Drain on Electric Power Supply

[JohnD]

I have an energy monitor which is not very accurate below about 300W

However, all the significant loads (kettle, dishwasher, tumbledrier, toaster, electric heater) are resistive and it is very accurate with them. The larger loads are the ones where I look at possible economies.

if I look at its usage graph, it says the overnight usage is about 250W, which will be appliances on standby, burglar alarm charger, porch light, and not costing me enough to worry about. If I cared enough to verify it, I could take the meter reading at, say, 1am and 7am, but I don't suppose the information would be any use to me.

BTW some digital meters flash at 800 imp/kWh. I don't know why. 1000 seems much more convenient. I have a note of the brand somewhere. Once you know, you can estimate usage by eye, just looking at the flash rate.

 

[SUNRAY]

timing the interval between two flashes is sufficient. You can time three or more to increase confidence.

"The majority of meters are labelled 1000 Imp/kWh which means that the LED will flash 1000 times for each kWh of electricity which passes through. The rate of the flashing of the LED tells you how much power is currently passing through the meter

One flash indicates 1Wh."

Checked my daughters: 640/KWh. Seems silly to not standardise.

 

[ban-all-sheds]

The larger loads are the ones where I look at possible economies.

Here's an economy measure:

Never have anything switched on unless you need it on.​

You'll find that you don't need a monitor to help you implement that measure.

 

[JohnD]

how many times do you think you have to repeat that before people will suddenly change their minds?

I am at liberty to run my appliances more or less often, according to my personal whim. I am at liberty to take into account the actual cost of each cycle when making my decision.

I happen to choose to leave my 4W LED porch light on at times when some other people might consider it unnecessary. If I choose to leave it running 24x365 it will cost me nearly £5 a year. I don't care.

If I did the same with a 3kW convection heater it would cost me a great deal more. I do care.

Unlike you, I do not treat both items with the same importance.

 

[securespark]

My crummy Plusnet router gets quite hot!

 

[SUNRAY]

My crummy Plusnet router gets quite hot!

But I bet it's on a 10W walwart, not 45W

 

[securespark]

18W.

 

[SUNRAY]

18W.

I guess the router doesn't use that much tho'

 

[securespark]

Not sure, but it does get surprisingly hot.

 

[ban-all-sheds]

how many times do you think you have to repeat that before people will suddenly change their minds?

It's not a case of changing your mind, it's a case of you coming to understand something.

So to answer your question, every time you show that you still don't understand I will explain it to you again.

I am at liberty to run my appliances more or less often, according to my personal whim.

Of course you are. But please be aware that if you run them unnecessarily you will be generating unnecessary expense. And you do not need a monitor to be able to have that awareness.

I am at liberty to take into account the actual cost of each cycle when making my decision.

Of course you are. But please be aware that any cycles which are not needed will generate actual costs which you do not need to incur. And you do not need a monitor to be able to have that awareness.

I happen to choose to leave my 4W LED porch light on at times when some other people might consider it unnecessary.

You must have your porch light on when you consider it necessary, not when others do. It's your porch light, not theirs.

If I choose to leave it running 24x365 it will cost me nearly £5 a year. I don't care.

Fine. But please be aware that whether it be £5 or £5,000, if you run it when you don't need it on them you are incurring unnecessary expense. And you do not need a monitor to be able to have that awareness.

Please be aware that if you have it on because you want it on but you don't need it on then you want to incur unnecessary expense. And you do not need a monitor to be able to have that awareness.

Please be aware that if you don't care whether you need it on then you are incurring expense which you don't care about. And you do not need a monitor to be able to have that awareness.

If I did the same with a 3kW convection heater it would cost me a great deal more. I do care.

You do not need a monitor to know that a 3000W heater costs more to run than a 4W lamp.

Unlike you, I do not treat both items with the same importance.

Please be aware that a policy of simply not running things unnecessarily has no importance judgements. And you do not need a monitor to be able to have that awareness.

 

[SUNRAY]

Not sure, but it does get surprisingly hot.

My TP link wallwart is 12V 2A, router states 12V 1.5A on the label.
That gets quite warm and we stand it on a couple of pencils to add ventilation.
Highest DC current I've been able to measure on a cheap DVM is 260mA which would be 4.6W at 12V.
Plug in power meter shows about 3W at idle, a peak of 8.2W and since 09:32 a cumulative of 14.7W.
I guess this is fairly typical.

 

[John D v2.0]

My TP link wallwart is 12V 2A, router states 12V 1.5A on the label.
That gets quite warm and we stand it on a couple of pencils to add ventilation.
Highest DC current I've been able to measure on a cheap DVM is 260mA which would be 4.6W at 12V.
Plug in power meter shows about 3W at idle, a peak of 8.2W and since 09:32 a cumulative of 14.7W.
I guess this is fairly typical.

But also ridiculous yet entirely understandable for something not really regulated and chosen entirely on price. My phone can do far more on much less power.
Although when the EU have finished with light bulbs, vacuum cleaners, and large appliances, maybe well see mandatory efficiency labels and minimum standards on routers too.

 

[endecotp]

My first cable router, circa 2000, had an external wall wart with a relatively high output voltage, something like 18 V, presumably because there was one component in it that needed a supply voltage of that sort. Then internally it had linear regulators down to 5 V and maybe 3.3 V to supply everything else. These got pretty warm and meant at least two thirds of the power was wasted.

At around that time I was working on a product which ended up with a 5 V external supply, an internal switch mode converter to 3.3 V, and a couple of linear regulators down to 1.8 V and 1.2 V. The main reason for using the linear regulators for the lower voltages was that switch mode regulators take time to start up and stabilise, and the microprocessor we were using had quite strict requirements about the order in which the various supplies had to turn on. Getting this right would have needed more design effort and risk, as well as more components and cost; our linear design was simple and right first time.

The most recent products I've been involved with do everything using switch-mode regulators. This is partly because you can now get "power management" ICs that combine the switch mode controller with the necessary timing circuits for startup and shutdown, and possibly also things like suspend modes, battery charging and so on. Often these PMICs are specific to particular microprocessors and using them is just a case of copying the reference design.

In the case of broadband wireless routers, the limitting thing is now largely the interfaces. To improve this you generally need the devices at both ends of the link to cooperate. Ethernet is spec'd to drive 100m of cable, which needs significant power; WiFi radios also take significant power when listening, even if there is no data to receive. So we now have IEEE 802.3az "energy efficient ethernet", where the two ends determine the cable length and reduce their output power as necessary. There are similar efforts for WiFi.

My phone can do far more on much less power.

Phones are expensive and power consumption is critically important for the users.
Technologies that are develoed first for phones (and laptops) will eventually trickle down to other products, where the customer is more price-sensitive and less concerned about energy.

 

[securespark]

we stand it on a couple of pencils to add ventilation.

The high-tech solutions are the best...

 

[JohnD]

every time

You are wasting your time.