[Boatanchors] Long-term AC voltage monitor

[Jim Wilhite]

You are correct about boatanchors designed in the 30s and 40s then it was 
upped in the 50s, however later equipment was designed for 120 VAC and 
should be fine on todays mains.  My Globe King 500A, designed in the early 
50s is specified for 115 volts +/- 10% @ 50-60 cycles.  Later, equipment 
manufacturers upped the voltage to 120 in the 60s.  I run all my equipment 
connected directly to the mains without trouble @125 Volts.  The mains 
voltage is specified +/- 10% so if you have equipment for 115 then it is 
designed to accept mains voltage from 103 to 127.  Yes 125 is the upper 
range but your equipment, if the components are in good condition, should 
not notice it.

If you have a UPS system on your computer it will monitor your mains voltage 
for you, no need to purchase anything else.  I have a Tripplite on mine 
presently and it has a downloadable software console that I can access on my 
computer to see the mains voltage.  In the past I  have used APC and they 
have the same type of thing.  If necessary, purchase an inexpensive AC 
voltmeter at Harbor Freight and replace the leads with a cheater cord made 
with banana plugs for the input.  Just be careful with that.

The only caveat, if you use the UPS on console, is you must have a UPS that 
is connected to your computer either through wireless network or by a USB 
port and download the software.

Jim
W5JO


-----Original Message----- 


Most boat anchors, it seems, were designed for an AC input voltage of 
nominally 110-115VAC.  These days voltages are more like 120-125, from most 
reports, so folks are recommending a bucking transformer or variac in the AC 
line.

I'm looking for a CHEAP (sorry, gotta be cheap) AC monitoring device, such 
as a USB voltmeter that stores its readings periodically on a computer, that 
I can use to monitor AC mains voltage around here and see if I have a 
problem.  I periodically stick a multimeter into the AC socket and rarely 
see anything above 120 (last I looked it was 118.2) but that only tells me 
what the voltage is when I'm looking, doesn't tell me about any other time.

Something that plugs into a USB port, with software to periodically store 
the results, would work, but Google hasn't been much help in finding one of 
those.  The Yoctopuch Yocto-Volt from Switzerland will do it but the US 
distributer is out of stock with no indication when or if they will ever 
have any more.  I can order from Switzerland if I absolutely must but 
something that's available in the US would be better.  There's also the 
Electronics-DIY USB Voltmeter but there is nothing that indicates that works 
on AC (it looks like the input goes directly into a PIC device through a 
voltage divider so it's tough to imagine it working on AC).

Any suggestions?  Thanks...