I hope that I don't lead the thread off on a tangent...but a similar problem is being encountered by those who envision magnetically levitated flywheel powered electric cars. (By the way, the flywheel is levitated, not the car)
A well designed flywheel system can store electricity with a better weight to energy ratio of currently available batteries...But. In order to do so with a lightweight flywheel (about 50 pounds); the flywheel needs to spin up to something like 100,000 rpm. They are testing composite materials (graphite, kevlar...) and the testing has led to some spectacular failures with shredded flywheel all over the place. The other problem is...how do you contain these babies if the car has an accident. Just imagine a wreck that produces a bunch of 50lb buzz saws bouncing around the intersection...it wouldn't be pretty. As far as CD's...maybe everyone should just listen to George Jones... or something else that is slow enough to keep he speed safe :-) Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -----Original Message----- > From: Doug McKean [SMTP:dmck...@corp.auspex.com] > Sent: Thursday, May 09, 2002 6:34 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"
