On 11/26/2016 07:58 AM, alan.b.pearce@stfc.ac.uk wrote:
>> But, I'd like to access the Landis & Gyr smart meter to get more detaile=
d
>> information from it and to continue research into power factor correctio=
n for
>> these new fangled LED bulbs.
> I would have thought that to get their 'green' credentials the LED bulbs =
would have power factor conversion ICs as their front end so the power fact=
or should be better than 0.9.
>
> However to investigate this, rather than hacking a meter you have on hand=
, it may be better to look at the app notes Microchip have for power meter =
applications (I seem to remember one using an 18F chip with external app sp=
ecific AD converter) so you can get at the info you want.
>
> See http://www.microchip.com/design-centers/utility-metering-solutions/po=
wer-monitoring/overview for further info.
>
>
>
Thanks Alan,

I did check out the microchip site and was floored with the low cost of=20
the chips and their capabilities. I wish I had looked earlier!

Power factor for pulsed loads, such as an LED light bulb gets messy and=20
a full blown solution is not able to fit within the confines of the bulb=20
itself. And, reading the real and reactive power for a device that=20
doesn't have a sine wave current draw is not trivial.

I bought 3 different LED bulbs from Home Depot and Walmart, they have=20
power factor values between .47 and .6!! Later I got some energy star=20
rated bulbs and they measured .88 to .92. I'm thinking of dissecting the=20
energy star bulbs just to find out what makes them tick.

GL.

Art



--=20
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