It's that time again: LED bulbs - recommendations?

I'm currently using cheapy LED GU10s in the bathroom, they're not used a huge amount but are dying every few months. I'm after something that'll last longer but won't break the bank, the cheap ones are ~ £1.70 each so I need to consider an expensive bulb vs 3 or 4 cheap ones long term.

Any suggestions? I'm trying to buy from Amazon as I have a load of credit on there but all I can mostly find is fakes or non-branded ones.

I'm needing ~4W GU10s, bright white, short length if possible.

Cheers folks!

Rob

Interested in this as well. Currently on 'full fat' bulbs in the bathroom (12V) and other rooms (240V). Would love to pull them all out tbh, but changing to LEDs is going to be the best short to mid term solution.

Get MR16s. They don't die like GU10s do, although they take a tiny bit more work to install the separate 12v power source.

Have binned all our GU10s - complete waste of money.

I went gu10 after having issues with mr16s, plus when I looked the led mr16s were a lot pricier. I'd rather not change it all over again so it's gu10 for the foreseeable future :)

These from screwfix http://www.screwfix.com/p/lap-gu10-l...ack-of-5/3797g

I have relamped the 11 Kitchen ccfl's and 4 bathroom 50w full fats.

The bathrooms the same and I swapped out quality Aurora 50w Halogens. The Kitchens like blackpool illuminations now!

My father in laws done about 20 and had 2 blow out the box and 1 soon after so he had a bad box but everyones got a screwfix close by so he got them swapped and since then all is good.

How are they for light? I can't see from the pic but it looks like the LEDs are covered with a white filter/cap?

What's your budget ? I normally get these. Not had any blow yet.
http://www.ledhut.co.uk/spot-lights/...net-price.html

I have a lot of MR16s in the kitchen, and have swapped to the new LED bulb range that Tesco of all places are now stocking. I think they are £6.50 a bulb, but they don't seem to require re-wiring the ceiling with expensive special LED transformers and so far none of the bulbs have died prematurely (I have 12 of them, ranging from a couple of months old to a couple of weeks old).

They have all sorts in the range, which come in blister packs.

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Originally Posted by Rob_B

How are they for light? I can't see from the pic but it looks like the LEDs are covered with a white filter/cap?

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its a lens to give it the required angle, as bright if not brighter than a standard 50w

Quote:

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Originally Posted by Phage

What's your budget ? I normally get these. Not had any blow yet.
http://www.ledhut.co.uk/spot-lights/...net-price.html

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Heard good things about LEDhut but not heard of lumilife.

Found these
http://www.amazon.co.uk/Lumilife-3-8...=AZGYNAMS2M097

But can buy 3.7 cheapo ones for the same price, assuming cheapos last 6 months that's getting close to even :/

I replaced about 40 MR16 halogens with GU10 LEDs earlier this year, I simply replaced the transformers and MR16 holders with GU10 holders.

After my own testing of about a dozen different LED bulbs I settled on these two:

About 30 of these:

http://www.amazon.co.uk/gp/product/B...ilpage_o07_s00

and about 10 of these:

http://www.maplin.co.uk/p/verbatim-4...led-gu10-n49qf

Since installing them in April I've not had a single failure.

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Originally Posted by DanceswithUnix

I have a lot of MR16s in the kitchen, and have swapped to the new LED bulb range that Tesco of all places are now stocking. I think they are £6.50 a bulb, but they don't seem to require re-wiring the ceiling with expensive special LED transformers and so far none of the bulbs have died prematurely (I have 12 of them, ranging from a couple of months old to a couple of weeks old).

They have all sorts in the range, which come in blister packs.

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I've used individual transformers in the kitchen when I redid it, but in the bathroom I just used a single LED transformer to drive all the downlights. Since MR16s are very simple and don't have quite the risk of badly wired trasformers lurking inside the housing, I mostly just use cheapy LEDs direct from HK or Singapore paired with a European transformer.

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Originally Posted by wasabi

Since MR16s are very simple and don't have quite the risk of badly wired trasformers lurking inside the housing

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That's not true.

Both GU10 and MR16 LED lamps use the same voltage conversion methods and have similar components, they just work at different input voltages.

Quote:

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Originally Posted by DDY

That's not true.

Both GU10 and MR16 LED lamps use the same voltage conversion methods and have similar components, they just work at different input voltages.

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Why would you convert 12v to 12v?

Quote:

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Originally Posted by Rob_B

Heard good things about LEDhut but not heard of lumilife.

Found these
http://www.amazon.co.uk/Lumilife-3-8...=AZGYNAMS2M097

But can buy 3.7 cheapo ones for the same price, assuming cheapos last 6 months that's getting close to even :/

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True, but with the ones I linked to there's no re-wiring, no transfomer and no blow-outs.

GU10 and MR16 refer to the connections. GU10 are typically used on 230V (mains voltage) and for LED lamps have integral voltage conversion and current limiting to operate Light Emitting diodes correctly (they need a constant current supply)

MR16 are used on 12 volt supplies from an external transformer. Again on an LED lamp, the LEDS still need a constant current source which is incorporated within the lamp housing (and in both cases may be incorporated in the LED die itself). They may also have voltage conversion, although it is probably unnecessary.

However, the voltage conversion for an intrinsically low voltage lamp is simpler as the transformer (or SMPS) is external to the lamp body, while a native 230V lamp has it internally, and the larger voltage drop implies more heat to remove, and potentially a bulkier design, although at the low currents involved, the power dissipation is considerably reduced, which is why they can be built into the lamp body, and use low power SMPS.

