GU10 LED lamp on 12V Driver Transformer possibility

RF Lighting said:

No they are not. I've lit literally hundreds of rooms with them.

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Presumably by using several thousand of them?

You and I disagree.

You think that taking a light which was not designed to light up rooms, and using it to do that, is OK. I think it is wrong.

You think that taking a light which was designed to have characteristics which make it unsuitable for general room illumination, and installing it in multiples to try and work around the shortcomings intrinsic to its design is OK. I think it is wrong.

pmc64 said:

Thanks John. I was referring to this type of lamp but without the inbuilt "capacitive dropper or switch mode driver" (Thanks Winston)

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I realise that, so I'm still a bit confused. 12V LED GU10s, like the example I linked to, will not have any of that inbuilt electronics , since they are designed to work directly from a 12V source, supplied by an external 12V 'transformer' or power supply. They only need those inbuilt electronics if they are designed to work directly from 230V mains.

pmc64 said:

But I like the connectivity of the GU10 twist fit better, but they all want a mains feed without tranny because they have their own step down bits in the lamp itself.

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See above. 12V ones like the example I linked to do not have those step-down bits.

pmc64 said:

So I suppose I'd need a 12V GU10 LED (without step down tech) that can work in conjunction with a separate 12v tranny.

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Exactly - and the example I linked to is one such lamp.

pmc64 said:

Or what would happen if you put a 12v lamp (with step down) after a 12V tranny?

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I can't see that there can be such a thing as a "12V lamp (with step down)". If it has the 'step down' electronics, that's because it's designed to work from 230V, not 12V. Trying to run an LED lamp 'with step down' after a 12V transformer would not work, since it would only be getting 12V, not the 230V it needed.

pmc64 said:

Hope that makes sense...

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Not totally Is it me that is misunderstanding something?

Kind Regards, John

If you lads haven't come across this type of bulb set up, then I suppose I'll have to use the push fits...

Any recommendations for 12v LED down lights, Both tranny and lamps thanks.

Don't want to end up with these!
http://www.youtube.com/watch?v=x7SaLgDsYVk

OK

My bad. Apologies John, I presumed that had the built in components, plus my posts are lagging behind. Thanks.

pmc64 said:

My bad. Apologies John, I presumed that had the built in components, plus my posts are lagging behind. Thanks.

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As I said, if it's described as a 12V LED (GU10 or otherwise), then it will have none of those inbuilt components - which, when present, are there only to reduce the voltage from 230V to whatever the LEDs in the lamp need.

Kind Regards, John

The site you kindly linked to john is impossible to get to a purchase point. Keeps throwing me to tesco win £500 and other non starters.

Do you have another link I could use mate, as my searches for 12v GU10 LED lamp doesn't return anything of use! Sorry to be a pain.

I must say I am having the same trouble finding them.

What did you enter in the search bar, John?

EFLImpudence said:

I must say I am having the same trouble finding them. ... What did you enter in the search bar, John?

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Ah!! TBH, I can't remember what I searched for - I'm off to do some experiments - watch this space.

Kind Regards, John

1) Although I am sure you will find 12 volt LED GU10 bulbs they are clearly not as easy to source as GU5.3 bulbs and to use non standard bulbs is asking for problems.

2) Although the pins of a GU5.3 bulb with 50W or 4A seem to fail with 0.8A there is really no problem.

3) The LED low voltage bulb has a wide voltage range typically 150 to 250 volt with the internal circuit taking care of any volt drop. However the extra low voltage LED bulb seems to have in the main no data published other than being 12 volt. Some may still have built in circuits to cater for a voltage range but often it's hard to even get info as to if DC or AC or both can be used.

4) All LED's require current control not voltage and some driver converts a set voltage to a set current this could be a simple resistor or a full switch mode power supply so be it extra low voltage 12 volt or low voltage 230 volt there will still be some internal circuitry.

5) An AC power supply gives a RMS value listed at 12 volt but the peak value may be well over 12 volt with a sin wave 17 volt with non sin wave may be much higher. These voltages may damage the bulb so only real way is to use a DC power supply.

6) Many power supplies both AC and DC use the switch mode method of control which often means there is both a min and max current. Often using LED bulbs means the min current is not reached.

So the GU10 has one clear advantage in that one does not need to remove any bevel to renew the bulb. The GU5.3 however needs some form of retention other than the bayonet fitting.

