Longde Science Popularization: The Role of Temperature Fuses in Circuits

What is a temperature fuse

Temperature fuses, also known as thermal fuses or thermal melt fuses, are safety devices used to protect circuits or equipment. They are specially designed resistance wires that can automatically disconnect the circuit based on the magnitude of the current and the duration of time, serving the purpose of overload protection.

2023-08-12

The working principle of temperature fuses

When current flows through a conductor, the conductor will heat up due to its certain resistance. The amount of heat generated follows this formula: Q=0.24I2RT; where Q is the amount of heat generated, 0.24 is a constant, I is the current flowing through the conductor, R is the resistance of the conductor, and T is the time the current flows through the conductor; from this formula, we can easily see the simple working principle of a fuse.

2023-03-11

What is used to sense temperature in a temperature control switch?

Many friends are very interested in what temperature sensing the snap-action temperature control switch relies on! Since it is a snap-action temperature control switch, it must have its own temperature sensing system. Without a good temperature sensing system, it is impossible to predict the temperature.

2020-07-15

Longde Electric teaches you how to use the thermostat correctly.

The use of electric heating systems in homes is increasing, and how to save energy has become a concern for many people. In addition to ensuring good insulation in the house, temperature control is one of the keys to energy saving. Some users who have installed electric heating always turn on the thermostat when needed and turn it off when they go out, thinking that this will save electricity. In fact, this not only does not save energy but also consumes more energy. So how can we use the thermostat to truly save energy? Let's learn from the editor of Longde Electric.    1. Is turning it on when needed energy-saving?   Turning on the thermostat when needed and turning it off when going out will consume energy. The electric heating system operates at low temperatures and has good heat storage capabilities. After the system is turned on, it takes some time for the room temperature to reach the set temperature, and when the system is turned off, the indoor temperature does not drop rapidly. When turned back on, it also takes a long time to raise the temperature again. Frequent switching not only does not achieve energy-saving effects but also increases the operating costs of the heating system.     Rooms that are not frequently used can have their temperature lowered a few degrees through the thermostat. When leaving the house for a long time, simply lower the thermostat temperature a few degrees. In cases where the house is unoccupied for a long time or when leaving for an extended period, the system can be turned off. However, it is important to note that if there are devices in the room that are at risk of freezing, the temperature should be maintained at a certain level to prevent damage to the equipment or pipes.   2. Does setting the thermostat to a high temperature heat up quickly?   Some users feel that the room temperature is low and set the thermostat to a higher temperature to heat up quickly, which is also incorrect. The time it takes for the room temperature to rise depends on the temperature difference between indoors and outdoors, as well as the installed power per unit area of the room. With a constant installed power and temperature difference, regardless of how high the setting is, the time it takes for the room to reach the desired temperature remains the same. If the room is currently at 16 degrees and you want to raise it to 18 degrees, setting the thermostat to 18, 20, or 25 degrees will take the same amount of time to reach 18 degrees.   Set the thermostat to the desired temperature, or use a smart thermostat that can automatically calculate the pre-heating time.

2020-07-15

What types of fuses do you know?

There are many types of fuses, classified by protection form, usage range, size, rated voltage, breaking capacity, melting speed, etc. Below is an introduction based on type classification, which can be divided into: current fuses: chip fuses, micro fuses, plug fuses, tubular fuses; temperature fuses: RH square type, RP resistance type, RY metal shell; self-resetting fuses: plug-in, stacked, chip.   1. Current Fuses. 1. Chip Fuses. Available in specifications such as 0805, 1206, using thin film technology to control electrical characteristics. Due to their small size, they are ideal for providing secondary protection in circuits with limited space, such as handheld portable electronic devices and various instruments. 2. Tubular Fuses. These are very common, especially in various power applications such as switch power supplies. 3. Plug Fuses. Commonly seen in automotive applications, sometimes also called fork fuses. 4. Micro Fuses.   2. Temperature Fuses.  Temperature fuses, also known as thermal fuses (National Standard GB9816.1-2013), are temperature sensing circuit interruption devices. Temperature fuses can sense overheating caused by abnormal operation of electrical and electronic products, thereby cutting off the circuit to prevent fire hazards. They are a type of non-recoverable disposable thermal protection device, with series such as RH, RF, RY, featuring a compact appearance, good sealing, sensitive and reliable action temperature, minimal impact from current surges, and resistance to vibration. They are mainly used in electric fans, rice cookers, electric frying pans, sterilizers, etc.   1. RH Square Temperature Fuse. The appearance is a plastic square shell, square temperature fuse, generally made of low melting point alloy. 2. RY Metal Shell Temperature Fuse. Made with a metal shell and organic chemical substances as the thermal sensing element, it is sensitive, accurate in action, with a sealed structure and reliable performance. Used in rice cookers, hair dryers, motors, etc. 3. RP Resistance Type Temperature Fuse, generally made of low melting point alloy.     3. Self-Resetting Fuses. This is a type of fuse that automatically resets when the circuit is open due to excessive current, belonging to the reusable type, suitable for overload protection circuits. 1. Plug-in Self-Resetting Fuse. 2. Chip Self-Resetting Fuse. 3. Stacked Self-Resetting Fuse.

2020-07-15

Key points for selecting fuses

When choosing a fuse, I believe everyone finds it quite troublesome, as there is no good guidance. Below, the editor from Longde Electric will list the factors involved in fuse selection, so that everyone can choose a suitable fuse based on these ideas.

2020-07-15