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Blog Archive

Sunday, March 13, 2011

Replacing MR16 Halogen bulbs with LED equivalents

If you have read my other blogs about GU10 mains voltage halogen lighting, you will know that I have mostly replaced these bulbs with LED equivalents. they cost more, but last longer, are cooler and use a fraction of the energy. a halogen bulb is typically either 35 or 50 watts. most LED bulbs are 3 watts.

While the bulbs in my house are predominantly GU10 mains halogens, I do have a couple of MR16 bulbs. These are a different type of halogen that operate from a 12volt supply. I should mention at this point that I don't have any dimmer switches in my house. Now some mains voltage GU10 LED bulbs are dimable (always check first).


MR16 bulbs have two pin connectors rather than the lugs found on GU10 bulbs. GU10's use a push and twist method of connecting to the socket. the MR16 simply push in place with metal clips also gripping the edge of the bin base.

They use a separate power supply , either a transformer (old type ) or a switch mode power supply(newer) to convert 250v AC mains to 12vDC. A transformer is a hefty box while most now use a switch Mode Supply, which can be made very cheaply. They are small light box, perhaps the size of two boxes of matches.

In the picture you can see one next to the vent hose in black. these transformers are often tucked away in the ceiling cavity. In my case the extract fan units were accessible , as the extract units vented up through the attic and out through dedicated tile vents via plastic hoses, the type used by tumble dryers

Because of the lower voltages, the MR16 bulbs are the type used in my shower fittings. You can see a common type of extract fan, with a central MR16 light.

Now I had tried LED MR16 equivalent bulbs in these fittings , but they either flashed briefly then went off or flashed repeatedly like a strobe light. Neither was ideal for showering.

The reason these LED 3 watts replacements didn't work is due to the power supply. the original power supply units fitted would only work with a minimum load of 20-30 watts. However the LED bulbs are only 3 watts. I have also read of people with a single power supply running a number of lights. When replacing with LED bulbs they found they had to keep at least one halogen in the circuit to keep the load high, or they would experience the strobing effect.


In my case these MR16 bulbs are fed from dedicated power supply units. the solution was to replace the power supplies with units designed for LED lighting. these can handle loads down to 1 watt. You need to ensure that the LED supply you choose can handle the correct load. In my case it's 3 watts from a single light. if you have a power supply driving multiple bulbs , which is normal too, you need to ensure the power supply has a maximum load sufficient for the total of the wattage of the bulbs i.e if you run 6 LED bulbs at 3 watts each , the power supply needs to have a maximum greater than 18 watts



in this picture you can see an LED driver or power supply, especially for LED MR16 replacement bulbs. Above it are two varieties of LED MR16 replacements, a Phillips Brand cost circa £20 at B&Q with 3 super-strong individual LED's and a Surface mount unit from SimplyLED for £11, who also supplied the driver for £8. Both provide good bright light. the SimplyLED is described as "warm white", meaning it has a slight yellow tint, they also do a "brilliant white" bulb which has a slightly bluish tint. This might be preferred by some, to my eyes fluorescent lights have a similar colour tint.



replacing the exiting transformers is relatively easy however
WARNING
THIS PROCEDURE INVOLVES MAINS ELECTRICITY.DO NOT UNDERTAKE THIS IF YOU ARE UNSURE . IF IN ANY DOUBT CONSULT A QUALIFIED ELECTRICIAN. ALWAYS TURN OFF THE MAINS BEFORE ATTEMPTING THIS WORK. NEVER RELY ON THE WALL SWITCH TO ISOLATE THE CIRCUIT WHILE DOING ANY WORK. ONCE THE MAINS IS TURNED OFF REMOVE THE EXISTING HALOGEN BULB FIRST.


Once you have unscrewed the cover you can see that there are 4 screw terminal connections,
one set of two for the 240v mains input , labelled L for LIVE (Brown) and N for Neutral (Blue)
the other for the 12vDC output. the output is polarised, so the transformer indicates positive (+ve) and negative (-ve) outputs, though neither of the bulbs had any polarity markings and both appeared to work connected either way.

I simply disconnected or cut the wires from the old transformer inputs and outputs, stripped and prepared the wires correctly, and connected to the new transformers. I double checked that no copper wire was visible, and that the screw terminals were not binding on the insulation. I then gently pulled each wire to see that the connections were sound. I then put the covers back on.


I also tried a different type of transformer on another light. This kind I purchased from ScrewFix for £12. exactly the same procedure except that the inputs and outputs were at opposite ends.


once I was sure of all the wiring, I put the new LED bulbs into their sockets before turning the mains back on. Had I left the original high wattage halogens in the light fittings, I might have damaged the new power supplies with the heavy loads. It was then a simple case checking the bulbs illuminated correctly from switch on, which they did




84 comments:

lights grow said...

It is very nice and good idea of LED light lamp.I like this halogen with LED lamp.It is so excellent idea.

Mr Ives said...

Many thanks lights grow, I think it is a good idea too.

decorative lights said...

Not bad idea its good to do that because the efficiency is there and also have a longer life than the traditional light bulb.. thanks

Ed said...

I'm considering this for our kitchen. Can you give a more detailed subjective description of the relative light levels of the different MR16 bulbs you tried, compared to each other and to the original halogens, what was the rated wattage of the halogens, and so on. I need to buy 6 bulbs, and £10-£20 each I need to be sure I'm getting the right ones, and this kind of information seems to be a quite closely guarded secret!

Mr Ives said...

Hi Ed,


It's very hard to give you 100% solid advice here as light levels can be quite subjective. If you are replacing MR16 bulbs 9as opposed to GU10) you may well also need to replace the transformers, as the Halogen 12v supplies will have a minimum load bigger than the total wattage of 6 LED bulbs 9as per blog).