You can power an LED off mains directly, with a simple diode and resistor which gives a more or less constant current, but it is inefficient, and with the LEDs used for lighting, operating the upper edge of the operating envelope, not very satisfactory because mains voltage itself is relatively poorly regulated (by the standards required for electronic equipment)

Hi risk areas (in terms of the IET wiring regulations) such as bathrooms require the use of 12 volt lamps so the primary voltage conversion can be done outside the room, and that is true for LED and halogen lamps. In other locations, 230V lamps are an acceptable plug in replacement for conventioal halogen lamps.

Quote:

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Originally Posted by Phage

What's your budget ? I normally get these. Not had any blow yet.
http://www.ledhut.co.uk/spot-lights/...net-price.html

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Do they have a glass on the front? If not those are potentially pretty dangerous. Cheap ones often only have the power circuitry on one leg, so those solder terminals on the face have potential to be at mains voltage (boom boom!)

Quote:

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Originally Posted by wasabi

Why would you convert 12v to 12v?

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LEDs themselves don't run at 12V, depending on the LED configuration the voltage can be stepped down or even up. I've not done detailed tear downs, but I've always noticed inductors and various ICs in both the GU10 and MR16 LED bulbs I've trialled and taken apart suggesting some form of switching conversion.

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Originally Posted by DDY

LEDs themselves don't run at 12V, depending on the LED configuration the voltage can be stepped down or even up. I've not done detailed tear downs, but I've always noticed inductors and various ICs in both the GU10 and MR16 LED bulbs I've trialled and taken apart suggesting some form of switching conversion.

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Any failed GU10 I've taken apart lights right up at normal brightness when you hook up the simplest last leg of the circuit (cathode and anode) to a 12v battery. Suspect many of them have some kind of polarity checker given the simple 2 pin thing going on in both GU10s and MR16s. And maybe a capacitor to smooth the delivery and a heatsink/fan on the higher wattage units. Or flashy dimmers / colour changers. None of it needed really though in simplest form.

Never had an MR16 fail, only had 3 GU10s out of dozens last for multiple years (cheapy Lidl ones strangely, suspect due to low 1.8 wattage, and intermittent usage in porch).

Never personally encountered consumer LED lights that don't natively want to run at 12v. I've dabbled with LEDs in the home / aquarium / electric bike / shed and car for years now.

Rob.

In hope my electrical work is OK. ;)

Led hut is great for lamps. In use them all in my house.

I use these GU10s - http://www.ledhut.co.uk/spot-lights/...eam-angle.html

The all come with a 5 year warrenty. If the fail, the company will replace.

I reckon the workmanship is up to scratch Chris ;)

Amazon reviews for the bulbs I have suggest they do go easily, I've seen those ones on Amazon Chris, wasn't sure if the beam would be too focused, guess I didn't read the description! (30% off LEDHUT at the moment too :))

Ended up with 5 of these for £27.12
http://www.ledhut.co.uk/spot-lights/...50-lumens.html

That's with 30% off + there is 20% quidco (about a fiver) to come :)

Fingers crossed these ones last!

Quote:

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Originally Posted by wasabi

I've used individual transformers in the kitchen when I redid it, but in the bathroom I just used a single LED transformer to drive all the downlights. Since MR16s are very simple and don't have quite the risk of badly wired trasformers lurking inside the housing, I mostly just use cheapy LEDs direct from HK or Singapore paired with a European transformer.

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I have 18 lamps in the kitchen (it is an odd L shape) and frankly really didn't want to re-wire a single bulb.

These seem to work fine with the old constant voltage transformers.

Will be a while before I find out if the 15 year lifespan is reduced.

Quote:

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Originally Posted by wasabi

Any failed GU10 I've taken apart lights right up at normal brightness when you hook up the simplest last leg of the circuit (cathode and anode) to a 12v battery. Suspect many of them have some kind of polarity checker given the simple 2 pin thing going on in both GU10s and MR16s. And maybe a capacitor to smooth the delivery and a heatsink/fan on the higher wattage units. Or flashy dimmers / colour changers. None of it needed really though in simplest form.

Never had an MR16 fail, only had 3 GU10s out of dozens last for multiple years (cheapy Lidl ones strangely, suspect due to low 1.8 wattage, and intermittent usage in porch).

Never personally encountered consumer LED lights that don't natively want to run at 12v. I've dabbled with LEDs in the home / aquarium / electric bike / shed and car for years now.

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It's not uncommon for lower wattage LED systems to use resistors for current limiting and can be on die as mentioned by PeterB. Hence, you can stick a good few volts at without worrying about the current across these LEDs.

However, high power and high efficiency LED systems are unlikely to use resistors for current limiting because they ruin efficiency and dump heat where you don't want it. For these, sticking 12V or any other voltage that's not constant current can be a bad idea.

Now that I've mentioned high power LEDs, now's a good time for a gratuitous show-off of my current project, a portable 100W lipo powered LED torch. I'll be testing it outdoors soon, will post pics when I do.

Quoted 7500lm of light with a tested battery life of around 70 minutes. Body crudely designed and 3D printed by myself, any resemblance to an 80s sci-fi prop is coincidental.

http://img.photobucket.com/albums/v6...h__DSC3241.jpg http://img.photobucket.com/albums/v6...h__DSC3242.jpg http://img.photobucket.com/albums/v6...h__DSC3243.jpg http://img.photobucket.com/albums/v6...h__DSC3248.jpg http://img.photobucket.com/albums/v6...h__DSC3245.jpg

More info once I get the outdoor tests done.

