Thursday, 31 July 2008

Novel power saving in electronics

Much is written about the power consumption of today's consumer electronics.  New battery technology is one approach to reducing the consumption of portable devices.  Alternatives to batteries such as fuel cells are another approach.  But the third way that I normally answer this question for the future with is to use less power by being smart, particularly in software.  

An audio equipment company has now implemented this approach in a headphone amplifier.  First they have used a trick in the hardware to halve the supply voltage used resulting in half the power consumption.  They dynamically alter the supply voltage by tracking the signal output so that efficiency is improved.  The supply is generated by a two level charge pump.  The pump is programmed a few milliseconds ahead of the time that the signal arrives in order to avoid distortion and noise.  A carefully developed algorithm is responsible for programming the correct characteristics.  The algorithm had to be 'trained' by experimenting with a wide range of music genres.  

This approach shows an excellent example of how software can provide the intelligence for something that you might otherwise assume is fixed by the hardware, while addressing the never-ending power problem. 

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