T-Pain Is On A Boat: Re: [Electric Boats] 39 dollar clamp on ebay ammeter.

Monday, August 10, 2009

Re: [Electric Boats] 39 dollar clamp on ebay ammeter.

hI , I've purchased some digital volt and amp gauges from these folks on ebay example: http://cgi.ebay.com/50A-DC-ON-OFF-BLUE-LCD-DIGITAL-PANEL-CURRENT-AMP-METER_W0QQitemZ260446730465QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3ca3d5b8e1&_trksid=p3911.c0.m14 Have volts and amps for motor and house battery banks. i have them mounted on the boat (in the cockpit behind a removable plexi panel) but not yet hooked up . Waiting on my son Nolan, the electrician, to help out. Anybody else tried their gauges? Their shipping was fast, although from Hong kong, not from Ireland as the ebay ad suggests.

Best Regards,

Paul <paul136mc@yahoo.com>

Paul C. Smith 707 874 2112
PO Box 120
Camp meeker, CA 95419

________________________________
From: Matthew Geier <matthew@acfr.usyd.edu.au>
To: electricboats@yahoogroups.com
Sent: Sunday, August 9, 2009 8:56:22 PM
Subject: Re: [Electric Boats] 39 dollar clamp on ebay ammeter.

Hans Kloepfer wrote:
> Thanks George.
>
> I tried some of these types of units, and I burnt them all out. I talked to another guy who had the same bad luck with these types of instruments. Unfortunately, I have to keep them installed so I don't have holes in the custom made instrument panel on my boat. This annoys me. The problem is the power supply. It works fine with a 9 volt battery, but if you want to wire it your boats house power, as in my situation, it creates a short circuit condition.
>
> Anyone else have any input on these things (shunt-wired, ebay variety LCD digital volt/amp meters). I would still like to get something in those holes that actually works.
>
> I would still like a handheld multimeter for analysis/ diagnostics that I could just clamp around a cable to check DC amperage on different legs of the electrical system on the boat. Usually these are pretty expensive. Maybe I will just have to pony up the dough for a nice Fluke or similar.
>
A 'clamp' DC ammeter is a far more complex beast than a clamp AC ammeter.

The AC ones effectively make a one turn transformer and measure the
induced voltage. This doesn't work on DC. I think they measure the
magnetic field or something like that.
It's quite common to have a DC amp function on a AC/DC clamp meter
where the only the AC amps is via the 'clamp probe'. DC current
measurements require breaking the circuit.

A too-cheap AC/DC clamp meter may only measure AC current via the
clamp. Read the specs carefully. :-)

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