[Boatanchors] Long-term AC voltage monitor

[Richard Knoppow]

    I think what you want is a recording voltmeter.  I don't 
know one that is ready made but I think it should be 
possible to adapt any that have digital output so that a 
small computer program could record the voltage as a 
periodic chart or as a continuous graph.  The old method of 
course is to use a chart recorder but I think any computer 
should be able to do this.  It would be interesting to know 
how much the mains voltage varied and when.
    I have measured the voltage in my shack. During the 
summer it went from around 125V to 108 volts probably 
depending on the air conditioner load in the neighborhood.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com
----- Original Message ----- 
From: "Rick Poole WA1RKT" <wa1rkt at comcast.net>
To: <boatanchors at mailman.qth.net>
Sent: Monday, January 05, 2015 7:32 AM
Subject: [Boatanchors] Long-term AC voltage monitor


> 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...
>
> Rick WA1RKT
> Londonderry, NH
> Catch me on 14.300 MHz Intercon / MMSN most days
>    also occasionally on 7.255 ECARS