Re: A little off topic but ... exploding CD's ???

2002-05-10 Thread Douglas_Beckwith
Sounds to me like someone has too much time on their hands. On the face of it, it is amusing, but it is this kind perceived "hazard" that safety agencies and lawyers love, with the result that ridiculous requirements like this start appearing in safety standards. Maybe we should just ban all elec

RE: A little off topic but ... exploding CD's ???

2002-05-10 Thread Gregg Kervill
I have design speed and phase controllers for small systems running at 64 krpm (IR scanner) that used low pressure Helium to reduce drag and to operate 'air' bearings. Some of the big problems in cars are going up-hill and running into ditches (gyroscopic effects) and what happen to that energy

RE: Virus Alert

2002-05-10 Thread John Lach
RE: Virus Alert 5/10/02 I have seen this hoax before do not delete this file or windows will not run. Steve Grobe wrote: > >This could very well be a hoax. > >http://www.sophos.com/virusinfo/hoaxes/sulfnbk.html > > > >> -Original Message-

RE: Virus Alert

2002-05-10 Thread djumbdenstock
This hoax was passed around my area 6 months ago. The "virus" is a self-inflicted virus, i.e., doing what the email suggests damages a necessary part of your file manager program. See the link below for full details. > -- > From: Steve Grobe[SMTP:ste...@transition.com] > Reply T

RE: Constant for Change of Resistance formula.

2002-05-10 Thread Robert Wilson
What are the units? 234.5 ...what?? Looking at what the units are, will basically tell you exactly what the property is related to. Nonetheless, you cannot possibly directly determine what the temperature change of something as physically and geometrically complex as a connector, merely by factor

Re: Constant for Change of Resistance formula.

2002-05-10 Thread Robert Macy
Ned, Not familiar with this K term. For straight resitance changes in transformers, we always used 0.0039 per C. Does K somehow include contact resistance, not just bulk resistance? This is definitely the time to measure it. Environmental chamber at -50, 0, 50, 100, and 150. Make your own cu

RE: A little off topic but ... exploding CD's ???

2002-05-10 Thread Robert Wilson
Going around corners presents another interesting problem, depending on the orientation of its axis. The vacuum chamber that such a flywheel must operate in (to make it practical) presents another interesting challenge. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Chri

RE: Virus Alert

2002-05-10 Thread Steve Grobe
This could very well be a hoax. http://www.sophos.com/virusinfo/hoaxes/sulfnbk.html > -Original Message- > From: Dan Teninty - DTEC Associates > [mailto:dteni...@dtec-associates.com] > Sent: Friday, May 10, 2002 9:52 AM > To: dteni...@dtec-associates.com > Subject: FW: Virus Alert >

Constant for Change of Resistance formula.

2002-05-10 Thread Ned Devine
Hi, Does any one know how the constant for CoR formula was determined? I know the K is 234.5 for copper and 226 for aluminum, but what property is this related to? I am trying to determine the change in temperature of a connector, based on the change of resistance. The connector contacts ar

Govt. launches cell phone site

2002-05-10 Thread rbusche
Attached is a link to MSNBC's news site. There is an article about a new site launched by the FCC and FDA which addresses safety and EMI concerns for cell phones. Thought you might be interested. http://news.com.com/2100-1033-908671.html?legacy=cnet&tag=pt.msnbc.feed..ne_9874454 --

RE: A little off topic but ... exploding CD's ???

2002-05-10 Thread Chris Maxwell
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 bette

Creepage/clearance in EN 61010-1

2002-05-10 Thread Kim Boll Jensen
Hi all I have problems concerning clearance and creepage values in EN61010-1. I have a product with a 24 ac and a 230 relay. The 24ac can be used for sensors and are regarded as double insulated in the 230 Vac transformer for safe operation. But what are the clearance and creepage to the 230 Vac

RE: A little off topic but ... exploding CD's ???

2002-05-10 Thread Robert Wilson
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, a

RE: A little off topic but ... exploding CD's ???

2002-05-10 Thread Summers, Chet
Reminds me of an article I read some years ago, where an engineer was reminiscing about the early days of hard disk drive development. IBM was the company, I think. Anyway, when the "absolutely beautiful and impressive" testbed was fired up and began to run, the nearly room-sized piece of equipm