The 230 volt (low voltage) fitting has the advantage of no need to have a matched extra low voltage power supply and can accept a wide range of voltages. The 12 volt (extra low voltage) has the advantage of being able to be used in special locations like bathrooms.

The lighting industry has coined many names which would not be used by the rest of the electrical trade. And have also adopted advertising methods which would also not be used with the rest of the electrical trade.

a) They call an AC power supply using electronic control a "Transformer" rest of the trade would only refer to the induction between to coils as a transformer if there are other components we would call it a power supply.

b) They advertise bulbs without declaring the voltage they require like GU10 and MR16 and assume you think GU10 = 230 volt and MR16 = 12 volt even when neither is true.

c) They call a DC power supply a driver even when it's voltage which is regulated the rest of the trade consider drivers to be current regulating devices.

d) The same applies to phrases like ballast most would consider these to be a coil of wire another name for a choke but the lighting industry also includes electronic units which replace the traditional ballast.

We even see phrases like three way switching where it is two way with an intermediate. So one has to be very careful at best of times to select the correct product.

So although you could get a 12 volt GU10 MR16 LED bulb to use them would be asking for problems.

The 50mm spot light has some very real problems. In the main it relies on reflecting the light off white surfaces. And so often the floor is not white. My son has 6 GU10 fittings in the kitchen with a massive 42 Watt but the living room has just two pendent fittings with 14 watt total and is 6 times the area of the kitchen.

To be fair the total cost per year of all lighting in his house if left on 24/7 would be £42 so although it may be a pour system of lighting the kitchen does it really matter? It looks good and gives enough light although I will admit yesterday helping him I was using my cycle head lamp to help him see the boiler controls in the kitchen.

My bedroom is the same. There are 4 GU10 lamps and one CFL so a total of 23W just for a bedroom which is really OTT. 4 x 3W and 1 x 11W. But do I really care at 23W when for years I used 60W in a bedroom I really don't care. Plus I do have three switches so 3W, 6W, 17W, 20W or 23W options depending on which lamps are switched on.

But buying 3 x 3W GU10 lamps for £7 is cheap enough. All are 230 volt. Try getting odd voltages or sizes increases the cost no end. The quartz tungsten halogen 12 volt GU10 I linked to was £3 each. With a 230 volt version you would get 3 for a £1. With LED the price sores anyway 3 x 3W LEDs can cost £7 at 230 volt at 12 volt the specials would likely cost £20 each and as a result is just does not make sense to go for 12 volt GU10's even if you can find a supplier.

Should one of my GU10 LED lamps blow I can jump on the bus and buy a replacement and fit in within an hour. With 12 volt GU10 you are looking at 7 days to get replacement. At with LED lamps lasting for so long keeping spares does not really make much sense.

Thanks Eric...Wow! that was a lesson. Looks like the purpose of the 2 different connectors are also a visual to stop any blown lamps in particular if you did have a GU10 type specifically made for use with 12v driver transformer use (without step down circuitry inbuilt) that would blow if unknowingly replacing in the mains fed set- up. Although the twist fits are more robust and reliable. It's a pity they don't make a better connection than the 2 pin push though.

I suppose a caravan or boat supplies may have them.

But as it stands, it looks as if push pins are the way to go in my case...Thanks.

Nothing wrong with 5.3mm push in connections, only time they sometimes fail is with the heat from a 50 watt halogen, you wont have this problem with LED

333rocky333 said:

Nothing wrong with 5.3mm push in connections, only time they sometimes fail is with the heat from a 50 watt halogen, you wont have this problem with LED

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Thanks Rocky. That's eased my mind a lot.

As you may be aware that sometimes you have to fiddle with the lamp holder or give it a tap on some finicky holders when they start messing up.

Suppose a cheap replacement is the answer, but for some reason you never get round to doing it...

If you have concerns, there is whats known as a universal lampholders
These are for G4 and G5.3 lamps.
Difference being the spring contacts have more pressure to grip down on the thinner G4 pins.

However with led the cheaper G5.3 branded ones should suffice, though if your old ones are suspect prior to led, then its prudent to swop them anyway.

Another thing with 12 volt led is lamp/ transformer compatibility which still seems to be dubious

Another option if your only talking about a few fittings, you could splash out for integrated fitting where the unit has lamp permanently wired into the fitting

Thanks...Handy little site for lamp holders...

http://www.intl-lighttech.com/products/light-sources/lamp-holders?field_base_types_tid=154&page=1