In general terms I have found the LED equivalents slightly dimmer that halogens and with a more yellow tint. However for many applications (bathrooms) this is less important. I'm awaiting a 6watt GU10 bulb to try for a few applications in my kitchen which require a bright spot light beam.

I'd also add that suppliers such as http://www.simplyled.co.uk seem to have a no quibble money back policy. Why not try one, if you like it, get more, if not get a refund. Nothing to loose.

Anonymous said...

Hi Mr Ives
I notice you have them fitted in your shower extractor which i also want to do so i can do away with 35w halogen?
However i notice the side of the 20 x SMD bulb has open vent slats?
How does this cope with moisture in the shower? I have been trying to find a sealed glass lensed smd bulb but am struggling to find one?
Regards
Vic

Mr Ives said...

Thanks Vic, you raise a good point. many of the LED bulbs have cooling vents at the back. I don't know if these do present a problem in a moist atmosphere i.e a shower . The bulbs are in a vented tunnel and do get quite warm, so I would assume that any moisture would be vented away fairly quickly. If in doubt, if you look at the Philips MR16 bulbs I also show, they are self contained and have no vents, so perhaps these would be the best choice of MR16 in a damp environment

protasio said...

I've 1 question. I bought some led smd bulb to change my old halogen lamps.

I try to replace it directly, but i got very low light compared to halogen as you can see here.I noticed that the halogen lamp were single conected to this.

I know it is 11,5V output but the difference should matter to the 12V, but i tried to connect to a 15V laptop charger and it's fine.

My question is, it's because of the halogen transformers? I don't think is a load problem as I didn't have the any strobe, just very low light.

I cannot change the transformers as they are inaccessible over the ceiling (poor constructor), so what can i do?

By the way, great blog ;)

Mr Ives said...

Thanks Protasio,

Sorry that your LED bulbs are not working out. It's hard to say why they are significantly dimmer, and not always easy to determine from pictures. A few thoughts :

1) The SMD bulbs are effectively an array of point sources, each of which is considerably dimmer than a halogen but collectively they achieve roughly comparable brightness. It could be that with a halogen you are used to a very direct beamed style of light ? It's hard to tell from pictures I know. I have this type in my bathrooms and it's fine. however above work surfaces in my kitchen I still rely on a few halogens for the spot beam. There are also LED bulbs which use 3 super bright LED's, which I have used mostly through my house which are closer to the style of light from a regular halogen - I have used Interlux brand.

2) It could be voltage related. I'm not sure where you are located. I wonder why your MR16 bulbs are running on 11.5v whereas mine run on 12v. I can see from your transformer that it outputs 11.5. With at least one halogen bulb in circuit I would not expect to get strobing as the load is still comfortably within the load specification due to the halogen. Having one of these SMD bulbs alongside a halogen will always look different.

3) Those bulbs are really cheap. I know in the UK prices tend to be higher, but I'm paying, even on the internet around $20 per bulb. Your's might be perfectly fine, but I wonder if they are up to spec ?

I can't offer much more advice. Perhaps try a different brand/type ?

I have always returned bulbs I didn't like and get a refund or swapped for a different type

best wishes

Jonathan

Macgyver said...

Hi,

I have tried several of the eBay LED MR16 lamps and found that the 4w version which seem to be the most common (have an aluminum spiral back heat fin) seem the best and produce about an equivalent of 35w halogen. So for every two 50w halogens you would need to fit 3 LED 4W lamps. Still cheaper than a single 50W halogen. Also, they are more directional with about 38 degree beam. Best if fitted to a higher roof so the light spread is greater.
Dont get the 5w version. All they have done with these is add an extra LED (5 LED's instead of 4) but the little mini power supply inside is the same....they dont output as much light and buzz and whistle.
Using the 4W LED's on a 11.5v transformer will produce a noticeable less light output. ideally the voltage needs to be at least 12 to 12.5v.
I have mine connected through a double pole relay that switches between AC transformer 12v and a 12V DC solar panel/battery system and i get about 15% more light output from the 12V DC connection.
So far by replacing 20 of the 50W halogen lamps with the 4W LED versions (and disconnecting the transformers so that one single transformer runs 4-6 LED lamps depending on the room used - each transformer uses 10w in heat loss...)the quarterly power bill decreased by more than $50.
If anyone needs any more info on all of the R&D i have done so far i am glad to help.

Macgyver said...

Hi,

I have tried several of the eBay LED MR16 lamps and found that the 4w version which seem to be the most common (have an aluminum spiral back heat fin) seem the best and produce about an equivalent of 35w halogen. So for every two 50w halogens you would need to fit 3 LED 4W lamps. Still cheaper than a single 50W halogen. Also, they are more directional with about 38 degree beam. Best if fitted to a higher roof so the light spread is greater.
Dont get the 5w version. All they have done with these is add an extra LED (5 LED's instead of 4) but the little mini power supply inside is the same....they dont output as much light and buzz and whistle.
Using the 4W LED's on a 11.5v transformer will produce a noticeable less light output. ideally the voltage needs to be at least 12 to 12.5v.
I have mine connected through a double pole relay that switches between AC transformer 12v and a 12V DC solar panel/battery system and i get about 15% more light output from the 12V DC connection.
So far by replacing 20 of the 50W halogen lamps with the 4W LED versions (and disconnecting the transformers so that one single transformer runs 4-6 LED lamps depending on the room used - each transformer uses 10w in heat loss...)the quarterly power bill decreased by more than $50.
If anyone needs any more info on all of the R&D i have done so far i am glad to help.

Mr Ives said...

Thanks Macgyver,
You have clearly done a lot of work in this area.