I'm fairly clued up about LED lights these days so want to dispel a few points:

All commercially available LED's that I've seen either run at 12V or 24V
You cannot run LED's off mains (230/240V) without some form of transformer stepping down the voltage to the required level. Typically 12V.
The step down in voltage is often within the housing of the GU10 bulbs you get so they can be directly fitted into existing systems
GU10 and GU5.3 (or MR16 as people are referring to them here) refers to the pin connection type on the back, MR16 is the reflector (housing) size...see here: http://en.wikipedia.org/wiki/Multifaceted_reflector

LEDHut are a good internet supplier, but you can also try V-TAC (london based importer). If you're doing a full re-wiring setup you can see if Sunpower UK (Reading based) will supply you with the Transformers (LED transformer specialists).

From what I've seen Philips would be the brand to go with for high end.

Just some notes regarding LED:

LED are very voltage sensitive. If the wiring in your house isn't providing a highly stable voltage this could be the cause of them burning out. I'd recommend reading these 2 articles if you want to know more:

http://www.digikey.com/en/articles/t...t-power-supply
http://www.amperor.com/products/led/...ed_driver.html

To try and simplify the explanations in the below links LED have an activation voltage (they aren't linear like traditional bulbs where doubling the voltage would double the power and therefore ~ 2x the brightness). What this means is upto 11.9V lets say, you will see no effect at all, then at a certain voltage you will see the LED activate, apply more voltage and it will get brighter, but this will reduce the life expectancy (thus they have an optimal voltage they should be run at).

As the LED heats up it actually requires LESS voltage to push the same current through the circuit, unfortunately it also becomes less efficient at producing light as it warms up. The second point has a greater overall bearing on performance when both factors are taken into consideration, so LEDs run more efficiently (less power needed) when cool, hence high powered LED have metal heat sinks to dissipate the heat build up.

The voltage they operate at is VERY sensitive. For example if we look at these two graphs:

http://www.digikey.com/en/articles/t..._How_Fig_2.jpg http://www.digikey.com/en/articles/t..._How_Fig_3.jpg

3V produces 1 amp = 400 lumen approx.
3.2V produces 1.8 amp = 700 lumen approx.

...a 0.2V increase nearly doubles the light output! Hence a voltage stable system is required to stop early bulb failure.

This sensitivity to voltage is also the reason you can only put so many in series before the ones on the fair end of the setup simply stop lighting. This is due to V drop over the length of the circuit. If you imagine you have a 12V circuit. You'd expect 12V LED bulbs to work on it (and they will, but only upto a limited number). If you think of it this way, every light in the circuit reduces the voltage for the next light in the series. So the first bulb receives the full 12V, the second maybe 11.95V, the third 11.9V and so on. This is known as V drop and happens as resistance (LED bulbs in this case) build up. I've already explained that LED are highly voltage dependent, so eventually you reach a situation where the V drop is too great and the voltage the circuit is supplying to the end bulbs doesn't reach the actiation voltage required.

My final point would be with regards to the transformers. You can get CC (constant current) or CV (constant voltage). The articles above explain the difference. But in a nutshell CV are "dumb" transformers stepping down the mains voltage to the voltage they're designed to do...typically 12V or 24V. They also have a maximum rated wattage (like PC power supplies, no difference there). In fact PC power supplies can be used for 12V LED systems, as they provide 12V outputs :)

CC have feedback systems which vary the voltage to maintain a constant current. Now I know we talk about LED in terms of voltage, but technically this is wrong, they should be rated at an optimal current. It's just that voltage is a term people are more familiar with so manufactures use that, confusingly. If we accept LED's should run at a rated current, you can now see why a constant current transformer would be a good thing! CC transformers will vary the voltage to ensure constant current at different operating temperatures, maximising the life span of the LED bulbs and ensuring they are not over powered and "burnt out".

Having said this, most setups use constant voltage systems as it's "good enough" and cheaper to buy.

Quote:

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Originally Posted by Rob_B

Ended up with 5 of these for £27.12
http://www.ledhut.co.uk/spot-lights/...50-lumens.html

That's with 30% off + there is 20% quidco (about a fiver) to come :)

Fingers crossed these ones last!

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Good choice.

If they fail within the warranty period, the will be replaced gratis.

The ones I linked to in previous post are these one I have and look like this in my kitchen. Very bright

https://www.dropbox.com/s/4dt9et211j...24148.jpg?dl=0

Looks good, I went for the 120 degree ones, as you've seen our bathroom is tiny so not sure why I did that but oh well it's done now!

Can't get away with cool whites in the kitchen, looks far too bright, maybe when I get around to changing the counter top it might look better but for now I'll stick with the cheapy 'warm' SMDs I've got.

The 120 deg are the ones i have and they are very good. Nice spread of light.

Merry Christmas to everyone by the way.

Quote:

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Originally Posted by herulach

Do they have a glass on the front? If not those are potentially pretty dangerous. Cheap ones often only have the power circuitry on one leg, so those solder terminals on the face have potential to be at mains voltage (boom boom!)

