Standby power consumption measurement

Given up trying to measure this on my LCD TV (egg see

formatting link

But could someone enlighten me as to how the TV manufacturers do it? What type of equipment would they use to measure these low consumptions from power supplies using (very) irregular waveforms?

--
Jeff
Reply to
Jeff Layman
Loading thread data ...

I don't think they worry very much about irregular waveforms. I think they pretty much assume you will be using it on normal power grid. So a regular wattmeter or equivalent would be okay. Or, an AC ammeter, since they know the voltage reasonably well.

I also feel my manual will give me a reasonable value- why should they lie? My manual indicated my LCD TV has a negligible consumption when off, not the monster drains that some news broadcasts have touted.

Reply to
Don Stauffer

According to the forum thread I quoted, ordinary instruments do not give an accurate measurement of power consumption with standby power levels. I don't understand the technicalities (power factors, pulsed voltages, etc) as they seems to give pretty accurate readings when the TVs are operating normally.

And as to the figure quoted in the manual, not everything is as it seems ;-)

formatting link

--
Jeff
Reply to
Jeff Layman

Things called true power meters.

Graham

Reply to
Eeyore

That would give you VA ( apparent power ) NOT true watts. Please don't post about things you don't understand.

formatting link
formatting link
formatting link

Graham

Reply to
Eeyore

Or operating quite often too.

Read my reply.

Graham

Reply to
Eeyore

formatting link

What I consider strange is: Though I agree with:

the market?if a TV is spending 75 percent of its time in update mode consuming

20W, one expects someone on the testing floor should have noticed.

I must say, that it's not only Sony's fault. If the government distributes 'Energy Star' stickers, then they should have cwertification / measuring techniques, which capture such issues. As more and more devices are doing things like auto updates and other nanny work while officially being switched off, they might have to increase the time, they take for measuring.

Reply to
News123

Standby power consumption is increasingly having limits mandated by the IEC ( International Electrotechnical Commission ). Having standards that only apply in one country is rather silly.

The current goal AIUI is to get consumer goods down to 1W in standby. That's not ratified yet. Instead we have silly set-top boxes like the one supplied by my cable co that apparently does nothing other than blank the display when put in standy and consumes the same power more or less.

My CRT monitor does drop to 3W in standby though ( Sony 21" E530 ) which I reckon is pretty good. 130W active.

Graham

Reply to
Eeyore

But how much of a power factor does a modern piece of electronics have? Yeah, a motor or something with a very large inductor has a lot, but from what I have seen from the guts of modern heavy IC electronics, there isn't much in there to create a big power factor. No big deflection coils and stuff like that any more. Big enormous filter caps seem to have disappeared.

Reply to
Don Stauffer

Thanks.

But Google not much help here - only 39 hits for "true power meter", and many of those completely irrelevant.

Found one link which led to a Fluke 43B, but that cannot go down to 0.3w. Most of the relevant refs were for higher power measurement (eg those which could check house electricity meters). Other delving for lower power instruments only turned up those for RF power measurement.

Could you point me in the direction of an instrument which measures powers below 1w at 50Hz, or suggest other suitable search terms?

TIA

--
Jeff
Reply to
Jeff Layman

0.60
Reply to
Ken

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.