In order for the iron to start heating, the supply voltage must be applied to a tubular electric heater (TEN), pressed into the sole of the iron. For quick heating of the sole, heating elements of high power are used, from 1000 to 2200 W. If this power is supplied constantly, then in a few minutes the sole of the iron will be warmed up red-hot and it will be impossible to iron things without spoiling them. For ironing products made of nylon and anida, the temperature of the iron is 95-110 ° C, and that of linen is 210-230 ° C. Therefore, to set the required temperature when ironing items made of different fabrics, there is a temperature control unit.
The temperature control unit is controlled with a round knob located in the central part under the iron handle. Turning the knob clockwise will increase the heating temperature; turning it counterclockwise will lower the heating temperature.
Rotation from the handle to the thermostat assembly is transmitted through an adapter in the form of a sleeve or a metal angle put on a stem with a thermostat thread. The handle on the iron body is held by several latches. To remove the handle, it is enough to pry it over the edge with a slight force with a screwdriver blade.
The thermoregulator of the Philips iron and any other manufacturer is ensured by the installation of a bimetallic plate, which is a strip of two metals sintered together over the entire surface with different coefficients of linear expansion. As the temperature changes, each of the metals expands to a different extent and as a result, the plate bends.
In the thermostat, the plate is connected to a bistable switch through a ceramic rod. The principle of its operation is based on the fact that, due to a flat curved spring, when passing through the equilibrium point, the contacts instantly open or close. Speed is necessary to reduce burning of contacts as a result of the formation of a spark when they open. The switching point of the switch can be changed by turning the knob on the iron body and thus controlling the heating temperature of the soleplate. When turning the thermostat switch on and off, a characteristic low click is heard.
Devices that fix and at the same time regulate the set temperature value are mostly found in production. But they also found their place in everyday life. To maintain the required microclimate in the house, thermostats for water are often used. They make such devices for drying vegetables or heating an incubator with their own hands. A similar system can find its place anywhere.
In this video we will find out what a temperature controller is:
In reality, most thermostats are only part of the overall circuit, which consists of the following components: