Homebrew PCBs

Google is cool!  I am going to have to experiment more with that 
function of it.  




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> On Fri, 01 Sep 2006 00:18:05 +0200, herby1620 <herby1620@...> 
wrote:
> 
> > Thickness in um =
> >     0.5 * 10000           454
> > ---------------------- * ---- = 17 um
> > 2.54 * 2.54 * 16 * 144   8.94
> > Some of the numbers used (for reference):
> > 0.5 = ounces/sq-foot (amount of copper)
> > 10000 = um/cm (microns per cm)
> > 2.54 = cm/inch
> > 16 = ounces/pound
> > 144 = square inches/square foot
> 
> 
> 
> I certainly know _why_ i love the SI! That's just frightening...
> 
> I certainly also love google - enter the following line as a 
search term:
> 
> 8920kg/m^3*1ft^2*35micrometer in oz
> 
> and you get
> 
> 1.0230976 ounces
> 
> The good thing about google calculator is it can deal with units 
and do  
> the conversions for you. And if you have a mistake in the formula, 
like  
> divide somewhere instead of multiplying, the result will just not 
come out  
> in the correct unit. If i do that on paper i need to engage brain 
to check  
> that....
> Sadly it does not (yet) know the density of copper automatically 
it seems.
> 
> 
> ST
>