I'm a bit confused as to why US MR16 bulbs are run at 11.5 volts rather than 12v by default ? As you say - they give 15% more light whn run at the higher value which is in spec.

I'm aware that in the US mains electricity is at 110 volts, so 11volts is a nice 1/10 of the mains.

In UK & Europe we run on 240-250V so 12v is a nice 1/20

This would make sense to me if we were still all using transformers based on primary/secondary winding rations, but I assume all the power supplies for MR16 (erroneously called transformers by me) are actually switched-mode devices, where winding ratios are not an issue ?

Macgyver said...

Hi,

Sorry, may be some confusion. I am in Australia and we also have 240v. I was referring to the secondary voltage of the AC transformers (240V to 12V AC). Some transformers are rated at 11.5V AC on the secondary and others are 12V AC.
There is a light output difference of about 15% between the two types, that is the 12V AC type give a slightly brighter output - as you may expect.
I have tries both the switch mode power supply type and the actual "transformer" type and you can run into issues here. The switch mode type output is usually a high frequency oscillation of around 50Khz at 12v AC. The issue here is the LED lamps cant transfer this high frequency as they are designed to work at 50/60Hz. The result is either no light output or in some cases just a pulsing light.
For this reason you need to purchase specific LED type switch mode power supplied which do not have a high frequency output. Or do as i do just use the old style power transformers. Yes, am aware they are not as efficient as the switch mode type but the difference of efficiency is at most about 6W and given the fact i take out of circuit several transformers as i need only one single transformer to run several 4W LED lamps - and - i have also gone from 50W halogens to LED lamps, the small difference in efficiency is insignificant in my books.
Let me know if you have any more Q's.

Anonymous said...

Hi,

The builder of my house installed MR16's in every room which makes around 100 in total. I've just bought some LED equivalents to try and reduce the electricity cost but can't get any of the LED's to work when i swap them out with the halogens.

I had not realised the transformer point so its good to read that thanks. I've found one transformer in the loft connected to the lights but is likely that this unit will feed an entire circuit or will there be one unit per room?

I am hoping the former otherwise I'll need to locate each unit!

Also, if i do change the unit the will it still run some halogen lights?

Wondering if this might turn out to be more hassle than its worth!!

Thanks
John

Mr Ives said...

Hi John
Wow - 100 Halogens. Turn them all on and its 5 units per hour !

hard to say if the transformer feeds a single bulb or multiple. You could look at the load its able to support. You could disconnect it , then see how many halogens no longer came on ?

I'd expect a halogen transformer to be able to support a kix of LED and halogens provided the load was not below the minimum spec for the unit. Whereas the LED specific transformers can only support LED bulbs due to the lower ratings.

If you replace one halogen with one LED in various places around the house does it always result in the LED bulb not working ? if so I'd guess you might have a transformer for every bulb, which as you say, would be complex to replace all. I d expect a transformer to be supplying multiple units though

If you have recessed lighting in your upstairs is there any chance to trace the wiring in the attic ? that way you might be able trace multiple fittings to a single transformer.

Tom said...

Hi.. I read your article..nice post..

LED Strips

Anonymous said...

I am another sufferer with far too many halogen MR16s with individual transformers. Can I replace one halogen transformer with one led transformer which will serve more than one lamp, or do I need a new transformer for each lamp.?
I have huge electricity bills so maybe the saving will be worth the outlay - will need to get my abacus out to work it out!
Great blog and many thanks for the guidance. Hambo

Mr Ives said...

Hi Hambo,

I think it should be possible to power multiple MR16 bulbs from one driver/transformer with a couple of caveats :

1) The driver needs to be able to handle the total load of the bulbs, so for example if your bulbs are 3 watts and you want to drive 3 bulbs , you need a driver capable of handling 9 watts. I guess you could use non-LED drivers providing the load was within their range. however most of the conventional halogen drivers I have seen were in the 30 watts range, so you'd need to drive circa 10 bulbs for it to work.

here are some drivers with higher load values

http://www.simplyled.co.uk/LED-Driver-Transformer_B23PJ8.aspx


2) Wiring. if you have individual drivers for each MR16, then I guess each bulb socket has a short length of wire from the bulb socket to the driver. The mains wiring would lead to the driver. hence if you wanted to wire multiple bulbs in parallel to a single driver you may have to carry out substantial re-wiring of the cable runs. This may be within your capability, but if in doubt I'd get an electrician to do it. I would be reluctant to have too many junction points between the socket, its existing wiring, and any necessary additional wiring back to the driver. I guess it depends partly on how its wired at present and how accessible the wiring is. Downstairs recessed lighting may have limited access in the ceiling space. Upstairs where you have access through the roof space might be easier.

12V Halogen Bulb said...

Hi

We are very thankful for sharing with us a information about halogen lights

JPR Fan said...

Hi Mr Ives
I have a bar light in my kitchen comprising 4 GU10 halogens; have decided to replace with LED downlights recessed into the ceiling. Two electricians I've had recommended to me are offering different advice. One says I will need only 4 LEDs (80mm 50W equivalent), the other 7 x 5w LED. I want the warm white as the other seems to harsh. As you've carried out replacements, what is your opinion? Thanks

Mr Ives said...

Hi JPR Fan,


a very good question, and no easy answer

I have found that LED GU10 bulbs have come on a lot. You can get bulbs now that are brighter than halogens, but even the best still have that slightly clinical blue/white tint, even the ones described as 'warm white'. Some people like this over the warm yellow of the halogens.

I recently swapped a couple of kitchen downlighters for the nextgen LED bulbs which they have at Simplyled.co.uk (sorry not sure if you are UK or not - Wales perhaps - JPR Williams ?). They are good and give good light for working beneath but they are not quite as cosy as the old halogens. These bulbs use an array of 20 or so SMD LED's , each with a small diffuser on it. The light is good, though the multiple point sources give rather complex shadowing.

