[AT] [OT] Has anyone seen one of these??

[Steve W.]

Spencer Yost wrote:
> DC grids slowly lost ground in the 1900s, so if the vacuum is really
> that old (1912) then it seems likely to have a universal motor
> designed to run on both.   The DC grid was similar voltage, so 115
> would be right.
> 
> I remember that the last DC grid only came down sometime In the last
> few decades.   I remember because I was incredulous that one existed
> when I read about it - and get this - IN A NEWSPAPER.  Remember
> those? (-;
> 
> Electrical guys in the group are going to have to jump in a fact
> check me on all this.
> 
> Sent from my iPhone
> 

Full DC power grids still exist in some cities today! San Fransisco shut 
their last rectifier grid down in 2011. But Chicago and Boston still 
have DC grids running with AC. It powers a lot of the old infrastructure 
in the oldest buildings. In other cities the DC is generated at the 
buildings needing it.

Other than a very few test locks, all of the locks on the Erie Canal 
still use DC power for the lock motors and lift winches.

-- 
Steve W.