PTC Resettable Fuses

PTC Resettable Fuses, commonly referred to as polyfuse, are a type of fuse that resets itself after a current overload or fault. The PTC Resettable Fuses are designed to be low cost, easily integrated solutions for circuit protection against over-current faults. They are used to protect consumer electronic circuits and applications where controlling the current and voltage is critical. The PFRA.185.3 is a particular type of PTC Resettable Fuse developed by TE Connectivity.

Application Field

The PFRA.185.3 PTC Resettable Fuse is designed to provide circuit protection against over-current faults. It is commonly used in home automation and consumer electronic devices where current and voltage regulation are critical. These devices are typically used for controlling the temperature, air conditioning, lights, and other low-power control applications. The PFRA.185.3 has an operating temperature range of -40°C up to +85°C and is designed to protect circuits from over-currents up to 2.5A.

Working Principle

The PFRA.185.3 utilizes a Polyfuse, which is a small component that contains an internal element that expands or contracts depending on the amount of current. It operates by the principles of the PTC (Positive Temperature Coefficient) where an increase in temperature causes an increase in resistance. When an over-current occurs, the internal element of the Polyfuse will start to expand and the electrical resistance will increase, thereby limiting the current. Once the current has been reduced to a safe level, the internal element of the Polyfuse will contract and the electrical resistance will decrease, allowing the circuit to operate normally.

The PTC Resettable Fuses provide a number of advantages over the traditional fuse systems. They are relatively easy to install, low cost, and provide robust protection. The PFRA.185.3 is rated for currents up to 2.5A and an operating temperature range of -40°C up to +85°C, making it ideal for a variety of home automation, consumer electronic, and related applications. Additionally, the PFRA.185.3 is designed with low power loss in mind, making it an efficient choice for controlling the temperature and other low-power control applications.

In summary, the PFRA.185.3 PTC Resettable Fuse is an ideal choice for circuit protection against over-currents up to 2.5A. It is designed with low power loss in mind and is rated for operating temperatures of -40°C up to +85°C. The PTC Resettable Fuse provides an easy-to-install, low-cost solution for protecting consumer electronics and other sensitive electronic components.