you just do is to adjust a thermostat to increase or decrease the temperature. Do you think that it’s so amazing and wonderful? Have you ever wondered how does the best thermostat perform?
Well, a mechanical thermostat is truly a very simple instrument. It is typically a thermometer attached to a switch that will turn on your heater, whether your heat source is electricity or natural gas. If you move away the cover of the thermostat, you will watch the inner workings and know better.
Let’s see what it is
The top layer will hold a thermometer coil and a mercury switch. The mercury switch is just a small vial area with the liquid metal – mercury. Within this vial are three wires, including one at the bottom of the vial, one at the right of the vial, and one at the left of the vial. So, when the temperature cools or rises, the vial of mercury gets tipped to the left or the right making the corresponding wire come into contact with the wire that runs along the bottom. In case that the mercury gets tipped to the left, a connection is made that forms a current energize a relay that begins the heater and circulation fan. When the room heats up, the vial levels off and if it is in balance, the connection will be broken to turn off the heater. If the mercury switch is titled to the right, another relay will turn on the air conditioner.
What tips the vial in either way is the thermometer coil that rests against the vial of mercury. The thermometer coil is built on a bi-metallic strip made of two different kinds of metal (often iron and copper) that are connected. Since the different metals respond to heat at different levels, this strips will contact and spread causing the coil to curl up and uncurl as the temperature alters. Normally, this curling or uncurling tilts the mercury vial, and then signals the heating source to kick off or on. When controlling the temperature to knob the thermostat, please monitor the tightness of the coil.
Below the top layer of this device, you can watch the circuit board that houses the wires can lead to the heat source and circulation fan. The circuit board is linked to the mercury switch via a metal screw and wire that can “read” the switch and turn on the suitable cooling and heating system.
Nowadays, you can find out digital thermostats on the market. These instruments differ from the mechanical thermostats in that they avail a thermistor and a resistor. The microcontroller in the digital thermostat will measure the resistance and transfer that number to a temperature reading. Well, they are able to save energy because the might be programmed to turn the AC or heat on or off at any time in a day. For instance, you might set the AC to turn on an hour before you return home from work or control the heater remain off during the hours while you are not at home and then turn it on an hour before you come back.