Resettable fuses, also known as Polymeric Positive Temperature Coefficient (PPTC) devices, are electronic components that protect circuits from overcurrents and short circuits. Unlike traditional fuses that need to be replaced after they are blown, resettable fuses automatically reset themselves after the fault condition is removed. This makes them a cost-effective and reliable solution for applications where frequent power surges or voltage spikes are expected. Resettable fuses are used in a variety of electronic devices, such as power supplies, computer peripherals, and automotive systems, to ensure safe and uninterrupted operation. In this article, we will explore the working principle, types, applications, and benefits of resettable fuses.