<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Apr 10, 2010, at 3:23 AM, Trevor Brown wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div lang="EN-US" link="blue" vlink="purple" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div class="Section1"><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">I would like to say that 405/25 and 625/25 in the UK was forward thinking<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Ie 24 FPS films could be played at 25FPS and nobody would notice,<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">but it was because of the mains frequency and if you locked to it picture hum would not move<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">I don’t know why the mains was 50hz, I don’t think we planned it that way in anticipation of television coming <o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">but you have to win one now and again.<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "><o:p> </o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Trevor<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">UK Member<o:p></o:p></span></div><div style="margin-top: 0cm; margin-right: 0cm; margin-bottom: 0.0001pt; margin-left: 0cm; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> </span></div></div></div></span></blockquote></div><div><br></div><div><br></div><div>The reason why we have incompatible AC power frequencies is this:</div><div><a href="http://en.wikipedia.org/wiki/Utility_frequency">http://en.wikipedia.org/wiki/Utility_frequency</a></div><div><br></div><div><font class="Apple-style-span" face="sans-serif" size="3"><span class="Apple-style-span" style="font-size: 13px; line-height: 19px;"><span class="Apple-style-span" style="font-size: 17px; font-weight: bold; "><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">Though many theories exist, and quite a few entertaining urban legends, there is little certitude in the details of the history of 60 Hz vs. 50 Hz.</span></font></div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">The </span></font><a href="http://en.wikipedia.org/wiki/Germany" title="Germany" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">German</span></font></a><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;"> company </span></font><a href="http://en.wikipedia.org/wiki/AEG" title="AEG" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">AEG</span></font></a><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;"> (descended from a company founded by Edison in Germany) built the first German generating facility to run at 50 Hz, allegedly because 60 was not a </span></font><a href="http://en.wikipedia.org/wiki/Preferred_number" title="Preferred number" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">preferred number</span></font></a><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">. AEG's choice of 50 Hz is thought by some to relate to a more "metric-friendly" number than 60. At the time, AEG had a virtual </span></font><a href="http://en.wikipedia.org/wiki/Monopoly" title="Monopoly" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">monopoly</span></font></a><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;"> and their standard spread to the rest of Europe. After observing flicker of lamps operated by the 40 Hz power transmitted by the </span></font><a href="http://en.wikipedia.org/wiki/International_Electro-Technical_Exhibition_-_1891" title="International Electro-Technical Exhibition - 1891" class="mw-redirect" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; background-position: initial initial; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">Lauffen-Frankfurt link</span></font></a><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;"> in 1891, AEG raised their standard frequency to 50 Hz in 1891.</span></font><sup id="cite_ref-4" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Utility_frequency#cite_note-4" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span><font class="Apple-style-span" face="Helvetica"><span class="Apple-style-span" style="font-weight: normal;">[</span></font></span><font class="Apple-style-span" face="Helvetica"><span class="Apple-style-span" style="font-weight: normal;">5</span></font><span><font class="Apple-style-span" face="Helvetica"><span class="Apple-style-span" style="font-weight: normal;">]</span></font></span></a></sup></div><div style="margin-top: 0.4em; margin-right: 0px; margin-bottom: 0.5em; margin-left: 0px; line-height: 1.5em; "><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;">Westinghouse Electric decided to standardize on a lower frequency to permit operation of both electric lighting and induction motors on the same generating system. Although 50 Hz was suitable for both, in 1890 Westinghouse considered that existing arc-lighting equipment operated slightly better on 60 Hz, and so that frequency was chosen.</span></font><sup id="cite_ref-5" class="reference" style="line-height: 1em; "><a href="http://en.wikipedia.org/wiki/Utility_frequency#cite_note-5" style="text-decoration: none; color: rgb(0, 43, 184); background-image: none; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: initial; white-space: nowrap; background-position: initial initial; "><span><font class="Apple-style-span" face="Helvetica"><span class="Apple-style-span" style="font-weight: normal;">[</span></font></span><font class="Apple-style-span" face="Helvetica"><span class="Apple-style-span" style="font-weight: normal;">6</span></font><span><font class="Apple-style-span" face="Helvetica"><span class="Apple-style-span" style="font-weight: normal;">]</span></font></span></a></sup><font class="Apple-style-span" face="Helvetica" size="4"><span class="Apple-style-span" style="font-size: 14px; font-weight: normal;"> Frequencies much below 50 Hz gave noticeable flicker of arc or incandescent lighting. The operation of Tesla's induction motor required a lower frequency than the 133 Hz common for lighting systems in 1890. In 1893 General Electric Corporation, which was affiliated with AEG in Germany, built a generating project at Mill Creek, California using 50 Hz, but changed to 60 Hz a year later to maintain market share with the Westinghouse standard.</span></font></div></span></span></font></div><br><div><div><br></div></div><br><br><div> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Ted Langdell</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Secretary</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" color="#0018ea" style="font: normal normal normal 12px/normal Helvetica; color: rgb(0, 24, 234); "></font></div></div></div></span> </div><br></body></html>