RUEF400-1

PTC resettable fuses are a type of fast-acting current protection devices used in a wide range of applications to protect connected electrical circuits and components from damage due to excessive current. One of the most popular models of PTC resettable fuses is the RUEF400-1. This article looks at the application field and working principle of this device.

RUEF400-1 resettable fuses are designed primarily for use in low-voltage DC circuits that require precise current control and/or protection against short-circuits. The fuses are not only suitable for stand-alone circuits but can also be wired in parallel to provide increased current capacity in higher amperage applications. Common application fields of this device include LED lighting, low-voltage battery-operated electronics, industrial control and protection circuits, automotive electronics, consumer electronic gadgets, and virtually any other DC system that needs reliable over-current protection.

The RUEF400-1’s resettable fuse characteristics can be adjusted through two control settings – maximum current rating (up to 2.2A) and time-delay (60ms to 100ms). The current rating will not exceed the set safe value in case of overload or short-circuit, whereas the time-delay will prevent the fuse from over-responding to inrush currents when powering up the connected circuit.

The RUEF400-1 resettable fuse works on the principle of positive temperature coefficient(PTC). In a normal situation, the fuse element passes the current thereby maintaining its temperature at a safe value. But, if overload or short-circuit occurs, the current within the fuse element increases causing it to overheat and thermally-expand. This change in size closes the fuses contact gap and interrupts the current flow, thus protecting the circuit from damage.

The RUEF400-1 resettable fuse is a robust, simple, and cost-effective device that can be used in a wide range of applications. Its adjustable characteristics enable accurate control of the safe current level and time-delay, making it an ideal choice for reliable over-current protection.