The bulbs which employ fewer bulbs (i.e 3 or 4) I think may have a better colour but are not as bright.

Perhaps a way forward is to buy 4 LED GU10 bulbs from a reputable online seller, one that has a money back guarantee (simplyLED.co.uk have this), then you can try them in the existing fitting. If you like them, keep them and refit them in your recessed units when you get them done. if you don't , simply return them, and either carry on, or get receded fitted with halogens.

JPR Fan said...

Thanks - Wasn't sure I could just put in LEDs to existing fitting, but will try that. (You're right -JPR W)

Mr Ives said...

JPR Fan

If they are GU10 bulbs i.e run off mains voltage, then you can swap in LED version in no problem.

It only gets a bit more complicated if they are the low voltage version (MR16) where you sometimes have to change the transformer for one that will drive a load as low as a few watts.

Vj said...

Hi.

Great blog, hoping you can advise on my current situation

In our kitchen, I have 12, yes twelve MR16 50W bulbs. I am looking to replace these with LEDs, but would also want to be able to selectively control them by remote. Is it possible to get programmable LED drivers (which I know I need) so that I can set them up on banks of 3 or 4 etc

Mr Ives said...

Hi VJ, thanks for the coment.

Interesting question. The short answer is I don't know for sure . Certainly LED drivers exist that could drive up to 6 bulbs such as this one http://www.simplyled.co.uk/30W-LED-Driver-Transformer_ASI5S.aspx?nh=0
You could then have banks of LED bulbs from a single switch, which could in turn be remotely controlled via a remote light switch. I don't know if more sophisticated systems exist which might allow multiple discrete sets of lights to come on. It would be a good idea and preferable to dimming in my view. Sorry not to be able to give a better answer. My MR16s are all single driver units in shower extract fans. My kitchen lighting is the mains voltage version the GU10

Geomax said...

Good post, Thanks for the info. I'm also in Oz and want to replace MR16 halogens with LED. Again our current wiring is one switchmode "transformer " per MR16. Given we are working with 12V DC when wiring multiple LED replacements to a single transformer are they wired in series or parallel?
Does it matter?

Mr Ives said...

Thanks, I'm pretty sure you'd need to wire the bulbs in parallel. that way they'd all be the same brightness (same voltage) and would also keep going if one failed (hopefully not a problem with LEd's but .....)

Anonymous said...

Hi,

I Understand this in principle but the British housing light system has an earth wire which is not shown in any of your pictures?, what did you do with this wire? Kind regards, Paul.

Mr Ives said...

Hi Paul,


there is no earth wire because I was not replacing mains halogens with 12v LED's. I was replacing an existing 12v halogen transformer with a 12v LED transformer. MR16 is the type of Halogen lighting that uses a 12vDC supply. My showers were already wired for this and had no earth wire.

GU10 is the type of halogen lighting which runs from 240v mains (UK). In that case I just get LED GU10 bulbs and don't have any need for transformers. The GU10 light fittings have a screw terminal to ensure the metal of the fitting is earthed and you'd attach the earth wire to it.

Boatlamps said...

Just to bring this subject up to date. I have been developing a MR16 LED lamp that functions perfectly on electronic 12 volt halogen lighting transformers. The lamps are exactly the same form/size as standard halogen lamps. They use 6 Cree LEDs and have comparable light output as a 35W/50W halogen lamp. The secret is a new LED driver built into the lamp. This new electronic controller allows the lamp to be used with most electronic transformers even those that require a minimum lad of 20W.

Nathanael said...

Not sure what exactly you were referring to, but dimming a bulb DOES decrease energy use. Old rheostat dimmers didn't save energy but those aren't used anymore.

Mr Ives said...

Thanks Nathanael , I must admit I thought that most dimmers still used a
rheostat . I stand corrected, I see they are triac based now. I don't use them. I'll update the blog - Thanks

tim441 said...

thanks for all the useful info & comments! My problem is that i cannot use the wire clip on my replacement led bulbs to hold it in place. It will not hold in place as the bulb glass makes it sit a little proud. Does anyone have any suggestions please?

Mr Ives said...

greetings tim441 and thanks for the coments. You raise an important point, which is that while the connections are standardized across GU10 and MR16 bulbs , be they halogen, CFL or LED, the precise dimensions vary a lot. You have found that the geometry of the LED replacement is sufficiently different that the metal clasp does not hold it in place ? I think all I can suggest is to return it to the supplier. if the bulb does not fit, despite apparently being a drop in replacement, that is good grounds for a replacement. Perhaps try a different brand. I think the Philips one I have is closest to a halogen bulb. simplyLED I have found very good and they will replace bulbs with no quibble, simply if you don't like the light colour.

Anonymous said...

Hi there. Like many of the comments above, I have a house full of 12V MR16 lamps - most of which I'd changed from 50W to 35W. I had a solar pv system installed earlier this year, so it seems ludicrous to waste electricity with halogens, and consider that I need to move down the LED route. So, I could go for MR16s with new drivers - or - change to mains voltage GU10's (except the bathrooms where I'd rather stick with 12V). For 230V, there seem to be a couple of options. Either change the existing fittings entirely - or convert the lamp holders to GU10. For the latter, there are numerous sites offering replacement holders (plus cables and connector blocks). However, my concern is with earthing of the fittings. Some of these conversion "kits" say they are class 2 double insulated and require no earth connection, but then others have a metal tab (fit fixing into the spring clip) with an earth connection. This worries me somewhat. I would expect that earthing the fitting is necessary. What do you think on this? By the way, all of my fittings are Aurora fire-rated type with pressed steel enclosures.
Regards, Paul

Ian said...

