On Thu, 6 Oct 2011 19:07:43 +0000 (UTC) Virgo Pärna <virgo.pa...@mail.ee> wrote:
> On Fri, 7 Oct 2011 02:12:53 +1300, Chris Bannister > <mockingb...@earthlight.co.nz> wrote: > > > > Not sure I understand what you are saying. Unless the wrong terms are > > being used, but transformers "hate" DC. Plus also, think of voltage like > > > > I ment the voltage drop on the long lines. And that there was no device > like > transformer for DC. Thanks the existance of transformers AC could be easily > converted > to higher and lower voltages - shich ment, that long distance transmissions > could be at > high voltage and converted to lower voltage near the consumer. And that was > one of > the main reasons, why AC one out. > Nowadays DC current is actualy used for long distance high voltage power > transmissions > (because of lower losses). But it's my understanding that the voltage > conversion is still > not as easy and simple, as it is with AC. > Very simple, if you switch a DC voltage on and off repeatedly, what wave form do you get ? If the period of switching it on is shorter that the off period the equivalent output voltage is proportional the the width of the pulse chain, ie pulse width modulation. And a much higher efficiency voltage and mode conversion. A much simpler process and less lossy. Only recently possible with high voltage high current due to developments in semiconductor power handling. -- Best wishes / 73 e-mail: rich...@g8jvm.com Richard Bown nil carborundum a illegitemis ################################################################################## Ham Call G8JVM . OS Fedora FC15 x86_64 on a Dual core AMD Athlon 4400, 4 GB RAM Maidenhead QRA: IO82SP38, LAT. 52 39.720' N LONG. 2 28.171 W ( degs mins ) QRV HF + VHF Microwave 23 cms:140W,13 cms:100W,6 cms:10W & 3 cms:5W ################################################################################## -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20111006203323.3d89a...@bigun.g8jvm.com
