How much electricity do these things use when not in use?

[micky]

I'd appreciate it any replies went to all three groups that this is posted to so I don't have to read all three to see all the replies. When I started in Usenet, that was considered the proper way.

How much electricity do these things use when not in use?

1) Laptop power supplies, when the laptop is not on? Is it different when the laptop is disconnected?

2) Automobile Quick Charge 3.0 ports? My car is old so I have to add one, like this one,

come with a switch in them and some don't. I picked this one 'cause it has a 1.1" hole saw, not for the switch. I suppose some new cars come with QC 3.0 installed?

3) Radios, that have an on/off switch but the switch is not in the 110v. line. It's somewhere in the transistor circuitry, after the radio's power supply? Why don't they put the switch on the 110 volts?

4) Same question about TV's but since they are bigger, do they waste even more? If they have to use a relay, they could use a relay. (Yes, I agree that the remote control receiver has to be on all the time, but I don't consider that a waste. It could be the only part that is on.)

5) What have I left out? Especially something that is different in nature from the previous 4.

WRT 1, I've noticed that the black box that's part of the charging cable is not hot, not even warm afaict, when I'm not charging anything. Does that imply I'm not using much current? That I'm using no current?

WRT 2, cars, doesn't the alternator put out loads of extra electricity anyhow except that there is a regulator to stop that. If the charger I'm asking about or the lights or any accesorry (even maybe the heater fan) is using electricity, does it make the engine work harder? Is the amount significant? How many gallons an hour do all the accesories together use? Is the amount the engine would have to work to power a charger that's not charging anything even measurable with other than a galvanometer**? ** wikip doesn't say this but I was led to believe a galvanometer is an ammeter for very small currents. Was that true? Is it still? Anyhow, that's what I mean in the previous paragraph.

[Adrian Caspersz]

Yup - and *much* preference to multiposting. Cross-posting to completely different or trophy groups was the annoyance, mostly done by trolls.

It's less than the electricity used when they are in use ;-)

However less - this depends on age, construction, type, and how much power/cost you believe is significant.

Find yourself an AC plugin power meter and measure?

There are other metering methods for non-AC classes of equipment, a clamp meter is a non-invasive measurer of current (and them hall-types that also measure DC current are pretty useful in cars).

[angelica...]

Sorry, man. Google Fucking Groups won't let its users crosspost. (Although considering how much crap originates with GG, that's probably a good thing.) You'll have to read my reply in alt.home.repair.

They sure don't make tightwads like they used to:

Cindy Hamilton

[Jeff Liebermann]

Using my P4460 Kill-a-watt meter, I tried a mixed collection of laptops and power supplies. Since the laptop is charging the battery while it is turned off, and I didn't want to wait for the battery to come to full charge, I simply removed the battery where possible:

Acer Chromebook 14 PS only 0 watts PS with laptop turned off 0 watts

HP Pavilion dv8263dl PS only 0 watts PS with laptop turned off 3 watts HP Pavilion dv6-1253cl PS only 0 watts PS with laptop turned off 0 watts

[gfretwell]

I doubt it is really zero but a switched mode power supply plugged in with no load may not be enough to start counting on a Kill a Watt unless you left it plugged in for a really long time.

[Clare Snyder]

Depends. The newer smaller switch mode supplies draw VERY litle. My LenovoDuet power supply is 2 watts when plugged into the laptop - laptop off, battery 96% charged - and the same when not plugged into the computer. (0.2Amps) My Toshiba power supply for my 10inch tablet does not register ANY draws when not connected, .2amps when plugged in and charging.. When turned on it draws 0,22 amps

The one in my truck draws less than 25Ma with nothing plugged in and it is not switched.

Many have a "memory" or a clock that is powered when plugged in and turned off. I have onr that draws 0.2 amps on or off

Again - my 50 inch plasma fraws about 0.2Amos when on "standby" My cable box draws more - IIRC it was 0.3 amps

Everything in a car uses a little bit of power and affects fuel mileage - the question is, does it affect mileage in a measurable amount?? One horsepower os about 745 watts An alternator is something like 60 to 75% efficient depending on the make and model, and the efficiency changes with load - the heavier load the more efficient, to a point because the friction load doesn't change much. So - assuming middle of the road efficiency of 70%, every

745 watts of power drawn consumes ABOUT 1065 watts of input power, or just under 1.5HP Now take that charger - and assume it's a cheapassed chinese outfit and it draws 2 times what mine does -.05 amps or 0.6 watts - you can figure out the answewr to that question REALLY easily now, can't you???

1 watt is about .00134 of a horsepower so .6 watts is .00134x0.6= about ,0008 HP at 100% efficiency or .001 HP at 70% efficiency if my lousy math is correct. If the specific fuel consumption r of your engine is .37 lb per HP hour - average for a Toyota Prius engine - it would take .001X.37= 0.00037 lbs of gas per hour EXTRA to run that charger. Since gas weighs about 6.3 lb per gallon that is about 0.0025 gallons of fuel per hour. My math is a bit rusty - but I think I'm in the ballpark

Totally "gets lost in the noise"

[trader_4]

Very little.

Extremely little, some have an LED that's lit for example.

Probably to keep the setting alive in at least some designs.

I would guess it could be a few watts when off. Enough to keep the infrared remote circuitry going so it can be turned on.

That you're using very little.

Yes, the more loads, the more power it take to turn the alternator. How that translates into gallons of gasoline, IDK. But given you can run a 5000W generator for a good time on a gallon of gas, I suspect it's not much of a factor in gasoline consumption in a car compared to driving.

If the alternator is not charging anything, the amount is going to be negligible, it's just the friction losses in the bearings, etc.

AFAIK they were early ammeters and have been pretty much replaced by digital ones. That works for me.

If you're interested in finding out how much power 120V plug-in AC devices use, buy a Kill-a-Watt meter for about $20

[Tekkie©]

On Sun, 28 Mar 2021 01:13:16 -0400, micky posted for all of us to digest...

No, it wasn't.