13 amp plug power meter - any recommendations?

trouble wih almost all 'power meters' is that they dont measure RMS power, they tend to measure VA or some approximation to RMS that falls down badly when faced with a switched mode power supply

Unless you know how they are measuring the power, be careful.

The one I have (somewhere!) can be switched between power in W and power in VA, and gives the same result for a lightbulb (being resistive) but different results for anything with a switched mode power supply. That was a bog-standard meter from Maplin (RIP). It also had a setting that calculated total energy used (ie power integrated over time) in kWhr.

Every appliance like this has the power consumption marked on it somewhere visible.

If you Google, the average power consumption for a plasma is 140 watts. Average for a modern LCD 90 watts. Both will depend on screen size.

Unless you're TV is on 24/7, I doubt you'll notice the difference in running costs.

Also, a modern smart TV which is online all the time - even in standby - may actually use more electricity in standby than an older set.

Does that realy matter that much unless you want better than 5% accuracy an d even them you might not know how they measure your power usage does your energy supplier use RMS or average how much to they account for the phase s hift caused by SMPS in computers and TVs and most devices now. I'm not sure whether or not it matters whether it's RMS or average at this scale.

I have maplin versions at home and at work, they have always been OK for su ch things and pretty much given me the info I needed.

You may be able to just look up the manual online and see what it says are the standby (hibernate) and active power consumptions.

If it is an older model then it may well default to powering the digital tuner continuously so it is worth probing the menus carefully and disabling that feature. My LCD TV went down from 20W to

Good enough to show you one or two significant figures. They are a bit flaky on low power devices and switch mode PSUs but better than nothing.

Even so you will find some devices that consume unreasonable amounts of power when they are supposed to be "off". My PC sound system consumes as much when switched off as it does when on. The on/off switch merely disconnects the inputs to the power amplifier and the on LED!

Offending items are now powered from smart sockets that switch everything off when the PC is either in standby or off.

Worth taking a quick look in Maplin to see if they have any at 30% off.

It is probably worthwhile having a whole house monitor with realtime display if you want to shave ~10% off your electricity bill. Reducing your 24/7 base load to under 100W will help save money.

I have the Owl (other brands available some free from your electricity company if you chose the right supplier and tariff).

If the TV is really bad it will easily show up on that when you switch if on. Resolution is to nearest W but accuracy is more like +/- 10W or

I have a Maplin one, I don't think it claims to measure true RMS, but it does allow toggling between W and VA, it's measuring my PC's consumption now at 35W and 58VA.

n.b. that isn't on direct mains, it's between the PC and a UPS which is running in buck mode at the moment, so not likely the sineyist of sine waves.

... be bloody difficult, the lowest I generally see mine overnight is

So how much would you say your electric company charges you to have the PC on for say 10 hours is they charge 20p per KWh ?

As I tried to imply the accuracy isnt that important and I assume whether yuo measure true RMS, RMS, average, peak, or pk-pk a TV that measures 50W or 50VA will cost you less to run than a TV measuring 80W or 80VA.

but you can elimante these problems by using teh same test equipment and variables.

It is about what mine is. Router, alarm, emergency lights, cooker and a host of gadgets in standby/sleep mode. I could get lower if I found a router that would go to sleep when there was no internet/wifi traffic.

It is worth poking around to see what else is drawing power.

Domestic electricity meters all measure Watts rather than VA, so 7p at that price.

I'd have to reboot the PC to plug it into the mains, measure and then reboot again to put it back onto the UPS ... not convenient at the moment.

Yes they used to be wrong on old telies that only rectified on one mains half cycle of course too.

Brian

Might try CPC then, in the absence of Maplin any more, or look at reviews on Amazon. Brian

I'd say check anything with an older none SMPS plugin PSU

OK I'm guess I'm lucky I have a Mac which can be swithced off and rebooted in under 2 mins. ;-)

UPS (probably the largest constant draw, it's warm) fridge-freezer (periodic rather than 24x7) toothbrush and clippers charging in bathroom cabinet oven and microwave flashing "12:00" router/firewall/access point DECT basestation + 2 phones in charging cradles alarm

If I leave a PC or laptop running overnight, can't get below 150W

I didn't realise Macs carried on working even when switched off, now I can see why people pay extra for them ...

Since you presumably always use it in combination with the UPS why not unplug the UPS from mains interpose device and measure the PC+UPS.

AFAIK, that's just the DAB radio which is 2A@9V and runs at about 45°C day and night (11W on, 9W standby)

They don't but then again I don't run anything in the home from my Mac or M ac mini, or at work.

That's true people do but perhaps that's not the reason, when I came in to work 2 weeks ago there had been a power failure must have been a glithic as my Mac was still up and running most PCs had all rebooted, the server runn ing the print station stopped working and on reboot I had to phone IT to ge t them to re-inialise the server. None of the studetns could enter the buil ding as the card access system had also failed, this is a know problem in t hat if it goes off and even though it comes back on again it looses permiss ions, but everything was back up and running OK within the hour.

On other occasions I've been here in front of my mac and the lights dipped , I heard a number of studetns complain that they lost work and the PC went off, but my mac stayed on, of course this is NO reason to spend more on a Mac but it;s nice to know a small glitch won't wipe out what you're doing a s it could be something important like a game. ;-D