B59950C0120A070

PTC resettable fuses look and function quite differently from traditional resettable fuses. The B59950C0120A070 is a PTC resettable fuse designed for a range of applications. This particular model is a thermal-activated fuse, meaning that its purpose is to prevent current overloads. It has a rated current of 10A and a nominal voltage of 70V DC.

Application Field

PTC resettable fuses like the B59950C0120A070 are often used in applications such as computers and consumer electronics. They are especially useful in these applications because they can protect against current overloads without the user having to replace a fuse each time there is an overload. They are also ideal for powering RF systems and other sensitive components, where an unexpected overvoltage spike can damage regular fuses.

In addition, PTC resettable fuses are used in home appliances such as toasters and microwave ovens. This is because it can provide protection from dangerous electrical problems and in the event of an overload, the PTC resettable fuse will cut off the electricity, protecting the device from further damage.

Working Principle

The working principle of the B59950C0120A070 PTC resettable fuse is based on the thermal expansion of a conductive polymer. The device contains a thermistor element comprising of a conductive polymer that, when heated, expands its crystal structure and, as a result, increases in resistance. This thermistor element is connected in series with the load.

When an overload occurs, the current flowing through the thermistor element increases and causes the thermistor element to heat up. As the thermistor element heats up, its resistance increases, leading to an even greater increase in temperature. Eventually, the temperature of the thermistor element will reach a point where its resistance exceeds the current rating of the PTC resettable fuse. When this happens, the thermistor element will open and the current will be cut off.

Once the current is cut off, the thermistor element will begin to cool down. As it cools down, its resistance will decrease, and eventually it will be low enough that it can conduct current again. When it does, the overload will be eliminated and the PTC resettable fuse will reset itself, allowing the current to flow again.

Conclusion

The B59950C0120A070 PTC resettable fuse is a thermal-activated fuse designed to protect electronic circuits from current overloads. It is widely used in computers and consumer electronics, as well as in home appliances such as toasters and microwave ovens. It works by using a thermistor element that, when heated, increases in resistance and cuts off the current, resetting itself when the temperature decreases.