I've got some MR16's that are on transformers recessed and some which are light "blocks" if you like. A single black block with two parallel bars the 4 MR16's attached. All done by previous owner. How can I tell if those "all in one" units are compatible? Just buy a bulb?

Mr Ives said...

You could just buy a bulb, but the important thing is the minimum load the transformer in the block supports. LED MR16 are typically around 3 watts, so 4 of them is 12 watts. The MR16 power supply needs to be able to drive loads that low or you will get the strobing or it simply will not go on. If you remove the transformer you usually can see the parameters of its input and output written or embossed on the case.

Decoled said...

I'm only using LED equivalents from now on and the fact there are lots of retrofit lights is helping.

Sze said...

Hello Mr Ives,

Thank you for posting this, it is certainly useful even in 2013!

The place I live has halogen lights (MR16), and I was thinking of swapping them for LED ones.

Having tested one, the light works perfectly, but there are still 2 questions on my mind before I carry on:

1) Is existing drivers, are they safe? I.e. to leave on throughout the night?

2) Are the energy-saving benefits lost if I use the existing drivers?

Any guidance you may have on this would be much appreciated, thanks!

Regards,
Sze

Sze said...

Hello Mr Ives,

Thank you for posting this, it is certainly useful even in 2013!

The place I live has halogen lights (MR16), and I was thinking of swapping them for LED ones.

Having tested one, the light works perfectly, but there are still 2 questions on my mind before I carry on:

1) Is existing drivers, are they safe? I.e. to leave on throughout the night?

2) Are the energy-saving benefits lost if I use the existing drivers?

Any guidance you may have on this would be much appreciated, thanks!

Regards,
Sze

Mr Ives said...

Hi Sze, Well to answer your questions I would say 1) Yes and 2) No.

I have some bathrooms where the lights sometimes are left on over night and have had no issues, plus being cooler there is less risk with LED IMHO

Whether your drivers will work with LED depends on the minimum load the driver supports. Most halogens present a load of 30-50 watts per bulb. Most LED present 3-6 watts per LED. Hence if the driver supports, say 5 bulbs, and the minimum load it supports is 20 watts, you might find that you can replace 4 of the 5 with LED and the load is still comfortably within the LOAD of the driver because of the high load of the last halogen. One the last bulb from the driver is replaced, the total load drops to , say 15 watts which might be below that which the halogen driver can work with. How many bulbs do you have running from a driver ? Its useful to have a look at the drivers as they have their minimum load printed or embossed on the case.

Sze said...

Hi Mr Ives,

Thanks for the prompt response, I particularly appreciate the safety tip as that is always the biggest concern.

Unfortunately all the drivers are within the ceiling and not visible to me.

The only bulb which I have replaced is that for a porch light, which originally was just one halogen lamp (i.e. replaced 1 of 1), and turned on/off by light sensor. This may have an influence on it still working, but I am certainly no expert!

Within the rest of the house they're mostly of between 4-6 halogen lights [some are also dimmable], and as before concealed, so unfortunately I can't read/replace the drivers easily, or at least not with my lack of knowledge/skills.

Thanks,
Sze

Mr Ives said...

Hi Sze, So maybe replace the bulbs as you go. You may find you can replace them all with LED bulbs and it all works. Great. You may find that you can replace some and there is a tipping point where either the bulbs no longer light or they blink very fast. If this is so, reverse the last step and resign yourself to having at least one halogen off that spur. With a bit of experimentation you can fit the halogen where its superior colour warmth makes the best effect. Good LED bulb suppliers have a no quibble returns policy so you should be able to return any excess LED bulbs you might have.

Sze said...

Hi Mr Ives,

Thanks! Will do as you suggest, hopefully it works out ok :)

Very informative blog btw, thanks for keeping it up!

Cheers,
Sze

Anonymous said...

Hi, I founf my hamelton beach track light transformers are all marked 11.5v. I bought some bulbs from hongkong a while back, they work great.
I bought 10 more from two different sellers, and found they flicker. So i cracked one open and took the black and red to my 12v car battery and they worked great. Basically found that most these bulbs were specific built for 12v input, not 11.5v,
They flicker because the bulb is starved of voltage. The circuits are built based on 12v voltage drop. So the transformer can't supply it.

Mr Ives said...

Hi Anonymous,


Thanks for the coment. Some other posters have had 11.5 bulbs. In the UK I have not seen these. Are you sure the issue is voltage and not load ? I'm guessing you have a transformer driving more than one bulb. When you introduce your new bulbs you get flicker. If you run the new bulbs in a light fitting which retains at least one original halogen, does this help ? if so that would imply that the transformer is unable to drive the very low loads required for LED. I wouldn't expect a flicker from a voltage drop ?

lissie said...

I have GU 10 halogens through out the house and when I discovered LED bulbs they seemed a better solution.

HOwever I installed 4 and 2 have already blown within 3 weeks - is this just bad luck - or can you not combine LED and halogen on the same circuit?

Mr Ives said...

Hi Lissie, sorry you have had some bulbs blow. They should last for years. Since I have been using them I've had one go out of 40 throughout the house. If the bulb went within 3 weeks, I'd get them swapped or your money back.Sounds like these are not very well made .How much did you pay for them ? In the UK I'm paying circa £10 per bulb which is around $18 NZD

Anonymous said...

HI
if a 12volt 35 watt halogen lamp and fitting are to be replaced by a 12 volt equivelant LED does the existing transformer and fitting require to be changed? thank you Brian

Mr Ives said...

Hi Anonymous, the honest answer is : possibly.