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Yes of course they do

Quote:

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Originally Posted by cptwhite_uk

I'm fairly clued up about LED lights these days so want to dispel a few points:

All commercially available LED's that I've seen either run at 12V or 24V
You cannot run LED's off mains (230/240V) without some form of transformer stepping down the voltage to the required level. Typically 12V.
The step down in voltage is often within the housing of the GU10 bulbs you get so they can be directly fitted into existing systems
GU10 and GU5.3 (or MR16 as people are referring to them here) refers to the pin connection type on the back, MR16 is the reflector (housing) size...see here: http://en.wikipedia.org/wiki/Multifaceted_reflector

LEDHut are a good internet supplier, but you can also try V-TAC (london based importer). If you're doing a full re-wiring setup you can see if Sunpower UK (Reading based) will supply you with the Transformers (LED transformer specialists).

From what I've seen Philips would be the brand to go with for high end.

Just some notes regarding LED:

LED are very voltage sensitive. If the wiring in your house isn't providing a highly stable voltage this could be the cause of them burning out. I'd recommend reading these 2 articles if you want to know more:

http://www.digikey.com/en/articles/t...t-power-supply
http://www.amperor.com/products/led/...ed_driver.html

To try and simplify the explanations in the below links LED have an activation voltage (they aren't linear like traditional bulbs where doubling the voltage would double the power and therefore ~ 2x the brightness). What this means is upto 11.9V lets say, you will see no effect at all, then at a certain voltage you will see the LED activate, apply more voltage and it will get brighter, but this will reduce the life expectancy (thus they have an optimal voltage they should be run at).

As the LED heats up it actually requires LESS voltage to push the same current through the circuit, unfortunately it also becomes less efficient at producing light as it warms up. The second point has a greater overall bearing on performance when both factors are taken into consideration, so LEDs run more efficiently (less power needed) when cool, hence high powered LED have metal heat sinks to dissipate the heat build up.

The voltage they operate at is VERY sensitive. For example if we look at these two graphs:

http://www.digikey.com/en/articles/t..._How_Fig_2.jpg http://www.digikey.com/en/articles/t..._How_Fig_3.jpg

3V produces 1 amp = 400 lumen approx.
3.2V produces 1.8 amp = 700 lumen approx.

...a 0.2V increase nearly doubles the light output! Hence a voltage stable system is required to stop early bulb failure.

This sensitivity to voltage is also the reason you can only put so many in series before the ones on the fair end of the setup simply stop lighting. This is due to V drop over the length of the circuit. If you imagine you have a 12V circuit. You'd expect 12V LED bulbs to work on it (and they will, but only upto a limited number). If you think of it this way, every light in the circuit reduces the voltage for the next light in the series. So the first bulb receives the full 12V, the second maybe 11.95V, the third 11.9V and so on. This is known as V drop and happens as resistance (LED bulbs in this case) build up. I've already explained that LED are highly voltage dependent, so eventually you reach a situation where the V drop is too great and the voltage the circuit is supplying to the end bulbs doesn't reach the actiation voltage required.

My final point would be with regards to the transformers. You can get CC (constant current) or CV (constant voltage). The articles above explain the difference. But in a nutshell CV are "dumb" transformers stepping down the mains voltage to the voltage they're designed to do...typically 12V or 24V. They also have a maximum rated wattage (like PC power supplies, no difference there). In fact PC power supplies can be used for 12V LED systems, as they provide 12V outputs :)

CC have feedback systems which vary the voltage to maintain a constant current. Now I know we talk about LED in terms of voltage, but technically this is wrong, they should be rated at an optimal current. It's just that voltage is a term people are more familiar with so manufactures use that, confusingly. If we accept LED's should run at a rated current, you can now see why a constant current transformer would be a good thing! CC transformers will vary the voltage to ensure constant current at different operating temperatures, maximising the life span of the LED bulbs and ensuring they are not over powered and "burnt out".

Having said this, most setups use constant voltage systems as it's "good enough" and cheaper to buy.

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While I wouldn't disagree in principle with that, an LED operating voltage is 2.4 volts (as the graphs show) not 12 volts, and so any LED lamp that runs off any voltage above that voltage needs some form of regulation.

But it is slightly more complicated than that. An LED is no different electrically from any other diode. It has a maximum reverse breakdown voltage, a maximum reverse current, a forward voltage drop and a maximum forward current. An LED forward voltage drop is, as stated, 2.4 volts, and when that is reached, the forward resistance is very low, and so the current has to be limited by other means, hence a constant currant source.

You can run an LED cut at any voltage above 2.4 volts by running it in series with a resistor, which is what you do for an LED indicator or panel light. The resistor, combined with a steady DC voltage forms the constant current source. If the LED is shorted out, the current drawn through the resistor will not change.

Most LED lamps for general purpose illumination consist of arrays of LED elements, each one has to be fed with a constant current. The challenges depend on the source supply for the array, 12 or 230, AC or DC, and providing that supply as efficiently as possible.

Quote:

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Originally Posted by cptwhite_uk

This sensitivity to voltage is also the reason you can only put so many in series before the ones on the fair end of the setup simply stop lighting. This is due to V drop over the length of the circuit. If you imagine you have a 12V circuit. You'd expect 12V LED bulbs to work on it (and they will, but only upto a limited number). If you think of it this way, every light in the circuit reduces the voltage for the next light in the series. So the first bulb receives the full 12V, the second maybe 11.95V, the third 11.9V and so on. This is known as V drop and happens as resistance (LED bulbs in this case) build up. I've already explained that LED are highly voltage dependent, so eventually you reach a situation where the V drop is too great and the voltage the circuit is supplying to the end bulbs doesn't reach the actiation voltage required.

