Abstract: A circuit having a stationary portion and a rotating portion suitable for an arcuate scan assembly in a storage device is disclosed. The circuit includes a stationary encoder outputting an encoded write signal; a power supply; and a rotary transformer comprising a stator and a rotor. The stator has at least one stator winding and the rotor has at least one rotor winding, with the stationary encoder coupled to the stator winding. A decoder is provided and includes an input coupled to said at least one rotor winding and rotating with the rotor. The input receives an encoded write signal, and the decoder further has an output. Also provided is an amplifier coupled to receive the decoder output, and further being coupled to the power supply via the rotating transformer. The amplifier rotates with the decoder and the rotor. Also, at least one read/write head is included and is coupled to receive an amplifier output from the amplifier and return a read data signal to the amplifier.

Abstract: A hard disk drive system operates from a limited power source to provide for the storage of data on the surface of a rotating hard disk media. An embedded controller incorporates a data channel for transferring data with respect to a hard disk media. The controller includes first and second subsections and a power-down circuit for providing separately switchable power from the power source to the first and section subsections. The controller further includes a processor for controlling the power-down circuit. The processor nominally provides a low duty cycle control signal to the power-down circuit for switching the provision of power to the first subsection of the controller.