It all depends on the minimum load that the existing power supply can handle. Some are happy to go down to a few watts which is what your LED bulbs will draw. However in my case , the power supplies would only go from a load that was higher than the draw from my LED's, which is why i replaced them. You either have to a) Look at the writing on the transformer to see what the minimum load is or b) Try it and see

TrevorM said...

I have obtained six MR16 LED bulbs and 2 LED drivers online to replace the existing halogen bulbs and their electronic transformers in my kitchen. On the face of it this seemed to be quite a simple job but the drivers came in a plain white box with no instructions. After researching the project on the interenet I have come across various recommendations regarding the installation. I currently have 3 lights connected to each transformer and the new set up needs to run in the same way. The LED drivers are marked constant voltage and rated at 24W being Lumilife model TRAN-24 (the bulbs are Lumilife 4W) but only have a pair of connectors at each end. Assuming the end maked "primary" is for mains input marked L and N, it follows that the secondary terminals (+ and -) are the 12V outputs. However the advice I have seen refers to both series and parallel wiring although I believe parallel is the way to go with constant voltage drivers? I am wondering if the Halolite 1-16w LED constant voltage driver sold in the UK by Screwfix (product code 85503) would have better suited my needs as it has 3 pairs of outputs. Would this simply have meant connecting up the existing wires to the outputs on the new driver.

Any advice anyone can give would be much appreciated.

Mr Ives said...

Hi TrevorM, I have not tried either series or parallel arrangements as my only MR16 bulbs have a dedicated driver for one bulb. I would be pretty sure that the bulbs would be arranged in parallel to achieve a constant voltage across each bulb and also to ensure that loosing a single bulb wouldn't loose the other 2. I'm not sure about bulb polarity, since while the power supply has - and + labels, the bulbs do not. I assume they can be plugged in either way

linda kelley said...

I am looking for a light for my kitchen. A fixture I found uses 3 GU10-16 50w halogen lights. Can I replace with dimmable led bulbs.

Anonymous said...

Hello

I want to replace all my halogen (48) bulbs with 3 watts LED bulbs.
But completely on a 12V 102 AH Battery with 100 watt solar panel.
Basically i want to run all my lights on battery only

Do i still resistors or regulator or can i run it straight.?

Thanks
Mark



Mr Ives said...

Hi Linda,
Yes you can get LED GU10 bulbs which are dimable . I know simplyled.co.uk stock them and will refund if there is a problem.

Most of this thread is about the low voltage MR16 bulbs, the GU10 is similar but runs at full mains voltage, it does not require a transformer . I have about 40 GU10 bulbs in my house which i have gradually replaced with LED versions.

Mr Ives said...

Hi Anonymous,

Intriguing idea. I cant honestly answer your question. While a lead acid battery is nominally 12v i suspect that is under load, and the voltage may be higher with a light load like an LED bulb. 12 volt regulators are quite easy to find.

However are you going to wire all 48 bulbs in parallel ?

Id also look into wether that solar unit will sufficiently charge that battery ? This kind of question routinely comes up on the green living forum, you might like to place the question there, there are a number of users with home grown solar setups just for lighting

Anonymous said...

Just wanted to say thanks for this information. I purchased some 3W LED replacements for my halogens and they flashed on and then went dark. Your page explained the problem (my transformer's minimum load is 20w) and gave the solution clearly. I am now in possession of some 0-50w transformers and will be installing them shortly.
Many thanks

Mr Ives said...

Many thanks anonymous for your kind words. Good luck with the new transformers.

Big Fish said...

Hi,

I have changed 8 x MR16 50W bulbs for 8 x 5W (80 SMD) LED's. Each light has it's own transformer with a load range indicated at 10-60W. They are all working perfectly even though they are less than the minimum load. On the basis that they are working OK, is this safe re the transformer?
Than kyou ofr your help. P.S. What a superb blog!!

Wayne said...

Great thread. I need to ask I have MR16 bulbs on a dimmer. I have tried swapping to dimmable LED’s and it is a pain. Some work some do not. I have tried different makes and it seems different transformers work with different bulbs ect. The manufactures don’t really know the answers. So I thought this would be easier and cheeper ( LED GU10 seem to be less expensive and have more choices than MR16 when looking at dimmable ) to swap to GU10 fittings for LED. Can I cut off the transformer to each light and put in GU10 connector and then a GU10 LED bulb ? Will this remove the load issues with the transformer or will I just run into issues with the dimmer switched that I have on the walls ( they are electronic ) ?

Mr Ives said...

Hi Wayne, I see your problem. remember though that the GU10s are mains voltage , so the wiring would need to be upgraded to support mains current. While the current used by LED bulbs is small, the wiring would need to be sufficient to support the option of Halogens being plugged in either by accident or by a future user of the house or flat, who may not be aware of any wiring thats only able to take an LED load. You're right that GU10's are mucg=h easier, but I think you would need to upgrade the wiring too, not just remove the transformers.

As an alternative and this is just me, I never needed a dimmer, so perhaps think of removing dimmers, or perhaps making the lights zonal i.e rather than one switch turning on 8 bulbs, have two switches each controlling smaller number, then you could use them in combination or together

Anonymous said...

Hi Mr Ives et al

Thanks for this ... I've been changing over from halogen to LED lighting and worked through all these problems before finding your blog !!! It would have helped with a number of issues !!!

As I now find, the use of the word "transformer" as you say, is over simplified and not at all correct for LED's ... what I find is -

12v Halogen lamps usually have a 11.6 Volt AC "Transformer" and being incandescent filament lamps, they don't mind the polarity of the applied voltage

LED replacements require a 12 Volt DC Driver, DC being the important factor, giving a constant 12 volts polarity

This is why many people find LED's glow dim, flicker or just don't work. Find a suitable 12V DC driver and you should have no problems.

