Now that the cold weather is here (arrived early this morning, I can see snow on the nearby peaks brrrr!) I thought I'd start an indoor project as the shed is too cold to work in.
An energy monitoring system has been selected as the lucky candiate. There's lots of these around but I like the open source one from
OpenEnergyMonitor.org. . It''s Arduino based using 433MHz or 915Mhz wireless communications. Typical sensors are current transformers with an optical detector for use with smart meters.
The problem I have is that my meters are older analogue, rotating disk type so I need a reliable method to detect disk revolutions (266.6 revolutions per KWH) I've found a few LED based detectors after a bit of browsing but some of them are a bit rough and unreliable.
SoI thought, if there's anywhere to ask about this, it's here.
Before anyone points out that the wires are visible and that I could connect current transformers to them, it's illegal to do such a thing unless you're a licensed electrician and I doubt that an electrician would install a device behind the insulated layer end bring wires out to the front, even though those CT's have no electrical connection. Smart meters are being rolled out but only for new installations or to replace faulty meters. As you can see from the meter box, I have three very similar meters and some sort of timer switch.
What I'm looking for is a simple design for an optical sensor. The disk has a black mark on it so that the rotation can be seen and it's behind glass. The device also needs to unobtrusive so that the meter readers don't report it. Another thing is the the data transmitter unit is battery powered so power consumption is to be considered.
So get your thinking caps on or get get your fingers googling and do my job for me
There may be a small prize for the best option
Important: I'm sure that someone will suggest just going ahead and connecting up what I want. It's not just against the electricty suppliers rules but it's also illegal as far as state legislation goes so I won;t be doing that (penalties can include fines and if someone is seriously injured, incarceration!)