Alex van den Bogaerdt wrote: >I may be asking for help myself soon; I'm thinking about a >webcam, a led (for illumination) and some ocr software to >read my own meters. That, or a smarter idea on how to automate >reading those meters.
I assume then that you still have the old mechanical "Ferraris Disk" meter. I would look to see if there's any way you could focus a sensor on the disk which will have some markings on it - IIRC there are lots of stripes around the edge (high frequency, high resolution) and some larger markings (such as one/revolution). Ideally you would like to mount a reflective sensor close to the disk surface, but your utility supply company will not be amused if you break the seal and start fiddling with their meter ! If you could achieve this then you'd have just the same system as the OP - one pulse every X number of watt-hours. Or ... WARNING - DO NOT try this without adequate knowledge/training ! It may be simpler to install your own private meter downstream of the main meter. All it requires is to drop the tails out of your distribution board, put new tails from your meter to the board, and put the original tails into the supply side of your meter. A quick look around gives a number of suitable units, generally in the region of £100-£150 (or something like ¤150-¤220). Even simpler would be to get a meter unit that has an external CT (current transformer) and use a split CT - ie one with a core that splits into two pieces so it can be put around a cable instead of having the cable threaded through it. That would eliminate the need to disturb your main cables at all as the unit can take it's voltage feed from an output circuit from the distribution board, and the CT can be clipped around a main feed cable without disconnecting it. If you REALLY want to DIY it (and have the skills to do it without killing yourself or burning the house down), then there are chips to allow you to build your own. See http://www.analog.com/en/subCat/0,2879,760%255F790%255F0%255F%255F0%255F,00.html, and in particular http://www.analog.com/en/prod/0,2877,ADE7753,00.html which does all the complicated stuff and has a serial port ! _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