In answer to the subject from 'Anonymous' - if your charging circuit is regulated from the solar panels, it is unlikely that it would exceed 13.2volts ... the 'open-circult' voltage from your battery (off-load) should be 12-12.2, so with the fact that LED's are to a great extent self-regulating, I reckon you should be fine. I assume you would have some kind of over current and over voltage protection built in ...

Thanks again

Philip Murray said...

Excellent info here and I'm now using this to start to replace halogen MR16 lamps and the transformers.

The kitchen has two sets of 4 MR16 lamps, each individual lamp connected to a transformer. In each set of 4 one lamp fails to work. Any ideas on that? Don't want to spend a lot of money on LEDs only to find I still have failing lamps.

Justin Foss said...

Hi there

I have just moved into a house that has 9 MR16 down lights in the living room (3 rows operated by 3 switches).

The LED bulbs I have bought to replace the halogens are really bright, would it be safe to leave the 3 bulbs in the 3 centre downlights but not have them connected to the wiring so they do not light?


Mr Ives said...

Hi Philip Murray,

Apologies not getting back earlier, Christmas etc.

I cant really understand why you have. Failing bulb in each set. I assume if you replace the bulb it doesnt work ? This suggests that the LED driver is bust or you have a connection problem. You could try a single LaeD bulb and swap it with the offending position to see if this helps ? My suspicion is something is wrong with the transformers/driver for that position

Mr Ives said...

Hi Justin, interesting post as LED bulbs have come along way. . At the start it was hard to get a bulb as bright as a halogen. now you have the opposite problem, which is an indication of progress, despite it inconveniencing you .

Not sure what you mean by not wired, could you not simply remove a few bulbs, is that what you mean ? You probably can get less powerful LED bulbs but i assume you already have paid for the bulbs. Some sellers on the web have a no quibble money back or refund, such as sumplyLeD.co.uk. I think id simply leave a bulb .

If you mean plug the bulbs in but disconnect the bulb holder from the driver, yes that could work, but iyou would need to esnure that all wiring was terminated safely in the ceiling or recess. Surely just leaving bulbs out would be easier and safer. Also lighting can seem bright when you change it but over time you get used to it very quickly, so you might find that you get used to it. Some drivers and bulbs now support dimmers which is another option perhaps, most reputable stores will accept a return of the dimmer doesnt work with your light fitting

Justin Foss said...

Thanks for the reply.

I mean can I leave the centre bulb on each row in the holder so they look like the other bulbs but then not have the two prongs on these bulb pushed into the connector.

Mr Ives said...

Sorry Justin for not getting back to you earlier.

Im still unclear why you would want bulbs in the fitting but not connected ? However if the pins are not connected then fine, but my concern would be that if you connect but slightly pull out the hulbs till they go out, this would not be safe. Rather likel partly unscrewing a Screw bulb to make it go out, you may get some residual arcimg or sparking which over time could present a fire risk. If your bulb holders enable you to put a bulb in but have no connection to the electricity behind, that would seem fine, but if you are relying on a partial connection , then id suggest not. Of course you could fine two failed bulbs where no circuit exists within the bulb, they should be OK ? However i return to my original point, wouldnt a fitting with some bulbs off look just as odd as one with several bulbs absent ?

Paul fisher said...

Hi Mr Ives

I left this blog back in november with no reply. Could you please consider?

Hi,

I have changed 8 x MR16 50W bulbs for 8 x 5W (80 SMD) LED's. Each light has it's own transformer with a load range indicated at 10-60W. They are all working perfectly even though they are less than the minimum load. On the basis that they are working OK, is this safe re the transformer?

Mr Ives said...

Hi Paul, sorry if i didn't reply before.

I cannot absolutely confirm its safe, I'm not an electrician, just a diyer, however i suspect its fine. My experience is that if the transformer has an issue with the load it will either blink once, strobe or not come on at all. If you have the lights working, its seems like the transformer,mor rather the power supply to be correct, has no problem with the load or that the load is within its load range.

Anonymous said...

Hi Mr Ives ,
I'm looking to change the MR16 bulbs in my shower room, to LED bulbs,
My transformer is Halolite Model HA SE60 20-60w/va inductive load compatible, 1.0 kv surge protection
Prim 240v 50-60hz 0.26A
Sec 11.4v. Off 5A
Cos =0.98
ta50c to 75c
Sorry for all the info if not required.
At the moment my MR16's are 50W is my transformer ok to use each of the 4 lights has it's own transformer.
I also have 10 240V GU10 bulbs in the kitchen that I would like to change.
Thanks Mike

Mr Ives said...

Hi Mike,

I don't think it will work. The minimum quoted load for your transformer is 20 watts, but a typical LED MR16 is going to be about 6. I guess you can try it, but the point of my blog was the realisation that I needed to get a transformer that had a minimum load equal or lower than the bulb I was intending to use

Eugene Tan said...

Hi, I had bought a few MR16 LED with 85-265V AC. I have 2 questions in mind,

1) Do I need a transformer?

2) My current halogen lamps are 50 watts. Can I replace it with LED lamps without changing the halogen transformer?

Note:
My LED specification are listed as below,
Voltage 12V AC
Rated Power 5x3W
Power consumption:5.5-6.5W


Thanks.

Mr Ives said...

