Working Principle of Hair Dryer Temperature Control Switch

The temperature control switch of a hair dryer is generally controlled by a bimetallic temperature controller. The bimetallic temp-

erature controller mainly consists of a bimetallic strip and a contact switch. 

The shape of the bimetal strip changes with the temperature. When the temperature is in a normal state, the contacts of the bimetal 

are closed. When the temperature rises and reaches the sensing temperature of the bimetal strip, the bimetal strip deforms and the 

contacts open to realize temperature control.

When the hairdryer is off, the two contacts of the bimetal temperature controller ST are on. When the hairdryer is energized and rises 

to the high temperature zone, the hairdryer works normally. When a certain temperature is reached, if the two contacts of the bimetal 

temperature controller separate and enter the disconnected state, the hairdryer will stop heating and enter the heat preservation state. 

When the temperature drops to a certain temperature, the metal shrapnel of the bimetal temperature controller re-conducts electricity 

and can continue to heat.

How to use the hair dryer correctly

1. After washing your hair, wipe off excess water with a dry towel, then part your hair and secure the outer hair on top of your head with 

a clip. Because this will dry your hair better.

2. remove the hair from the top of the head, part it into two sections and dry it, comb it with your hands by inserting them into the hair 

and then blow dry it with a hair dryer.

3. Separate the bottom half of the hair into two sections, spread 5 fingers into the hair, and comb through the hair with your fingers from 

the crown to the ends while blow-drying with a hair dryer.

4. Divide the side hair into two sections by the ears. Comb the hair slowly from root to tip with a roller brush and place the hair dryer on 

the side. Treat the hair behind the ear in the same way.

Use and maintenance of the hair dryer

(1) The hair dryer must be used at the power supply voltage specified on the nameplate. For hair dryers using a three-core power cord, 

the grounding wire should be properly connected.

(2) When using the hair dryer, the air inlet and outlet must be kept unobstructed, otherwise the effect will not be achieved and the app-

liance will be burnt due to overheating.

(3) When used to blow dry wet hair, the air outlet of the hair dryer should be kept at a certain distance (not less than 50mm) from the 

hair to prevent the air outlet from being blocked and scalding the hair. At the same time, to avoid blow-drying hair produced by the 

water vapor affects the insulation strength and cause leakage, so maintain a certain distance is very important for safety.

(4) Before using the hair dryer, try to switch the hair dryer from the "hot" state to the "cold" state by cutting off the power supply of the 

heating element first. Then let the residual heat of the electric heating element blow out with the help of cold air, so that the internal te-

mperature of the hairdryer will be reduced, and then cut off all power supplies. This can delay the aging of the internal insulation layer of 

the hairdryer and extend its service life. At the same time, it is not easy to put on the table to burn other things.

(5) Hairdryer continuous use of time as far as possible not too long, should be used intermittently, to prevent the heating element 

and motor overheating burned. The hairdryer should be placed in a dry place when not in use, not in the open air or in a damp place. 

When you take it out after long-term use, you should check the insulation resistance first. It can be used normally only after meeting 

the requirements to ensure personal safety during use. Due to the high level of dust in the air, although many hair dryers are equipped 

with filters at the air inlet for protection, they are not able to prevent dust with very small particles, and not all hair dryers are equipped 

with filtering cloths. Therefore, dust must be cleaned regularly to prevent clogging of air ducts and damage to parts.

(6) Do not throw the hair dryer. Mechanical shocks can damage the heating element and motor. Also, do not disassemble it easily 

to avoid damaging the parts. In order to ensure the normal use of the hairdryer, the bearing parts and other rotating parts of the 

motor should be regularly filled with lubricating oil, but the amount of oil should not be too much, so as not to flow into the coil 

and cause failure.