> > From: "Digital Image Studio" <[EMAIL PROTECTED]> > Date: 2007/06/21 Thu AM 09:26:09 GMT > To: "Pentax-Discuss Mail List" <pdml@pdml.net> > Subject: Re: Re: Lightroom and organizing files > > On 21/06/07, mike wilson <[EMAIL PROTECTED]> wrote: > > > That would be illegal in the UK. There are very strict requirements laid > > down as to what voltage and cycles (within very small limits, usually > > required to be corrected to absolute values over a 24hour cycle) have to be > > delivered. AFAIR, deviation from a plain sine wave is also not allowed. > > Mains signaling technologies used to invoke off-peak power at the > customers premises and various other control actions on the grid are > pretty wide spread, I assume the UK would use them too. Generally a > voltage of between 2-7 volts is imposed (modulated) on the mains at > audio frequencies. In the case of a local suppliers the frequencies in > use include 158, 167, 183, 206, 217, 225, 270, 283, 297, 317, 390, > 435, 492, 494, 500, 580, 750, 760 and 12500Hz.
Seems to be the case. Interesting, as in the early 1970s I was trying to develop a simple in-home system of using the mains wiring in a house to transmit signals for various purposes. After contacting the local supplier on some technical matters, we received a formal "cease and desist" notice from them, pointing out the regulations I mentioned above. I think we only avoided prosecution because we were under age. ----------------------------------------- Email sent from www.virginmedia.com/email Virus-checked using McAfee(R) Software and scanned for spam -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
