A Bimetal Thermostat Manufacturer Shaping the Future

What is a thermostat?

Thermo-stat

The word “thermostat” is derived from two parts: “thermo,” referring to heat or temperature, and “stat,” meaning to keep something stable or constant. In simple terms, a thermostat is a temperature-control device that senses temperature and automatically maintains it at a preset level or prevents overheating.

Purpose

   

Asahi thermostats are bimetal thermostats.

A bimetal thermostat is a temperature-sensitive switch that detects temperature changes and opens or closes an electrical circuit (ON/OFF) to control temperature and prevent overheating. Asahi Keiki offers a wide range of bimetal thermostats, including models rated up to 290°C, automatic-reset and manual-reset types, waterproof and hermetically sealed designs, compact models, and low-temperature models suitable for operation at −20°C (ON).

What are the principles of bimetal?

The principle of a bimetal is based on the fact that two different metals have different coefficients of thermal expansion. When the temperature changes, the metals expand or contract at different rates, causing the bimetal strip to bend or twist. This characteristic makes bimetals widely used in temperature detectors and temperature control devices. For example, in a thermostat, the bimetal disck bends in response to a specific temperature and opens or closes an electrical circuit to control temperature. Other applications include thermometers, fire alarms, and overheat protection devices. This operation of bimetal is highly reliable and provides a simple yet effective mechanism for a wide range of applications.

• • Bimetal

    Bimetal: A single, rolled sheet formed by the permanent bonding of two different metal layers.

• • Etymology

    Derived from the prefix "bi-" (meaning "two"), "bi-metal" refers to the combination of two distinct metals.

• • Bonding

    The two layers are joined through cold or hot rolling processes, forming a permanent metallurgical (atomic) bond without adhesives.

• • Materials

    The high-expansion side consists of an iron (Fe) and nickel (Ni) alloy, with small amounts of metals such as Cr, Mn, and Mg. The low-expansion side is Invar (Ni36-Fe). In other words, the principal components of both the high-expansion and low-expansion sides are iron and nickel.

• • Temperature Bending Action

    The bi-metal strip bends in one direction as the temperature rises, and reverses its bend as the temperature falls.

• • When its movement is restrained, the bimetal generates [force] proportional to the degree of restraint.

    In a thermostat, this force is used to overcome the contact pressure and operate the switching contacts.

How a Bimetal Thermostat Works

Structures of bimetals Thermostat.

Types and Purposes of bimetals.

Types and Structures

Applications