energy monitors

[Spamlet]

But is CSV what you want in any case? Changing it into useful spread sheets and graphs would be a major job in itself for anyone not already set up to handle the processing.

S

[alexander.keys1]

You can get a 'check meter' from electrical wholesalers, I also saw one on TLC's website recently, theirs was about =A312. You will need to mount it on a suitable board or box, with appropriate sockets or other accessories for the appliances you want to measure. This will be a lot more accurate than any of the digital gizmo's, for a start it measures true kWh, not just the amps, and it works down to very low wattages. Also it avoids all the bother with software etc, you just write down the reading at appropriate times.

[chris French]

In message , Fred writes

No. if you get the USB connect module as well then that records the data on the PC it is connected to (whilst it is on).

[Dave Liquorice]

A spreadsheet that can't import a .csv is not with the disc space it is occupying. Comma Seperated Variables is about the lowest common demominator you can have.

Import the CSV to a sheet highlight the bits you want as a graph (chart...) and select the type of graph you want. Can't get much simpler. A lot easier than dealing with XML...

[Spamlet]

--

With respect, spreadsheets are a mystery in themselves to a great many people. Many would not even know what csv means. And they can be very troublesome. For example, I wanted to turn my Outlook Express address book into a database file proper, but I had used shift enter to make line breaks and this was interpreted as a new record for each break. There are many such pitfalls, especially as most people use the enter button (para) instead of proper line breaks. Rarely have I been able to use csv without doing a lot of editing of extraneous commas before all the fields would end up in the right place. Many people would find this baffling. (In fact it has been this that has plagued those wishing to make address labels - as per an earlier question - more than the layout and printing of the labels themselves.) And yes, it would still be easier than learning xml, sql etc.

S

[Theo Markettos]

Hmmm... I wonder how feasible it would be to make a cheap USB transducer? I have a Linux router with USB port sitting next to the electricity meter.

Perhaps a cheap USB soundcard ($3 on DX) or 'Skype phone' and a coil around the meter tails, plus a quick software FFT to measure the power of the 50Hz harmonic? I wonder how well calibrated that might be? Is there an audio level for 'line in' or 'microphone' inputs?

Theo

[Geo]

You can buy an owl or currentcost current transformer separately to "roll your own" - about £7 -> £10.

Have a look at this for the soundcard system:-

[Fred]

Thanks for the clarification, I was confused about the phrase "historical data".

[Fred]

Maplin seem to stock a variety of meters:

at 14.99 looks like it may be the same as sold by CPC. Does anyone know anything about these models?

L61AQ has been recommended in this group; is it the kill-a-watt model? But the disadvantage is no battery back-up.

I think that N67HH has battery back-up so that it keeps the data when unplugged for easy viewing.

Does anyone have experience of any of these (or other) models?

TIA

[Bob Minchin]

Fred, I don't know if you are after an accurate result but in a recent inquiry to Maplin, they replied to me that none of their products currently calculate true RMS power. ie the sum total of instantaeous voltage*current at the same instant. This means they will likely be incorrect for anything with a switch mode power supply, TVs, Videos, computers, modern low energy light bulbs etc and also be incapable of accurate measurement of anything with a motor in it- fridges, freezers, hoovers etc.

Does not leave a lot in a modern household!

What they will do is enable you to track down things consuming power all the time that you might have overlooked in any economy drive.

Bob

[Fred]

Crickey! What's left?

It depends what you mean by accurate. I don't need to know to the nearest tenth of a watt or anything like that but on the other hand, I don't want completely meaningless results either.

Fridges and freezers are on all the time, or should I say plugged in all the time (I appreciate their thermostats switch them on and off throughout the day and night). It would be interesting to know how much they use.

I'm also curious to know how much it costs to run the dishwasher, washing machine, tumble drier, etc. That said, I'm not sure the results would change our habits: the clothes still need to be washed and the food still needs to be chilled. Switching these off isn't really an option!