What is the role of the thermal sensor on a hard drive PCB?

The thermal sensor on a hard drive PCB is used to monitor the temperature of the hard drive. The thermal sensor is typically located near the spindle motor or the read/write heads of the hard drive, as these components generate heat during operation. The thermal sensor sends temperature readings to the hard drive's firmware, which can then adjust the operation of the hard drive to maintain safe temperature levels. The thermal sensor is an essential component for the performance and longevity of the hard drive, as it helps to prevent overheating and damage to the internal components.