Thermal fuses break 55A in automotive circuits

June 21, 2013 // By Graham Prophet
Vishay Intertechnology has introduced thermal fuses that offer high current capabilities up to 55A and operation at temperatures up to +160°C for 1,000 hours without unexpected breakdown. AEC-Q200-tested, devices in the new Vishay Beyschlag HCTF series provide a safety interrupt of electrical power in high-current automotive applications.

In the case of excess heat in the range of the functioning temperature of +235°C (± 15 K), HCTF thermal fuses open automatically and disconnect the circuit. Typical applications for HCTF devices include automotive power electronics that can be connected to steady battery power (B+ or terminal number 30), such as control units of fans and pumps for liquid engine cooling, inlet air control units, diesel pre-heaters, engine control units, ABS control units, and Diesel heater plug relays.

The thermal fuses offer significantly higher current capabilities than other devices on the market, which are limited to 25A at an ambient temperature of 23°C or 12A at an ambient temperature of 100°C. The HCTF devices' solid-state design, in combination with low cold resistance of ≤ 0.1 mΩ, guarantees extended reliability at high current loads and ambient temperatures.

Devices in the HCTF series are RoHS-compliant and offer a rated voltage of 24 V. HCTF 235 fuses can be assembled with electric resistance welding while HCTF 235 CP devices can be inserted into clamp terminations. In either case, both versions can be assembled with crimping units.

Vishay Beyschlag, www.vishay.com