LEDs & Transformer

[hard-work]

I do believe that LED bulbs last far longer when they are 12v and not 230v, as they operate on 12V anyhow. Is that so?

If so, what do many think of having a 12v lighting circuit with a 230v to 12v transformer at the CU? Would it be a better solution, than replacing expensive bulbs? OK if the transformer fails the whole house is out, so that is the downside.

 

[Taylortwocities]

If so, what do many think of having a 12v lighting circuit with a 230v to 12v transformer at the CU?

Not a great idea. Volt drop will be the enemy of running 12v over any appreciable distance. That's why 'transformers' tend to be close to the lamps.

 

[bernardgreen]

I do believe that LED bulbs last far longer when they are 12v and not 230v, as they operate on 12V anyhow. Is that so?

No it is not so

A LED lamp has a a power convertor and an LED element that converts electrical energy into light.

The power convertor has to control the current that passes through the LED element and not the voltage. The voltage that appears across the element when current flows through it is determined by the type of LED element ( V f or V forward ) LED elements producing white light create a voltage typically about 3 to 4 volts.

The life of the LED element is longest when the current put through it is constant and less than the maximum continuous current the element is rated at.

Some power convertors in lamps produce a constant current and the LED elements these lamps will last longest.
Some produce pulses of current that are higher than the maximum continuous current but average ut to be less than the maximum continuous current. The LED elements driven by this type of convertor will have a shorter life span.
The wrose type of convertors apply a voltage to the LED element that is very slightly above the LED V f voltage and depend on stray resistance in the element to control the current. These elements will have a shirt life if the voltage supplied is too high.

So it doesn't really matter if the lamp is 230 v or 12 volt. It is the qualiity and design of the power convertor that matters.

Many short life Christmas decoration LED light strings that run directly from a 3 volt battery ( 2 AA cells ) use LED elements with a resistive layer built into the element intentionally to control the current when 3 volts is applied.

 

[bernardgreen]

think of having a 12v lighting circuit with a 230v to 12v transformer

I have seen a house wired for 12 volt lighting. ( or was it 24 volt ) simply because they depended on a generator for power. Batteries for the lighting meant the generator did not need to run at night. Thye used the copper pipe work for most of one side of the supply and heavy cable for the other side

 

[hard-work]

I have seen a house wired for 12 volt lighting. ( or was it 24 volt ) simply because they depended on a generator for power. Batteries for the lighting meant the generator did not need to run at night. The used the copper pipe work for most of one side of the supply and heavy cable for the other side

Thanks for the explanation of LED bulbs. Most welcome. This brings up another Q. So how do we know what is the best, and most stable LED to buy? The LEDs that will last. Price is not always the guide.

This 12v lighting from a genny. They used copper pipe as cable? PVC wrapped soft copper pipe I suppose could be used and maybe cheaper as well. Put it in plastic trunking and its is safe for sure. Inventive. Caravans use 12v lighting to also run on batteries. I read in a Caravanning web site that some guys change the bulbs to LEDs and never have to worry about the battery running down as it will last well over a week. Beforehand they had to start the engine to charge up the batteries.

 

[bernardgreen]

This 12v lighting from a genny. They used copper pipe as cable?

The genny was 230 volt and this was wired as was standard practise for 230 volts.

The genny re-charged the batteries and the positive side of the battery was connected to the pipe work and to ground so the pipe work did not need electrical insulation.

Positive to ground as that results in less electrolytic erosion of copper.

 

[hard-work]

The genny was 230v and charged a battery at 12v? Bernard I think you missed something there.