No need to worry. First, a CD can be spun at many tens of thousands of RPM without destruction. But more importantly, the spin ratios are not straight multiples of the basic disk RPM. After all, if this were true, the 300 to 400 RPM maximum speed of a 1X CD player, would be 19,000 to 25,600 RPM, and 64X CD-ROMs do NOT rotate that fast.
Much of the increase a 64X CD-ROM is claiming, is due to reading ahead and buffering, so that in normal intermittent use, the apparent transfer rate is (supposedly) 64X normal. This is why tests show that, when large amounts of data are being read, these drives cannot get anything close to their claimed data transfer rate. This is why one cannot read an entire audio CD into memory as a raw WAVE file, at anything close to the claimed rate. Bob Wilson TIR Systems Ltd. Vancouver. -----Original Message----- From: Doug McKean [mailto:dmck...@corp.auspex.com] Sent: May 9, 2002 3:34 PM To: EMC-PSTC Discussion Group Subject: A little off topic but ... exploding CD's ??? As a matter of safety, has anyone really addressed the issue of the upper speed limit of CDs? Quoted from the following webpage ... http://www.qedata.se/e_js_n-cdrom.htm "Introduction But where's the limit? Manufacturers try to outspin each other all the time by selling CD-ROM drives with higher and higher spin ratios. Spin ratios of 2x, 4x, 8x, 16x, 32x, 56x and 64x come in a never ending stream. The CD is forced to rotate faster and faster. At what speed will a CD blow up, and can you do something to prevent it from exploding? ..." At the conclusion of the test, the author recommends the following ... "Safety Recommendations The committee wishes, after finishing its work, to suggest the following safety precautions. Safe distance to a CD-ROM drive with spin ratio 64x CLV should be no less than 5 metres (15 ft.). All work with CD-ROM units should require safety goggles and protective clothing be worn. CD-ROM drives of the 64x CLV class and higher, should be provided with shrapnel protection of no less than 3 mm aluminium or 1 mm steel. To avoid operator inhalation of CD-ROM particles, CD-ROM drives should be provided with a dust suction fan with suitable filter, or have the fan duct connected directly to the outside air. In addition to the laser light warning label, CD drives should be affixed with another label warning against the hazard of shrapnel, such as the one below: " With appropriate labels for exploding CDs. No. This isn't a joke. Regards, Doug McKean ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
