On Sun, 28 Mar 2021 01:13:16 -0400, micky
wrote:
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?
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
2) Automobile Quick Charge 3.0 ports? My car is old so I have to add
one, like this one,
https://www.amazon.com/gp/product/B0...MNGJUPVG&psc=1
Some 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?
The one in my truck draws less than 25Ma with nothing plugged in and
it is not switched.
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?
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
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.)
Again - my 50 inch plasma fraws about 0.2Amos when on "standby" My
cable box draws more - IIRC it was 0.3 amps
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?
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???
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**?
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"
** 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.