Household electrical current to Excel ???

Here is a UK source for a multi-meter with an RS-232 port and data logging software:

price (£96) is rather more than the similar items seen by Pete C though.

Much more attractive price!

Have you tried it? Does it pump out readings periodically or on demand? Is the protocol documented so you can write your own software?

The one thing I ran into, is a lot of their products are surface mount.

But I was able to 'SuperGlue' a 1/8 dowel underneath the 8 pin package and then solder some hairline strands to the legs. Ran the strands to some more conventional 22AWG, and wrapped the whole thing up in a layer of tape. Gives me a nice 'probe' about 3/16" diameter that I can poke into furnace ducts, strap onto hot-water pipe (with some foam pipe insulation around probe to help improve accuracy) or whereever. Even drilled small hole in sill-plate and stuck one through to get an 'outdoor' reading.

Although two of the units failed early because of my... (ahem...) soldering skill with SO packages (well, afterall I was using a 15w pencil iron to do SO, so what can you expect). But once I got things down pat, I've gotten 12 working units.

Had some old cat-5 scraps, and there was already a couple of cat-5 runs up to the attic area. Made for good wire to connect them all together. So now I have a linux box sitting in the basement 'logging' temperatures from all around the attic, basement, furnace.

Got some of their straight A/D converters from another hobby source. These came with the surface mount chip already mounted in a standard 8-pin dip plug. They only take 0-5V input, so I've been tinkering with some 'signal conditioner' circuits to attach a solar cell for measuring potential 'sun input' for different placements around the place.

Just a hobby, but interesting, keeps me off the streets. And my wife doesn't mind as long as there's no wires strung across the kitchen table ;-)

daestrom

You might be quite interested by this:

Which is what I have used for a similar reason to yours!

By fitting the sensor into a standard utp connector, wired to some of the "spare" cores, you can just plug them in where you fancy, moving them when you want, and connect out at the patch panel.

-- Sue

Dave, That is a great device. It seems is very simple to use and install and has many "Predictable" functions such as what will the next electricity bill amount to. It seems like there is a European or non-U.S. version. This is wahat they say on the website...

The Electric Usage Monitor installs easily on the electric breaker panel (110/220V) box. Users simply install the unit, set the rate and press the reset button to start measuring electric consumption in kilowatt hours (kWh).

The Electric Usage Monitor is purchased primarily by homeowners, renters and apartment owners and by U.S. utility companies, electrical contractors, air conditioner contractors, and energy professionals. An international version also exists for clients outside of the U.S.

Declan

I wouldn't advocate using it with a shunt, but it ought to be easy enough to add a current transformer. To wind your own, determine the needed full-scale secondary voltage -- it will be millivolts at most -- and figure .25V/turn/in^2 of core. Make the turns ratio whatever you need. You can assemble the core around the mains conductor is a single primary turn will do (and it should).

Jerry

If you have access to surplus Radio Frequency meters of the type used on broadcast stations ( transmitter's site) and you can break your power line to insert a meter, open the meter's case and attach a couple of wires to the internal meter connections, after the thermocouple. The meter will display the r.m.s. current and will give you a dc connection to the outside Connect the 2 wires to a voltmeter with a serial output and you can display all the information you need and/or use excel for further manipulation.

Those meters are very precise and usually available from surplus places.

Advantages are that they measure r.m.s current, disadvantages are that they are very sensitive to overload. You apply twice the maximum current and the thermocouple is finished.

Vlad

Let me clarify some thing. The meters are very precise because the scale is printed to conform to the actual current. The dc output will not be linear . You may use excel to give you the same reading as the meter's scale.

Vlad

Here's a very interesting product capable of data logging and 220 VAC @50 hz and is cheap too. However it seems like it is designed to monitor one appliance only rather than Whole House.

Declan

"daestrom" wrote in news:Oi4Re.53387 $ snipped-for-privacy@twister.nyroc.rr.com:

There are a variety of products that break SMT products into something easier to prototype. One produce is at

I think you are right Dave. The link you gave (

) certainly does the business for a few dollars extra. Approx $200 It comes with split coils for an extra few dollars meaning the wiring does not have to be undone to get the coils on as the coils themselves split and can be re-assembled on the wiring.

Declan