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That's not quite how diode voltage drop works. If you put a load of diodes in series, each diode will need a potential equal to or greater than its Vf in order to pass current and light. If you put a multimeter in volt mode across an LED, you'll measure the voltage drop across it, which provided it's lit will be around its Vf i.e. something like 3.2V. Add up the voltage across each diode and you end up with the supply voltage, minus any resistive drop in the cables, drop resistors, etc. This is why for '12v' chains, you'll generally have three LEDs in series along with a resistor which is chosen based on desired current, any more than that and you'll find there are simply more chains of three added in parallel. If you try adding more diodes so the combined forward voltage is greater than the supply voltage, you'll reach a point where they'll just stop conducting and the whole chain will not light.

If you start adding larger numbers of diodes to each chain, you can run into problems with the variability of Vdrop resulting in significantly uneven power to the LEDs, which in turn will shorten lifespan.

This is more of an immediate problem when trying to run LEDs directly in parallel however - unless you select them with closely matched Vf, they can be a nightmare to control. E.g. in order to power one with a higher Vf efficiently, you might be over-driving the other and vice-versa. So you end up with different current, and therefore power, flowing to each LED.

Voltage then isn't just a throwaway term when it comes to LEDs at all, it's quite an important metric when e.g. designing driver circuits, matching them to run in circuit, etc, just like it's important for any diode. Current and voltage aren't interchangeable so you need to know both when designing drivers. E.g. it's no good designing a CC driver for a chain if its output voltage is lower than the combined Vf of the diodes.

Quote:

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Originally Posted by cptwhite_uk

My final point would be with regards to the transformers. You can get CC (constant current) or CV (constant voltage). The articles above explain the difference. But in a nutshell CV are "dumb" transformers stepping down the mains voltage to the voltage they're designed to do...typically 12V or 24V. They also have a maximum rated wattage (like PC power supplies, no difference there). In fact PC power supplies can be used for 12V LED systems, as they provide 12V outputs :)

CC have feedback systems which vary the voltage to maintain a constant current. Now I know we talk about LED in terms of voltage, but technically this is wrong, they should be rated at an optimal current. It's just that voltage is a term people are more familiar with so manufactures use that, confusingly. If we accept LED's should run at a rated current, you can now see why a constant current transformer would be a good thing! CC transformers will vary the voltage to ensure constant current at different operating temperatures, maximising the life span of the LED bulbs and ensuring they are not over powered and "burnt out".

Having said this, most setups use constant voltage systems as it's "good enough" and cheaper to buy.

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For powering a single LED/series chain, a CV/CC supply would be ideal as it would both limit no-load voltage and prevent thermal runaway killing diodes. However, CC isn't without its problems - speaking in terms of a lighting transformer supplying multiple spotlights for instance, it would be near useless unless you had one for every lamp, and even then you'd be very limited to what lamps would be compatible.

E.g. imagine your bathroom has an LED CC supply for say 3 spots, supplying say 1.5A if each lamp wants 500mA. What happens when a lamp fails or is removed? The other two share that 1.5A between them, 750mA each, and probably go pop, or if its supply voltage is close to the ideal voltage anyway, you essentially just end up back with with a CV supply. You're also pretty much wasting your time using a CC supply for >1 series chain anyway because of the variability mentioned earlier; you can potentially still end up with one chain hitting thermal runaway without the CC regulator reacting.

Just received and fitted them, wow they're bright, I know my previous ones were 4W and these are 4.5 but the difference is unreal!

I have bought the amazon ones before and they have been very good. only had one or two failures in the 2 years I have had them.

Just spotted your reply watercooled, thanks for the info!

maplin do some good ones got a G9 for £1

DDY, these inductors are there to limit the amount of current that can flow through as soon as the LEDs are turned on. The ICs regulate the power going to these LEDs. Although, they generally have some externally connected or inbuilt resistance to limit the amount of current flow but there is generally a huge pulse of current in which case an inductor works are a solenoid. The inductance of the inductor is selected very carefully for such purposes.

pcb assembly

Quote:

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Originally Posted by roberto89

DDY, these inductors are there to limit the amount of current that can flow through as soon as the LEDs are turned on. The ICs regulate the power going to these LEDs. Although, they generally have some externally connected or inbuilt resistance to limit the amount of current flow but there is generally a huge pulse of current in which case an inductor works are a solenoid. The inductance of the inductor is selected very carefully for such purposes.

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Actually, the inductor will be part of a switched mode power supply built into the lamp. The power regulation needs to be as efficient as possible else you will lose more power there than the LEDs use and overall efficiency becomes rubbish (and you have more heat to get rid of). Switched mode regulators mean inductors.

You only get current inrush is there is a cold element to heat or a big capacitor to charge. Neither applies here.

What is your budget? Most of the lights on Amazon are still guaranteed, but the life of energy-saving lamps is not very long.
You can choose more brands to compare, I hope to help you.

Necro post......

Anyway my own 2p on this

I can only really recommend 2 brands - Philips (well duh) and when they made them the Ikea GU 10 LEDS.

I've tried a number of other brands (LAMP / odd ball brands on amazon) and never been impressed with the quality of build or the light given out.

