Home lighting: 12v or 220v ???

[jean63]

What bothers me a bit is that I would no longer know what to do with all the transformers that are connected to my lamps

.
That's why in the end, I didn't change anything.

1 - Above all, turn off the lamps that don't light anyone.

2 - Use your household electrical appliances that consume a lot of energy sparingly.

I think the light is peanuts on the bill if we manage well.

[Get up]

I hesitate I hesitate I hesitate
I decided to offer myself this little change for my birthday yes I know it's weird but I wanted to try to consume less and that it is not my household that pays but it is true that an intelligent use of light will probably allow me to save more than tt replace at a high price.

[Targol]

To return a little to the subject and for those who the question of the comparative losses of a circuit in 24V and and 220V interested, we have, with ThierrySan, made a small calculation on the last pages of this subject.

You can go take a look. Otherwise, for lazy people, the result of the races is as follows: to have losses equivalent in 24V to those of a 1,5mm² circuit in 240V (aproximation to simplify the calculations), 24V wires would be required 14mm in diameter !!!

Now, the question remains posed to know if, on the lengths of wiring of a house not too big (max 30m for a given circuit), these losses are reasonable or not in 24V.
It could also be interesting to compare the losses of a DC low voltage wiring with the losses due to the efficiency of 220V ~ -> 24V- transformers.

[ThierrySan]

Seen Targol!
We already had a hard time getting to the end of the idea, so if you have to redo the cocks ... I'll let you do LOL

On the other hand, Jean63, you speak of switch before the transformer ... I do not think that it is done. Because an inductor is considered more as a current generator than as a voltage generator. So if we open the primary circuit of a transformer always on load on the secondary, we risk creating very important and dangerous electric arcs due to this. to my transformer choke This is why we prefer to put the switch on the load, therefore on the secondary of the transformer.
Maybe someone could confirm ?!

[Stellah]

Hello,
Without hesitation of the 220V which will allow you to put either economical bulbs, or LEDs, the 12V dichroic bulbs will disappear, that said between the LED and the economical, you have to see what use you will make of your living rooms permanently lit or not knowing that an economical lamp requires a heating time while the LED reaches its maximum output immediately.

[Exnihiloest]

The power is equal to the product UxI where U is the voltage and I the current (I thank you for the cos (φ)).

So a priori the voltage we don't care, whether we have 230v 1A or 12v 19A we will consume 230W (in Europe, the mains voltage is normalized to 230V, not 220).
but:
line losses are proportional to the square of the current, not to the voltage, which is why we use high voltage lines for long distances
so :
with equal length of line and cross section of conductor, it will always be advantageous to use the largest voltage, which will reduce losses in the line whose resistance dissipates part of the current in heat. And if to reduce losses online we pass 230v and we convert it to 12v on arrival, the loss in the transformer is also to be seen.
It must be seen that the difference in line losses is considerable: (230/12) ² = 361 times greater with 12v than with 230v with equal line and transported power.

As far as light sources are concerned, we know how to do it at different voltages and with similar yields, so voltage is not the criterion of choice. Obviously what matters is the number of lumens supplied in relation to the electrical power consumed (not forgetting also the directivity), and there is no picture, LEDs are to my knowledge the most efficient.

The 12v has an advantage in security, which even allows to have uninsulated conductors like these installations that we see today with 2 parallel rods, across the room along the ceiling, and on which we can connect LEDs at the desired locations

[plasmanu]

State company State Grid Corporation of China reports having commissioned, on December 31, 2018, an ultra-high voltage direct current line of 1 kV capable of transmitting 100 GW over more than 12 km between the North West and eastern China. A triple record.
https://www.industrie-techno.com/articl ... pays.54779

[Exnihiloest]

With 1A and 230V, we transmit a power of 230W.
With 1A and 1MV, we transmit a power of 1MW, with no more losses than in 230v. We understand all the interest of high voltage.

There is another source of losses: radiation and induction. This is what is resolved above by the use of direct current instead of alternating current (I wonder how they manage to rectify such voltages! A pack of large diodes in series?).
In a house, it would not be interesting because the line lengths are so short that they radiate almost no energy.

[plasmanu]

Very well. But the intensity square is for very old school textbooks from the XNUMXth century.
We are in the XNUMXst now.
I imagine this system in the USA. It's 50% of not lost for nothing, given the distances

[izentrop]

how he can relieve such tensions! A pack of large diodes in series?

IGBTs, a whole package in multi-levels https://fr.wikipedia.org/wiki/Courant_c ... veaux_(MMC)

The reality exceeds the fiction by seeing the mouth of the transformers ... The do-it-yourselfers with their tesla coil only have to get dressed
https://press.siemens.com/global/en/fea ... ransformer