Hi Eugene,

1) my understanding is that MR16 bulbs require a 12volt DC supply. Hence the need for a transformer. There are LED bulbs capable of running from a mains supply i.e from 110v USA or 240v Europe, but these are physically different and called GU10. They have bigger lugs on the base of the bulb rather than the pointed pins on the base of an MR16. Im not sure why yours mention that AC range, though it could simply mean a range of AC voltages that can be transformed to DC. so my answer to your question is yes

2) this is harder to say. You need to know what the minimum load the existing transformer will support.,this value is typically printed or moulded on the case of the transformer. If you add up the wattage of all the LEDs you are proposing to connect to a single transformer, is that value lower than the minimum the yransformer supports. If it is lower it probably will not work. If its within the load range it will.

Eugene Tan said...

Hi Mr Ives,

Thanks, I have checked my current halogen spotlight, they are listed as 240V 50Watt without using any transformer, and they are MR16 base.

So now I have a new question. Can I can use direct connect using a LED spotlight with rated 85-265V AC and 12V DC?

http://www.ebay.com/itm/MR16-5X3W-Warm-Cool-White-LED-High-power-Spot-Light-Bulb-Lamp-85-265V-AC-/281328168588?pt=US_Light_Bulbs&var=&hash=item4180772e8c

Thanks again for your answer.

Regards,
Eugene

Mr Ives said...

Hi Eugene,

I see. I had a google and I see there are mains voltage MR16 bulbs.

Well I think the bulbs you suggest could work, but in the description it says they are 12v AC again ? so not very clear. Are you able to ask the seller if they are suitable for mains voltages ?

Anonymous said...


Hi,

I had one halogen lamp (50 watts) in the kitchen. Can I replace it with one LED lamp(4 watts) without changing the halogen transformer? I assume yes since the transformer is providing far more power thoughput than the LED needed. am I right?

Someone said the voltage provided by the halogen transformer maybe only 11.6v and cause the LED lamp dimmer.
If assume I do not care the LED lamp is dimmer, and my questions arise as follows:

1. Am I going to save energy in my case since I did not change the transformer of the original halogen?
2. if the voltage is 11.6v instead of 12v, would this reduce the LED lamp life?

thanks

Mr Ives said...

Hi Anonymous,

Its not quite that simple. The important indicator is the minimum load the transformer supports. We use the term transformer but these little boxes are really switched mode power supplies. They expect to see a minimum load i.e a minimum amount of power before they work. Some power supplies have a minimum of a few watts and are suitable for LEDd as typically one or more bulbs will exceed this. However in your case, say your replacement LED bulb was 4 watts, your need to check if the existing transformer had a minimum load equal to or less than 4 watts.

It should be printed on the body of the transformer. If the minimum load is higher than. An LED then the bulb may strobe, flash or not come on at all.

If you use a lower wattage bulb i.e. lED you will use less energ

Tom said...

Hello, Mr Ives,

Thanks for a very informative post. This question concerns heat, and if McGyver is still lurking around here after a few years, perhaps he has some insight too.

I have seven MR16 20 watt halogen lamps in the ceiling of my kitchen. Above the kitchen is an unconditioned attic space. Due to their non-insulation contact requirements, these fixtures are losing heat to the attic in the winter, and one goal of mine is to eliminate that heat loss.

It looks like most of the LED replacements rely on convection air currents along the heatsink to maintain the electronics temperature. Does this imply that the unit needs airflow up through the mounting fixture? If so, that would still prevent me from allowing insulation contact.

Thanks in advance for any advice you can offer.
Tom

Mr Ives said...

Thanks Tom,

That's a really good question, and I can't really give you a good answer. I have quite a few GU10 (i.e. 240v) halogen light fittings and a number are in the ceilings below my attic. As part of the installation, "top hats" made of heat resistant material were installed above each fitting to prevent insulation touching the back of the fittings and overheating, starting a fire. These hats are made from a yellow soft material, almost like fire blanket. Now each one is about 60mm tall and has vent holes in the top . They are designed to cap each recessed fitting and allow insulation around them BUT not to be covered. Now when I went to LED bulbs the energy consumed and heat generated dropped after the LED bulbs were swapped in for the halogens, but they still get quite warm.

Personally I'd be uncomfortable sealing over these recesses with insulation, even though I guess I loose a fair bit of room heat through the recessed holes. I'm not sure if the LED's are a fire hazard, or as you imply, if blocking their air flow will cause premature failure ? Either way I haven’t changed it since then.

Now I live in the UK where we don’t experience extremely cold winters and I don't live in an Eco home with massive insulation. My house is 80 years old and some parts are cold and inadequately insulated. Hence I can live with me ceiling holes venting heat.

Not really an answer, I think you'd have to ask an electrician .

Mr P said...

I am hoping somebody can help me! I have 3 12v lamps in my unused fireplace which are on a 12v system. A short while ago they all went out together. I replaced bulbs just to check not that but as all failed together I suspected it wasn't, which was the case.
I have check current and there is a current coming out of the transformer and current getting to each of the lamp sockets, which are the mini two pin type.
I have tested using a tester screwdriver and not a proper meter.
Any thoughts on the problem?
Thanks

Mr Ives said...

Greetings Mr P,

It does rather sound like the power supply, while providing current is not providing sufficient voltage.

If you have access to a multi meter you could try checking the voltage across each bulb, which should be 12volts or higher. If its not you may have to replace the power supply, which is what i had to do in my blog, they are not too expensive.

light bulbs said...

Hi Mr. Ives!
great post, I actually get asked this question a lot so kudos for writing this up and the photos. Question though, did you buy a seperate LED driver and put that between the existing transformer? or did you replace it with the led driver?

Mr Ives said...

Hi,

No the new driver replaces the old transformer. We refer to them as transformers though in fact they are all switched mode power supplies. Transformers have a large metal laminate cored piece inside and they are rarely used due to expense. The SMPS is ubiquitous now as they are cheaper and smaller.

So to answer your question the LED driver replaces the old "transformer" and its function is to convert mains AC to 12v DC