Still a bunch of halogen lights to cycle out but they are proving to be longer lasting but i guess that's because they are the least used in the house (unlike the hall wall and kitchen lights which i swapped out like 3+ years ago )

Used to be a fan a Phillips, also Samsung are a good brand as they did a bulb that could run off AC 12v when I converted some IKEA 12v halogen wire lights that had an AC transformer.

I have osram to replace my normal lights and Screwfix for my GU10 in the bathroom and kitchen

Sent from my SM-G920F using Tapatalk

Homebase do a good brand of bulb. TCP or something along those lines.
My other brand is Ikea though if what Apex says is true I'm gutted. They were the best I've ever had for GU10

I will say if anyone lives near a Clas Ohlson to check out their shop, they have a myriad of bulbs on display. Because they are all housed in their own box it gives you a good indication as to the light you will get as you can see the reflection on the sides etc. Very good setup for bulb shopping. Most shops will have bulbs on display but next to other bulbs or just in the open, it makes it hard to judge the type of light to expect. I find the lumens and k rating to be pointless.

P.S. was wondering why people were recommending Maplin then realised this is way back in 2015 hah

You would be hard pushed to find a Homebase these days.

I tend to use Lumilife lamps from Led hut (www.ledhut.co.uk) or B&Q own brand.

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Originally Posted by AGTDenton

Homebase do a good brand of bulb. TCP or something along those lines.
My other brand is Ikea though if what Apex says is true I'm gutted. They were the best I've ever had for GU10

I will say if anyone lives near a Clas Ohlson to check out their shop, they have a myriad of bulbs on display. Because they are all housed in their own box it gives you a good indication as to the light you will get as you can see the reflection on the sides etc. Very good setup for bulb shopping. Most shops will have bulbs on display but next to other bulbs or just in the open, it makes it hard to judge the type of light to expect. I find the lumens and k rating to be pointless.

P.S. was wondering why people were recommending Maplin then realised this is way back in 2015 hah

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Just checked and Ikea still do the GU10's but they look to have changed supplier so they arn't the same, for the price i paid i am well happy with them and they are close to the 2700k the box said they where; the new ones i carn't comment on.

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Originally Posted by peterb

You would be hard pushed to find a Homebase these days.

I tend to use Lumilife lamps from Led hut (www.ledhut.co.uk) or B&Q own brand.

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Have bought from there I've been less then impressed with the light from them, even the 2700k ones seem more like daylight 3000k + and a few of them have failed very quickly.

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Originally Posted by Apex

Have bought from there I've been less then impressed with the light from them, even the 2700k ones seem more like daylight 3000k + and a few of them have failed very quickly.

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Hmm - not my experience at all - I have some MR16 and GU10lamps that are over 5 years old and still seem OK. If you are using 12v lamps it is important to use a proper electronic ballast - transformers for 12v halogen tens to have poor regulation,

Hmm, I thought I'd already mentioned this but it must have been in another thread: I've found Diall brand LED bulbs from B&Q are decent; good colour temp, seemingly decent CRI (not actually tested but colours seem OK under them), no perceptible flicker, etc.

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Originally Posted by peterb

I tend to use Lumilife lamps from Led hut (www.ledhut.co.uk)

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Same here.
Plus a whole bunch of folk on some professional workshop forums. No problems so far... Most of us are using their fittings too, though, in case that matters?

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Originally Posted by peterb

You would be hard pushed to find a Homebase these days.

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Ah I still have 2 near me. Hadn't realise they were suffering but actually looks pretty dire!

I've used a couple of sainsburys own brand LED bulbs, and haven't had one fail yet. The clear ones make a pretty good stand in for incandescent/halogen bulbs in exposed fittings (only noticeable difference is they take a fraction of a second longer to turn on than halogens, but it's pretty hard to spot unless you look for it)

That does at least suggest they have a proper driver circuit rather than the cheap+nasty method of capacitive dropper or just stringing a load together and hoping for the best (they flicker horribly and don't generally last very long).

Hi!
I found these variants [**snip**]. I want to buy some for my garden and make garlands. They will arrive in two days and I will give better review :)


URL removed by Admin.

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Originally Posted by Apex

Just checked and Ikea still do the GU10's but they look to have changed supplier so they arn't the same, for the price i paid i am well happy with them and they are close to the 2700k the box said they where; the new ones i carn't comment on.

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You are right, they have changed.
So I used to get the 3w frosted bulb. They're now 2.5w and unfrosted. Annoyingly they put it under the same brand name, yet its different.
I will say £3 for 3 bulbs is mighty good value, so I was happy to take the gamble.
But it's no where near as good light, I suspect more to the frosting. Looks like I am back to the drawing board as well with the GU10s

For all those who have LED bulbs that don't last long, check your mains voltage, they are designed to use the Euro standard 230v, although the UK signed up to this the power distribution companies are still running at 240. Now if you have a solar or wind farm feeding the grid in your area the voltage can reach a staggering 260v if they are not set up correctly. You can get your local grid company (not electricity supplier) to check and monitor your voltage and if required they will down step your local transformer to try and get to 230v. I did this and not only save on blown bulbs but also on leccy bills and lengthen the life of all your electrical gear.

Trust me I'm an engineer.

It depends what sort of circuit they use, and 10V isn't all that significant anyway for supply voltage. For any using any sort of SMPS rather than just stringing them together with a resistor/capacitor (i.e. the rubbish, cheap, flickery ones) it won't make a difference.

