Mains Power Meter

[Tony]

Can anyone recommend a mains power meter?
I have this one
http://www.jaycar.com.au/productView.asp?ID=MS6115
It basically works for me, but the power factor reading appears to be
wrong, which is not helpful when you want to work out standby consumption.

 

[Bob Milutinovic]

"Tony" <nomail@nospam.com> wrote in message
news:m7svao$448$1@dont-email.me...

Can anyone recommend a mains power meter?
I have this one
http://www.jaycar.com.au/productView.asp?ID=MS6115
It basically works for me, but the power factor reading appears to be
wrong, which is not helpful when you want to work out standby consumption.

I can't directly endorse any as I've never needed much precision from them.
I have an Aldi one which I use for occasional approximations, but I'm
rounding to the nearest hundred watts.

This device seems like it could be precise enough for you, though its major
limit is a 1A maximum current draw. Specified resolution is 1mW;
http://www.aliexpress.com/item/-/1711278559.html

This hard-wire all-singing/all-dancing unit explicitly touts standby power
measurement as a feature;
http://www.aliexpress.com/item/-/947583817.html

--
Bob Milutinovic
Cognicom

 

[Tony]

On 30/12/2014 12:14 PM, Bob Milutinovic wrote:

"Tony" <nomail@nospam.com> wrote in message
news:m7svao$448$1@dont-email.me...
Can anyone recommend a mains power meter?
I have this one
http://www.jaycar.com.au/productView.asp?ID=MS6115
It basically works for me, but the power factor reading appears to be
wrong, which is not helpful when you want to work out standby
consumption.

I can't directly endorse any as I've never needed much precision from
them. I have an Aldi one which I use for occasional approximations, but
I'm rounding to the nearest hundred watts.

This device seems like it could be precise enough for you, though its
major limit is a 1A maximum current draw. Specified resolution is 1mW;
http://www.aliexpress.com/item/-/1711278559.html

This hard-wire all-singing/all-dancing unit explicitly touts standby
power measurement as a feature;
http://www.aliexpress.com/item/-/947583817.html

Thanks Bob. One is too pricey for the job, and the other one needs a
reference. Meaning, is it actually better? Chances are they are all
using the same chip set.
I could imagine a bit of circuitry could measure the co sinus as well,
that's all I need really, to verify the actual power consumption.

 

[Phil Allison]

Tony wrote:

I could imagine a bit of circuitry could measure the co sinus as well,
that's all I need really, to verify the actual power consumption.

** Computing cos phi is not gonna get you anywhere with electronic devices.

You must use the basic definition of PF which is VA/Watts.

Watts is computed by multiplying many samples of the voltage and current waveforms over a whole cycle and averaging the result.



..... Phil

 

[Phil Allison]

Phil Allison wrote:


You must use the basic definition of PF which is Watts / VA.



.... Phil

 

[Tony]

On 30/12/2014 12:14 PM, Bob Milutinovic wrote:

"Tony" <nomail@nospam.com> wrote in message
news:m7svao$448$1@dont-email.me...
Can anyone recommend a mains power meter?
I have this one
http://www.jaycar.com.au/productView.asp?ID=MS6115
It basically works for me, but the power factor reading appears to be
wrong, which is not helpful when you want to work out standby
consumption.

I can't directly endorse any as I've never needed much precision from
them. I have an Aldi one which I use for occasional approximations, but
I'm rounding to the nearest hundred watts.

This device seems like it could be precise enough for you, though its
major limit is a 1A maximum current draw. Specified resolution is 1mW;
http://www.aliexpress.com/item/-/1711278559.html

This hard-wire all-singing/all-dancing unit explicitly touts standby
power measurement as a feature;
http://www.aliexpress.com/item/-/947583817.html

Got this one
http://tinyurl.com/lpgr5dr
Measures a realistic figure. A PF of 0.08, where tho other one indicated
100%.
Jaycar appears to stock the same product for double the price, with a cable
http://www.jaycar.com.au/productView.asp?ID=MS6119

Tony