V HELP

 

LET'S TOGETHER HELP THE PEOPLE IN NEED

LET'S TOGETHER CHANGE OUR SOCIETY

VHELP

 

JOIN NOW

 

V TEACH

 

 

 

 

 

 

 

 

Copyrights 2008-09 VHELP TEAM All Rights Reserved

Variable definitions ==================== */ /* Use this with templates/template-twocol.html */ body { background:#ffffff; margin:0; color:#333333; font:x-small Georgia Serif; font-size/* */:/**/small; font-size: /**/small; text-align: center; } a:link { color:#5588aa; text-decoration:none; } a:visited { color:#999999; text-decoration:none; } a:hover { color:#cc6600; text-decoration:underline; } a img { border-width:0; } /* Header ----------------------------------------------- */ #header-wrapper { width:660px; margin:0 auto 10px; border:1px solid #cccccc; } #header-inner { background-position: center; margin-left: auto; margin-right: auto; } #header { margin: 5px; border: 1px solid #cccccc; text-align: center; color:#666666; } #header h1 { margin:5px 5px 0; padding:15px 20px .25em; line-height:1.2em; text-transform:uppercase; letter-spacing:.2em; font: normal normal 200% Georgia, Serif; } #header a { color:#666666; text-decoration:none; } #header a:hover { color:#666666; } #header .description { margin:0 5px 5px; padding:0 20px 15px; max-width:700px; text-transform:uppercase; letter-spacing:.2em; line-height: 1.4em; font: normal normal 78% 'Trebuchet MS', Trebuchet, Arial, Verdana, Sans-serif; color: #999999; } #header img { margin-left: auto; margin-right: auto; } /* Outer-Wrapper ----------------------------------------------- */ #outer-wrapper { width: 660px; margin:0 auto; padding:10px; text-align:left; font: normal normal 100% Georgia, Serif; } #main-wrapper { width: 410px; float: left; word-wrap: break-word; /* fix for long text breaking sidebar float in IE */ overflow: hidden; /* fix for long non-text content breaking IE sidebar float */ } #sidebar-wrapper { width: 220px; float: right; word-wrap: break-word; /* fix for long text breaking sidebar float in IE */ overflow: hidden; /* fix for long non-text content breaking IE sidebar float */ } /* Headings ----------------------------------------------- */ h2 { margin:1.5em 0 .75em; font:normal normal 78% 'Trebuchet MS',Trebuchet,Arial,Verdana,Sans-serif; line-height: 1.4em; text-transform:uppercase; letter-spacing:.2em; color:#999999; } /* Posts ----------------------------------------------- */ h2.date-header { margin:1.5em 0 .5em; } .post { margin:.5em 0 1.5em; border-bottom:1px dotted #cccccc; padding-bottom:1.5em; } .post h3 { margin:.25em 0 0; padding:0 0 4px; font-size:140%; font-weight:normal; line-height:1.4em; color:#cc6600; } .post h3 a, .post h3 a:visited, .post h3 strong { display:block; text-decoration:none; color:#cc6600; font-weight:normal; } .post h3 strong, .post h3 a:hover { color:#333333; } .post-body { margin:0 0 .75em; line-height:1.6em; } .post-body blockquote { line-height:1.3em; } .post-footer { margin: .75em 0; color:#999999; text-transform:uppercase; letter-spacing:.1em; font: normal normal 78% 'Trebuchet MS', Trebuchet, Arial, Verdana, Sans-serif; line-height: 1.4em; } .comment-link { margin-left:.6em; } .post img { padding:4px; border:1px solid #cccccc; } .post blockquote { margin:1em 20px; } .post blockquote p { margin:.75em 0; } /* Comments ----------------------------------------------- */ #comments h4 { margin:1em 0; font-weight: bold; line-height: 1.4em; text-transform:uppercase; letter-spacing:.2em; color: #999999; } #comments-block { margin:1em 0 1.5em; line-height:1.6em; } #comments-block .comment-author { margin:.5em 0; } #comments-block .comment-body { margin:.25em 0 0; } #comments-block .comment-footer { margin:-.25em 0 2em; line-height: 1.4em; text-transform:uppercase; letter-spacing:.1em; } #comments-block .comment-body p { margin:0 0 .75em; } .deleted-comment { font-style:italic; color:gray; } #blog-pager-newer-link { float: left; } #blog-pager-older-link { float: right; } #blog-pager { text-align: center; } .feed-links { clear: both; line-height: 2.5em; } /* Sidebar Content ----------------------------------------------- */ .sidebar { color: #666666; line-height: 1.5em; } .sidebar ul { list-style:none; margin:0 0 0; padding:0 0 0; } .sidebar li { margin:0; padding-top:0; padding-right:0; padding-bottom:.25em; padding-left:15px; text-indent:-15px; line-height:1.5em; } .sidebar .widget, .main .widget { border-bottom:1px dotted #cccccc; margin:0 0 1.5em; padding:0 0 1.5em; } .main .Blog { border-bottom-width: 0; } /* Profile ----------------------------------------------- */ .profile-img { float: left; margin-top: 0; margin-right: 5px; margin-bottom: 5px; margin-left: 0; padding: 4px; border: 1px solid #cccccc; } .profile-data { margin:0; text-transform:uppercase; letter-spacing:.1em; font: normal normal 78% 'Trebuchet MS', Trebuchet, Arial, Verdana, Sans-serif; color: #999999; font-weight: bold; line-height: 1.6em; } .profile-datablock { margin:.5em 0 .5em; } .profile-textblock { margin: 0.5em 0; line-height: 1.6em; } .profile-link { font: normal normal 78% 'Trebuchet MS', Trebuchet, Arial, Verdana, Sans-serif; text-transform: uppercase; letter-spacing: .1em; } /* Footer ----------------------------------------------- */ #footer { width:660px; clear:both; margin:0 auto; padding-top:15px; line-height: 1.6em; text-transform:uppercase; letter-spacing:.1em; text-align: center; } -->

Friday, September 3, 2010

USB speakers set to get more out of laptops


Soon, music aficionados can use plug-in USB speakers that produce high-quality sound from the laptop without the need for mains power.

The tinny fizz produced by most laptops’ built-in speakers spoils the music quality because the USB port, from which they get their power, can supply only 2.5 watts. Now, the British firm NXT of Cambourne, Cambridgeshire, has come up with a USB-powered system that can deliver up to 15 watts to each speaker, reports New Scientist.

Although power from mains-powered units is held at around 32 volts, a USB 2.0 port can deliver no more than 5.25 volts to a device.

NXT chief executive James Lewis says that most of the time music is quiet enough to be reproduced satisfactorily by circuits running at just 1 volt. So NXT built its USB-powered amplifier to run at low voltage, but able to deliver higher voltages - and more power to the speakers.

This is done by tapping a pair of capacitors that store spare power from the USB during quiet passages. By pre-determining the music signal a couple of milliseconds ahead of the amplifier, the system determines exactly when to raise the voltage and unleash the stored power.

“It’s the first time I’ve heard of using the dynamic reallocation of power for this type of application. It seems like a great idea,” said Andy Dowell, a director of Dolby Laboratories in the U.K. “People would love to get more oomph out of the PC speakers.”

Posted by at
Labels: , ,

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)