WRT voltage making a difference to other appliances, it depends, hence why 'voltage optimisation' is at times of questionable value. For any purely resistive loads like incandescent lamps, heaters, etc, yes the lower voltage will mean lower instantaneous power, but it's not a free gain - lamps will in many cases be appreciably dimmer as the lumen drop-off for lower voltage is not linear (if anyone is still using incandescents at home) and any thermostatically controlled heaters will simply need to run for longer, and if anything the resistive losses in cables during that time will be higher, though without actually working it out the difference is likely negligible. Stuff like computers, other electronics etc use regulated power supplies and it won't make a jot of difference there. Again if anything, I2R losses in cables supplying them would be marginally higher due to higher current and many SMPS tend to be more efficient at higher voltages anyway. /voltage 'optimisation' rant.

The voltage rating in the UK is 230V with a tolerance of -6%/+10% precisely because of what you said, no-one went around changing transformer taps when we adopted '230V'. So 216.2 to 253V. If it's within that, good look getting a DNO to do anything.

"So 216.2 to 253V. If it's within that, good luck getting a DNO to do anything."
The voltage only has to spike above 253v once and they are obliged by law to investigate, usually putting a recording monitor in, in my case we have a lot of solar and wind turbines locally, on windy days the voltage would go out of spec, due to poor regulation on one or two turbines, they were more than happy to tap down the transformer.
voltage optimisers can cost upwards of £1500, getting your grid supplier to sort it costs nothing bar a few phone calls.

As for "computers and other electronics" yes they have regulated supplies but the extra power input has to be dissipated, that will shorten the life of the PSU if nothing else. One prime example is microwave ovens, the magnetron that generates the power can be compromised and lose 20% of it's life due to over voltage. Another is stuff with AC motors (washing machines, driers, dish washers etc.) and their drive capacitors, both can be damaged by over voltage these devises don't normally have the luxury of switched mode PSUs so the voltage to them goes up and can damage circuit boards. LED lamps will not dim noticeably (mine haven't) on an average day the over voltage was about 5%, and they weren't noticeably brighter on the very windy 10%+ days, they just blew then! negating any cost saving, when I pointed this out to the grid supplier I was sent a box of 20 GU10 bulbs, I still have most of them still in the box.

There is no 'extra power input' to be dissipated. Higher voltage results in them drawing less current - they are not linear devices, and nor does a higher voltage within spec reduce life. Properly-designed devices will be capable of dissipating spikes well above spec too. A modern computer power supply can operate worldwide and obviously won't draw twice as much when connected in the UK vs USA. In fact as I said earlier, they tend to be more efficient at higher voltages so draw less power overall.

Single-phase AC motors (of which there are very many types) would generally only be damaged if the voltage was high enough to break down winding insulation or start/run capacitors which are usually specified *way* above line voltage, amongst other things to protect against failures due to everyday voltage surges. In fact the windings would usually go through an insulation resistance test at roughly double the supply voltage, sometimes known as hi-pot or dielectric strength testing though they're not necessarily the same thing. Washing machines are different again as they're generally three phase motors fed from a variable frequency inverter drive.

If 5-10% over-voltage is destroying lamps, they're crap lamps, plain and simple. Voltage changes will not vary the brightness of properly regulated LED lamps, but may do so for the very cheap ones fed through resistor/capacitor droppers, however the difference still may not be as obvious as the fairly large difference seen with incandescents.

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Originally Posted by watercooled

There is no 'extra power input' to be dissipated. Higher voltage results in them drawing less current - they are not linear devices, and nor does a higher voltage within spec reduce life. Properly-designed devices will be capable of dissipating spikes well above spec too. A modern computer power supply can operate worldwide and obviously won't draw twice as much when connected in the UK vs USA. In fact as I said earlier, they tend to be more efficient at higher voltages so draw less power overall.

Single-phase AC motors (of which there are very many types) would generally only be damaged if the voltage was high enough to break down winding insulation or start/run capacitors which are usually specified *way* above line voltage, amongst other things to protect against failures due to everyday voltage surges. In fact the windings would usually go through an insulation resistance test at roughly double the supply voltage, sometimes known as hi-pot or dielectric strength testing though they're not necessarily the same thing. Washing machines are different again as they're generally three phase motors fed from a variable frequency inverter drive.

If 5-10% over-voltage is destroying lamps, they're crap lamps, plain and simple. Voltage changes will not vary the brightness of properly regulated LED lamps, but may do so for the very cheap ones fed through resistor/capacitor droppers, however the difference still may not be as obvious as the fairly large difference seen with incandescents.

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Can I remind you of Ohms law, current is proportional to Voltage X Current, then the power law power, Power equals Current X Voltage both physical laws you seem to want to break

May I remind you again I AM an engineer, with 50 years experience both commercially and as a Naval engineering officer, I have a degree, both in electrical engineering and electronics.

Sorry but throwing down qualifications doesn't make your previous post correct, but usually makes me shake my head (had that happen a couple of times recently). Yes, your first line of this post is correct, at least when applied to simple DC or purely resistive AC circuits, but also incomplete when it comes to e.g. AC circuits due to reactive (capacitive/inductive) elements (something I'd expect any electrical engineer to be fully aware of). It's also not as simple as just pointing at Ohm's law if you're relating it to a switched mode power supply input power vs voltage? Else I can't think what you're referring to, nor have I ever said otherwise.

