US Patent 8982502 Hard disk drive with write assist based on detected conditions

In one embodiment, a hard disk drive includes a magnetic disk medium, a magnetic head adapted for writing data to the magnetic disk medium, a mechanism (such as a detection circuit) adapted for detecting at least one recording condition of drive current provided to the magnetic head during writing operations, and an energy conversion element for controlling at least one recording characteristic of the magnetic head in response to the at least one detected recording condition. According to another embodiment, a method includes writing data to a magnetic medium using a magnetic head, detecting at least one recording condition of drive current provided to the magnetic head during the writing, and controlling at least one recording characteristic of the magnetic head during the writing using an energy conversion element in response to the at least one detected recording condition.