Temperature switch

A temperature switch is an electronic device that opens or closes the electrical circuit depending on the temperature environment. It consists of a bimetallic strip, a switching contact and a spring.

The bimetallic strip is composed of two metals with different expansion coefficients. When the temperature rise heats the bimetallic strip, the two metals expand differently and the strip bends. This causes the switching contact to open or close, depending on how the temperature switch is set.

If the switching contact is open, no current flows in the circuit. However, if the temperature reaches or exceeds the set threshold value, the bimetallic strip bends and the switching contact closes, allowing the current to flow. This allows the temperature switch to activate or deactivate cooling or heating, for example.

The spring in the temperature switch is used to return the bimetal strip to its original position as soon as the temperature falls below the threshold value again. This opens the switching contact and interrupts the current flow.

Temperature switches are used in various applications such as household appliances, air conditioners, motors, heating systems and many others to monitor the temperature and adjust operation accordingly.

There are different types of temperature switches that can be used depending on the area of application and desired functionality. Here are some examples:

1. Bimetal switch: These switches use two different metals with different expansion coefficients. When heated, the bimetal deforms, causing the switch to switch on or off.

2. Klixon switch: These switches use a bimetallic strip that triggers when a certain temperature is reached and opens or closes the circuit.

3. Thermal switch: These switches use an electrical resistance that changes with increasing temperature. When a certain temperature is reached, the resistance value changes and the switch switches on or off.

4. Reed temperature switch: These switches use a magnetic switch that opens or closes when a certain temperature is reached. They are usually arranged in a glass tube with a reed contact.

5. Liquid-filled temperature switches: These switches contain a liquid that expands when heated and actuates a switch.

These are just a few examples of different types of temperature switches. There are many other variations and specialized switches that can be used depending on the application requirements.

Temperature switches are used in industry to monitor a specific temperature limit and automatically trigger actions if it is exceeded. Here are some examples of the use of temperature switches in industry:

1. Machine monitoring: Many industrial plants contain machines and devices that have to withstand certain temperature limits. Temperature switches are used to ensure that the operating temperature does not become too high and cause damage to the machine.

2. Process control: In certain industrial processes, it is important to keep the temperature within a defined range to ensure quality and efficiency. Temperature switches monitor the temperature and can activate heating or cooling devices as required to maintain the desired conditions.

3. Security systems: In some industrial plants, excessive heating can pose a safety risk, e.g. in chemical plants or power stations. Temperature switches are used to monitor critical temperatures and trigger alarms or initiate emergency shutdowns if they are exceeded in order to prevent damage or accidents.

4. Cooling systems: Temperature switches are also used in refrigeration and air conditioning systems to monitor the temperature of the coolant and control the operation of the compressors or fans to maintain the desired cooling capacity.

5. Temperature compensation: In some industrial processes, it is important to compensate for the effects of temperature fluctuations on measurements or other parameters. Temperature switches can be used to initiate corrective action if the temperature is outside a certain range.

Overall, temperature switches play an important role in industrial automation and safety to monitor temperature conditions and take appropriate action to prevent damage, accidents or quality problems.

The use of temperature switches offers several advantages:

1. Protection against overheating: Temperature switches monitor the temperature in a system and switch it off automatically if the temperature exceeds a certain threshold value. This prevents damage to the system due to overheating.

2. Energy-saving: Temperature switches can be used to automatically switch off devices or systems when they are not in operation or when a certain temperature is reached. This saves energy and extends the service life of the appliances.

3. Early warning: Some temperature switches are equipped with alarm functions that provide an early warning of impending overheating or a rise in temperature. This allows users to react in good time and avoid potential damage.

4. Reliability: Temperature switches are generally robust and reliable. They can be used in different environments and provide accurate and constant temperature monitoring.

5. Versatility: Temperature switches are available in different versions and can be used for a variety of applications. They can be used in household appliances, industrial plants, vehicles and many other areas.

Overall, temperature switches offer an effective way of monitoring and controlling the temperature in a system. They help to prevent damage, save energy and improve the safety and reliability of devices and systems.

The temperature ranges that can be covered by a temperature switch depend on the specific type of switch. There are different types of temperature switches that are designed for different temperature ranges.

Some common temperature switch types and their corresponding temperature ranges are:

- Bimetal temperature switch: These switches react to the expansion of a bimetallic strip that bends at certain temperatures. They can cover temperature ranges from -50°C to several hundred degrees Celsius.

- Thermostats: Thermostats are generally designed for use in household appliances and heating systems. They can cover temperatures from around -10°C to 150°C.

- Compensation temperature switch: These switches use a combination of bimetal and a compensation strip to enable more precise temperature measurements. They can cover temperature ranges from -200°C to several hundred degrees Celsius.

- Digital temperature switches: These switches use sensors such as thermocouples or resistance thermometers and can therefore be used in a wide temperature range. They can cover temperatures from -200°C to several thousand degrees Celsius.

It is important to note that this is only general information and the specific temperature coverage may vary from manufacturer to manufacturer. It is therefore advisable to consult the technical data sheets and instructions for the respective temperature switch in order to obtain precise information.

There are several factors that can influence the accuracy and reliability of a temperature switch:

1. Sensor accuracy: The accuracy of the temperature sensor is crucial for precise temperature detection. The more accurate the sensor is, the more accurately the switch will measure the temperature.

2. Calibration: Accurate calibration of the temperature switch is important to ensure that it provides correct readings. A regular check and possible recalibration may be necessary to maintain a high level of accuracy.

3. Hysteresis: The hysteresis is the temperature difference between switching the switch on and off. A low hysteresis ensures more precise temperature control.

4. Environmental influences: Temperature switches can be influenced by external factors such as electrical fields, vibrations or pressure changes. Good shielding and insulation can help to minimize these influences.

5. Ageing and wear: Over time, temperature switches can become inaccurate due to ageing and wear. Regular maintenance and, if necessary, replacement of components may be required to maintain accuracy and reliability.

6. Ambient temperature: The ambient temperature can influence the accuracy of the temperature switch. Some switches can react sensitively to temperature fluctuations and their accuracy can decrease at extreme temperatures.

7. Switching time: The switching time refers to the time required by the switch to react to a change in temperature. A fast switching time is important to enable precise temperature control.

It is important to note that the accuracy and reliability of a temperature switch can depend on various factors and careful selection, installation and maintenance is required to achieve optimum results.