Variable Voltage HDD Signal Circuitry for Power Reduction
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Solution Overview
Problem
Conventional hard disk drives (HDDs) consume relatively high power due to their moving parts, leading to short battery life in portable systems and negative performance and reliability consequences when power-saving methods are implemented.
Innovation Solution
The HDD design varies the supply voltage to circuitry based on changes in data transfer rate as different regions of the storage disk are accessed, using lookup tables to set the supply voltage to allow digital signal processing circuitry to operate at frequencies equal to or slightly higher than the current data transfer rate, thereby reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the supply voltage to signal processing circuitry is held at a constant high value, then the circuitry can operate at maximum performance, but power consumption increases
Solution Approach 1:
The patent applies dynamics by making the supply voltage variable rather than constant. The voltage supplied to the signal processing circuitry is dynamically adjusted based on the current data transfer rate requirements. When the read/write head accesses different regions of the storage disk requiring different data transfer rates, the supply voltage is modified accordingly to match the actual performance needs, avoiding unnecessary power consumption at maximum voltage when full performance is not required.
Solution Approach 2:
The patent changes the electrical parameter (supply voltage) of the signal processing circuitry based on operating conditions. By monitoring the current data transfer rate and adjusting the supply voltage parameter accordingly, the system optimizes the balance between performance and power consumption. The voltage is increased when higher data transfer rates are needed and decreased when lower rates suffice, directly addressing the contradiction between productivity and energy use.
2Use of energy by moving object
If the supply voltage is reduced to save power, then power consumption decreases, but the circuitry may not operate at required frequencies
Solution Approach 1:
The patent implements feedback by continuously monitoring the current data transfer rate and using this information to adjust the supply voltage. The system has a feedback loop that detects when the read/write head accesses different regions of the storage disk and modifies the voltage accordingly. This ensures the circuitry operates at the minimum necessary frequency for the current data transfer rate while consuming optimal power, preventing both over-voltage power waste and under-voltage performance degradation.
Data Source
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AI summary
A data storage drive comprises a storage disk, a read/write head, and signal processing circuitry in signal communication with the read/write head. The read/write head is operative to read data from and write data to the storage disk at a plurality of data transfer rates. Moreover, the signal processing circuitry is powered by a variable power source. The variable power source vanes supply voltage to the signal processing circuitry as a function of a current one of the data transfer rates of the read/wpte head. Power consumption is reduced in this manner.