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AEC-Q200 qualified fuses play a critical role in the automotive environment
The protection fuses provide is especially beneficial to the
to sensitive electronics, but not for motors due to the high inrush current at start-up. Slow blow fuses have been developed for this application, where the response time can be in the order of several seconds. Some of the other characteristic requirements for fuses used in automotive applications include: ■ Higher voltages of up to 800 V for the changing bus are expected soon. For this reason, ratings exceeding 1,000 V will be required, with great attention given to the arc discharge created at these voltages to prevent circuit damage. ■ High reliability due to the risk of catastrophic accidents due to failure. ■ Large range of ambient temperature. Fuses used in the engine compartment can face temperatures ranging from -40˚C to +150˚C or wider. ■ Size, weight, and form factor are key minimization goals for all components used in an EV, driven by the need to increase vehicle performance and range for a given battery charge. ■ Vibration resistance is a key requirement due to varied road conditions and driving profiles.
The AEC-Q200 automotive standard Chrysler, Ford, and General Motors established the Automotive Electronics Council (AEC) in the 1990’s to create a common quality system and unify part qualification standards for automotive applications. The AEC-Q200 standard covers the stress test qualification for passive components. The earlier Rev D of AEC-Q200, which has been active since June 2010, covered components such as resistors, capacitors, transformers, resonators, crystals, resettable fuses, thermistors, and varistors. This standard covered two main stress categories for the passive components: ■ Environmental stress: This includes temperature cycling, humidity bias, high temperature storage, and high temperature operating life tests. ■ Physical stress: This includes vibration, mechanical shock, solderability and resistance to soldering heat, flammability, terminal strength, and resistance to solvents.
growing automotive market and the rising demand for electric vehicles (EVs). With EV power conversion and the ever-increasing number of electronic systems, circuit protection has become an imperative to safeguard the myriad of devices present in an EV. Automotive fuses The typical automotive fuse works by melting a conductive link. An electric arc follows, turning the link into an open circuit. The current pulse (magnitude, shape, and time), the ambient temperature, and the characteristics of the fuse determine the temperature within the fuse element at which this occurs. The time-current curve (called TCC) at different rated fuse currents helps determine the interrupt time at a given current. This, along with the melting energy (I 2 x t, where I is the current and t is the time), helps determine a suitable fuse for the application. Automotive fuses have evolved to meet the changing needs of the industry. In the 1960s, glass tube fuses were commonly used. More compact blade fuses are the most used today. Most of these are fast responding (in a few milliseconds), which is good to prevent damage
By Rolf Horn Contributed By DigiKey's European Editors
by interrupting the flow of electric current. This interruption can protect wiring, electronic devices, and the load from catastrophic damage. Therefore, fuses can minimize the fault condition risk of injuries to people and property.
Fuses have been used as essential protective devices since the dawn of electrical lighting in the late nineteenth century. They protect devices from faults such as short-circuits occurring at a load
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