摘要 |
A fan rotational speed control system is operable to control at least a fan and includes a baseboard management controller (BMC), a complex programmable logic device (CPLD), and a switching circuit. The BMC is operable to output a fan pulse wave signal and a Heart bit. The CPLD is operable to receive the Heart bit and determine whether the BMC is abnormal based on the Heart bit. The CPLD is operable to generate and output a switching signal and a take-over pulse wave signal when the BMC is abnormal. The switching circuit is operable to receive and output the fan pulse wave signal when the BMC is normal, and the switching circuit is operable to receive the switching signal and the take-over pulse wave signal to output the take-over pulse wave signal when the BMC is abnormal. |