MF-R250U-2

PTC Resettable fuses are an effective over-temperature protection component, used in numerous safety-critical designs. As the name suggests, this type of fuse is designed to “reset” its electrical properties upon removal and reapplication of power. Despite the name, a PTC resettable fuse doesn’t necessarily need to be of fuse-like composition; in fact, some PTC resettable fuses are made of a range of materials, such as ceramic and silicone.

The MF-R250U-2 is one such PTC resettable fuse, with an application field that is very broad. Commonly, it is integrated into various home appliances, such as TVs, computers, washers, dryers, ovens, and other consumer grade electronics. As expected, the MF-R250U-2 has its own unique inner working principle. It utilizes what is commonly known as a “negative temperature coefficient” (NTC) material, which is basically a type of resistive material that has electrical characteristics that vary depending on the temperature. When this temperature is above its rated level, the material’s resistance increases, causing the circuit to open and thus protecting the connected components from harm.

As is the case with all PTC resettable fuses, the MF-R250U-2 utilizes two important stages of electrical protection. The first is known as the “self-healing” stage, seen when the temperature rises and the electrical resistance of the NTC material increases, as previously mentioned. This causes the circuit to open, thus protecting the connected equipment from harm. In the second stage, once the temperature has reduced, the NTC material’s resistance decreases and the fuse “resets” itself, allowing power to continue to flow through the circuit. The MF-R250U-2 has a maximum current rating of 250mA, a maximum voltage rating of 5V, and a temperature range of -30°C to +105°C.

Overall, the MF-R250U-2 is a reliable and effective over-temperature protection component, with a broad application range and a workable inner working principle. It utilizes the latest NTC material to help protect connected components from harm, whilst still being able to “reset” its electrical properties after temperature reduction. As expected from a PTC resettable fuse, the MF-R250U-2 has a maximum current rating of 250mA, a maximum voltage rating of 5V, and a temperature range of -30°C to +105°C.