As I said, look up universal power supplies/chargers which are supplied with phones, laptops, etc, they will generally be rated for a wide input voltage from 100-240V. This does not mean, as I believe you're implying, that the power supply runs horribly inefficiently at 240V, drawing the same current and wasting more than 50% of the input power as heat. On the contrary, many such power supplies are in fact more efficient when operated at a higher voltage. The reason for this is due to how switched mode power supplies work. There are different types, but at a simplified level, the first stages involve rectifying the input and feeding it through a regulated inverter - for different input voltages it can be as simple as varying the duty cycle of the PWM circuit feeding the inverter, in order to achieve a stable output voltage.

A common type of SMPS used for small devices like phone chargers is the flyback converter.

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Originally Posted by RichMc

Can I remind you of Ohms law, current is proportional to Voltage X Current, then the power law power, Power equals Current X Voltage both physical laws you seem to want to break

May I remind you again I AM an engineer, with 50 years experience both commercially and as a Naval engineering officer, I have a degree, both in electrical engineering and electronics.

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But if the lamps have a built on constant current regulator, (remembering that an LED is a non-linear device, so Ohms law is not applicable) changes in voltage will not affect brightness or longevity. If the are poor quality lamps fed with a simple regulator, then they will, as water cooled says) be susceptible to premature failure from power surges.

Buying the right LED is very different from buying incandescent bulbs. The brightness of LEDs, however, is determined a little differently.

Looking for PIR Floodlight for garden which is 4m2. What kind of watt should I be looking at, they have all moved to LED now so now sure how good the spread the light. I've seen 10w, 20w, 30w, 40w at Screwfix.

Also has anyones indoor lights lasted a few years. I'm changing LED bulbs yearly. Not the 25,000 hours quoted on the pack.

I have had only 1 led bulb pack up in 3 years, in my house I have about 18 led bulbs

Same, we've had LED lamps last several years of sitting room type use, not sure what that works out at in terms of hours. What sort of brands are you using, out of interest?

I think I've said before but I tend to use B&Q's Diall brand which seem pretty decent for the price and easily available. Some of the properly cheap ones you can get are some horrible capacitive dropper ones with a horrible ~100Hz flicker which you can see as a strobing effect any time you move stuff in the room. I suspect they're the type that people have bad experiences with, with regard to colour quality and life too.

Did you have a floodlight up in the garden already? Using the wattage of that would be a good starting point. Even a 10W would light it up but it depends how much light you need e.g. enough for putting bins out or to do some sort of work under?

One last thing, beware of wattage ratings of floodlights on places like ebay, they're often... optimistic?

Since moving to my new place recently, I've changed all the bulbs to LED at a max of 5W. Some of the original bulbs were a staggering 60W, practically blinded after turning them on. Also some bulbs were the original energy saver ones from 15+ years ago that start extremely dim and eventually work their way up to a full brightness of Percy green, but with the house not having gas, and including electric heaters, I need to do all I can for the electricity bill, especially when you have 3 bulbs in one fitting.

Even though I've been disappointed with IKEAs latest GU10 bulbs I don't have any GU10 fittings any more so decided to take a fresh look at all the other styles that I do have. B22, E27 & E14.
IKEA had some 0.9W E27 bulbs and they're actually really good, especially when I need 3 of them in the hallway. Less than 3W when on, awesome. I can leave them on completely guilt free when I pop down to the shops. The only thing I will say is that they're not able to penetrate a frosted covering so it's a little dimmer vs a clear or no covering, but as I don't spend much time in the hall they're ideal.

I then moved from 3x 9W bulbs in the kitchen to IKEA E14 3x 3.5W which produce the same amount of light.

In the lounge I had a previous left over Homebase 5W unfrosted E14 TCP bulb, I then went to Homebase to get a further 2 of these to match the kelvin, but they only had 3.5 or 3.2W, can't remember, thankfully they produce exactly the same amount and tone of light as the 5W, so in just 5 years they've become slightly more efficient which is good.

Finally in the bedrooms I used some left over frosted 5W TCPs.

Likewise, I've yet had an LED bulb blow, but then I've never been in the same place for too long and usually leave them

I bought 3 LED bulbs from The Range a few weeks ago now one of them is dim and takes forever to turn off. Not sure whats going on with that

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Originally Posted by Jonj1611

I bought 3 LED bulbs from The Range a few weeks ago now one of them is dim and takes forever to turn off. Not sure whats going on with that

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When you say takes forever to turn off, do you mean a glow that you can mainly see in the dark? Or is it full on?
I had a permanent glow with on certain GU10 brands. It's almost like it holds a charge as though there's a load of capacitors in there... It wasn't an issue for us as the ones that glowed were put in the hall, and actually turned out to be useful when getting up in the night to use the toilet. But I never tested whether it was still consuming any electric. I've yet to come across that with any other fitting on bulb

I mean its dim when it comes on rather than bright and when you turn it off takes like 10 seconds to actually turn off.

I am not having much luck with LED dimmables. Some MK dimmers it seems to me lack resistance to operate properly with low wattage bulbs. Drop in an old bulb all good in every part of circuit. Take all bulbs to low-W and flickers intermittently or like crazy depending on dimmer settings.

edit for clarity this is a new dimmer advertised for LEDs and the bulbs are within the stated spec, well in the manufacturer's tabulated power requirements etc.

Ah yes my bulbs in the lounge are supposed to be dimmable but you turn them down and they just hum

For the bulbs that glow constantly, are they fed from dimmers or standard switches?