Consumption of an electric transformer

[Obelix]

Hello,

To answer the various questions:
The transformer is calculated at nominal POWER.
So an empty transformer consumed but there is no specific typical curve. It is far too dependent on the construction.

Leaving a transformer plugged in is always harmful to econology. This is for sure!
How much ? a ladder order of magnitude: one tenth of the nominal power of said device.
But most of our modern devices no longer have a transformer!
What is even worse!
All TVs, HI-FI systems, VCRs, DVD players, various answering telephones, etc. have a decoupage power supply which remains on, sometimes even if the device is "cut", the mains plug must be removed to that there is no more consumption.
There is also an order of magnitude of consumption at "VACUUM" of the order of a few watts 3 to 5 per device (basic consumption of the decoupage power supply)

When you take stock of a "standard" house, it's really edifying.
Two TVs, a video recorder, a HI-FI chain, DVD player, cordless telephone, "internet" type BOX connection, mains alarms, we quickly reach hundreds of Watts 24/24.

The only truly reliable solution is to cut off the mains with a switch either on the socket or on the electrical panel or if you are not at home, a multi-socket "racket".

Obelix

[delnoram]

Quite for the useless operation of a transformer, there are solutions, say basic that everyone can implement if we take the time.
But in the following case
https://www.econologie.com/forums/campagne-d ... t2115.html


expandable to many others, it would be nice to be able to reduce the consumption to half less, no (if it is possible, anyway I will try the experiment )

[delnoram]

Well, I rummaged a little in my cupboards and I found a sheet metal transformer whose empty consumption is not readable on the PM230.

The small experiment is to replace the power supply of my modem router (Linksys brand).
The complete original system (power supply + router) consumes 18.72W
(be careful, however, to keep in mind that the PM230 wattmeter only has a precision of 0.01A, in this case the sector is at 234 Vac, hence my choice to give you only the high rating of measures).

The assembly: my transformer +4 diodes to rectify and a 25v 2200µf codensor to filter (these last elements belonging to the Linksys power supply in order to properly measure the difference between transformers.

new power supply: 11.7W (still under 234Vac).

Conclusion, with 1 transformer better suited in this specific case we gain 7W.

Yes it's not much, but small streams make the ...................

Closed file

[Other]

Hello

hi Andrew
Gourmand is between Quotes, it begs the question
the watcher gives us what to measure:
Power Active or Active + Reactive?

A wattmeter measures active power
A bad cos in an installation causes too much amperage to circulate and this amperage generates thermal losses in the lines and in the windings and these losses are in watts

To know if a wattmeter actually measures the active current, it suffices to have it measure an unpolarized capacitor (15 to 30 microfarat), normally if it passes a few amps under 220 volts it should hardly measure anything just the thermal losses of line or of connection.

For transformers, the bigger the better the efficiency
The yield is calculated at its nominal value, which is why the empty yield is bad.
Normally for economic reasons to build, the winding of the transformer (the number of turns of the primary is calculated so that it draws a little current without load, it is necessary to put a lot more turns so that it does not pull anything empty. and therefore also increase the secondary) in practice we put the minimum turn on the spools and the minimum wire size.
this explains the poor performance of small transformers.
We must not forget the rectification and the voltage regulators which follow the transformer, they also have a consumption.
it's not complicated anything that heats up lowers the efficiency.
I explained last to son who thought that his starter was too weak, touches all the big connections that of the battery, the starter and that of the mass, if it is hot there is a loss .. dismantled, cleaned and tightened. .
When you live in a fully electrically heated house, letting this heat spread throughout the house or leaving the lights on does not change much to the total consumption, the heating radiators work for less time, (provided it is cold.)

Andre

[delnoram]

Hello
Measure on the PM230 Wattmeter with 3 capacitors of 10µf each.

Results: 45w
2.18 Amps Cos (phi) 0.09 230Volts

which mathematically seems to be correct.
but is the measured Cos (phi) good?

[Other]

Hello,
Seems correct to me as a value
both the cos and the wattage which depends on the construction of the insulation capacitors, although 45 w is a bit big.
this aurriat given in volt ampere 500 VA

Now cut everything in the house and just plug in the capacitors, if you have more it's better, and count the turns of the counter wheels, see if that matches your watt or your VA (it wasn't the case). at home despite the controversy with hydro specialists, nothing like measuring and talking)

Andre

[Castor]

Bonjour.

it would be possible to have the technical characteristics (or even the technical sheet) of the watcher who used to make the measurements?

[delnoram]

Bonjour.

it would be possible to have the technical characteristics (or even the technical sheet) of the watcher who used to make the measurements?

Hello Beaver (Hello pollux too after all you are the mythological twins : D)
This is the PM230 on sale in the ecological store, a consumer Wattmeter .

[Castor]

Bonsoir.

Pollux, take a ride (joke at 3F but could not prevent me!)

Yes, I found the doc in the economology store. The detail I wanted to know is that bandwidth, I found it (From 40 to 70Hz)

I am not sure that this allows short measurements on electronic devices, because of current harmonics.

[delnoram]

Yes, I found the doc in the econology store. The detail I wanted to know is that bandwidth, I found it (From 40 to 70Hz)

I am not sure that this allows correct measurements to be made on electronic devices, because of current harmonics.

Hello,
You mean that the harmonics could distort the measurement, but in this case would the measurement be higher than normal or depending on the case + or -?

If we measure 2 fluorescent bulbs at the same time the consumption in Watt and less than the addition of the measurements of the 2 bulbs
separate (no voltage drop), same thing with an Ammeter

2nd ex. the power supply (remote control receiver) of a roller shutter consumes 9.12W (228 V) (at rest), if I plug in a small power supply transformer of a low-voltage appliance to the consumption. goes to 6.84W (228 V) and of course the same with an Ammeter

This is my problem, does anyone have an explanation?