LED drivers

[blackcabmal]

Hello

I plan on swapping 6x 12 volt transformers plus halogen down lights,for LED drivers and lamps,can anyone tell me what wattage the drivers should be.

Thanks

Murray

 

[bernardgreen]

The data sheet / technical specification of the LEDs you choose would be the best source of information about how to drive them.

 

[flameport]

It will be much easier to get 230V LED lamps and therefore not have separate drivers at all.

 

[winston1]

Hello

I plan on swapping 6x 12 volt transformers plus halogen down lights,for LED drivers and lamps,can anyone tell me what wattage the drivers should be.

Thanks

Murray

If they are all on one circuit you could probably run them all off one driver. In fact if they are ac/dc voltage driven types you could probably use one of your existing transformers. LEDs are usually max 5 watts so six is 30 watts. One of your transformers is probably 50 watt rating so would be OK.

 

[ericmark]

It has been raised a few times but here we go again.
1) A tordional transformer should be able to run most LED packages as well as quartz units.
2) A switch mode power supply often has a minimum wattage which precludes their use with LED lamps but not all some are rated 0 - X watts and will work.
3) Names can be swapped around but in the main a driver is rated in amps not volts however it is common for a DC power supply to be called a driver in the same way as an inverter is called a transformer.

So first question has to be what do the lamps say they require? Any AC unit what ever frequency is rated in RMS so 12 volt means peak of 17 volts this could mean an over load or an avalanche or zenor effect causing components to fail much depends on how the LED's are controlled.

Most MR16 packages use a switch mode driver within the lamp so anywhere between 9 and 20 volt AC or DC will work the lamps however some strips of LED's use simple resistors and may fail.

The real problem is they are often offered for sale with just 12 volt as rating with no +/- or any other voltage range. The GU10 often have a voltage of 90 to 250 volt and are easy to select but the extra low voltage versions are very lacking in information.

With such scanty information if using spots I would go for GU10 forget about any power supply be it transformer, inverter or driver just make things simple. With other LED units it's a case of following manufacturers instructions as we have little or no idea what is inside the strip.

If a simple LED with no control included then you have to consider power requirements v cost a simple resistor and full wave rectifier v a switch mode driver the latter have come down in price but really not a DIY project to work out what driver and what power supply feeds that driver.

My friends all radio amateurs have spent many hours experimenting with high powered LED's and heat sinks are a major problem. In the main they run them at around half the rated output as they don't want them to fail.

Heat sinks are complex calculations I did it to gain my degree but have no wish to do it again one really has to be a mathematical wiz kid to work it all out and calculus and imaginary numbers make my head spin so unless you have a degree in maths I would say don't bother.

 

[winston1]

1) A tordional transformer should be able to run most LED packages as well as quartz units.

Or any transformer such E and I laminated type.

 

[DaftPunk]

Most 12V LEDs will be expecting a DC supply and will not run off an old lighting transformer.

 

[winston1]

Most 12V LEDs will be expecting a DC supply and will not run off an old lighting transformer.

Some not most.

 

[bernardgreen]

A LED is just a diode that emits light when a DC current passes through it.

LEDs require a controlled DC current to be passed through them. The LED cannot itself control the current that passes through it.

A lamp that uses one of more LEDs instead of a filament is NOT a LED but is a lamp that uses LED technology. Invariably the lamp will have something that controls how current is put through the LED.

As Eric said there are strips of LEDs which only have a resistor to control the current and there are lamps with switched mode current sources built into the lamp.

The lamps with built in current controllers that accept a wide range of voltage are the easiest to use but may not be the best option.

.

 

[Aragorn84]

Most 12V LEDs will be expecting a DC supply and will not run off an old lighting transformer.

Some not most.

Often the 12v ones have a bridge rectifier in them anyway, as it means they work in either polarity for DC as well as AC!

 

[blackcabmal]

Thanks for the replies,much appreciated things are clearer now,one final point should i run ceiling lights and under cupboard lights separately?

Thanks

Murray

 

[ericmark]

1) A tordional transformer should be able to run most LED packages as well as quartz units.

Or any transformer such E and I laminated type.

Correct but reason I said tordional transformer was often switch mode power supplies have the words transformer on them and I suppose they do transform the voltage so can't really say it's the wrong name.

Same was a Vista is a device operating system so could be called DOS but we all know DOS is seen to mean command line interface (CLI).

As to how many lighting circuits we that's just personal. To me low level lights are to show direction of exit in a smoke filled room so would have them battery backed but I am sure that's no why your fitting them. In the pre-LED days yes separate circuits to reduce inrush but with LED no need.

I have ceiling lights and bed head lights in bed room on separate switches and find it handy to be able to leave one lamp one as back ground lighting so walking in with cup of coffee I don't need to switch on lights.

Hope I did not confuse too much I came to look for caravan lights so wanted up to 14.8 volt but found there is very little published as to what lights require. As it stands is very much suck it and see.

No GU10 or SES 230vac LED lamps in my house have failed. However the cheap 0.58W MR16 LED from pound land have failed they have not done very well at all. They are powered by a tordional transformer 200W rating at a £1 I am not worried but paying £5 for a lamp I would be. The whole LED lamp situation is a nightmare with lumen being measured in different ways so there is no comparison between lamps. Automotive lamps it would seem do have some rules like measure after they have been running 30 minutes but not general household types so in real terms you have not a clue what your buying.

 

[JohnW2]

Wildly off-topic, but ....

....reason I said tordional transformer was often switch mode power supplies have the words transformer on them and I suppose they do transform the voltage so can't really say it's the wrong name.

Even that 'definition' doesn't work - as you are aware, it's not uncommon to have a wire-wound 'transformer' whose output voltage is identical to the input voltage - so 'transforming voltage' is not a required characteristic of a 'transformer'. ... and, even more off-topic ...

Same was a Vista is a device operating system so could be called DOS but we all know DOS is seen to mean command line interface (CLI).

When I was shorter in the tooth, it meant "Disk Operating System" - and, of course, in those days there were no 'interfaces' other than 'command line' ones!

Kind Regards, John

 

[Sam Gangee]

Correct but reason I said tordional transformer

... is that you can't spell "toroidal"?
Or did you mean "torsional"? (Unlikely)