Re: The ohnosecond

I read in sci.electronics.design that Ken Smith <kensmith@xxxxxxxxxxxxxxx> wrote (in <dklu18$ui5$3@xxxxxxxxxxxxxx>) about 'The ohnosecond', on Sun, 6 Nov 2005:
In article <xAHWnfYQOkbDFwop@xxxxxxxxxxxxxxxx>, John Woodgate <noone@xxxxxxx> wrote: 
I read in sci.electronics.design that Ken Smith
<kensmith@xxxxxxxxxxxxxxx> wrote (in <dkldts$f6v$1@xxxxxxxxxxxxxx>)
about 'The ohnosecond', on Sun, 6 Nov 2005:

I know that 7500V/inch is a good rule for long term voltage gradient on
a PCB but I can't find a good reference for a rule for shorter amounts
of time.  Does anyone know of one?


For you, UL standards usually have decided opinions on the matter. For
others, IEC 60950-1, IEC 60065, IEC 60335-1 etc., etc.

I haven't been able to locate anything about 1 minute time frame.

Clause 5.2.2 of IEC 60950-1, for example, requires the hi-pot test to last 60 s, which is about 1 minute. (;-)

You would also need to read bits of the long clause 2.10 and probably Annex G as well.

But having done that you will know more about clearances and voltages than you ever expected.
--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
.