Anyone seen these? CFL GU10 retrofits

[Zelandeth]

Two links to pages on Maplin's site. Bulb only and one with the fitting too.

Direct replacement for a 40W GU10 halogen lamp, but rated at 7W.

It'll be a 180º flood thanks to the large emission area of the tube, but I imagine that the lower heat output will be of great interest in some cases.

I'm gonna grab one anyway just for curiousity's sake, and because it's an odd looking sucker, and I think it's worthy of addition to my collection especially as I specialise in CFL's and HID, though my knowledge base and collection are both still somewhat lacking.

Here's the links:

Bulb Only

Bulb and Fitting

And I appologise in advance for the *abysmal* typing here, I'm at a friend's house at present (and have been for the last week - hence that I've been quiet...like anyone noticed...), and this keyboard has a distinct Milton Keynesian accent, and is having severe issues with the Aberdonian user!

[Chris M.]

Havn`t seen that particular variant in person yet but thanks for the notice, I`ll have to add one of them to the bulb collection here too very soon. I`m sure I have seen them in Lighting Equipment News though, nice to finally have a consumer-ish outlet.

I did find this interesting one at a local wholesaler though, already posted it somewhere here on a vaguely related note. Uses a CCFL spiral tube and emits a cold daylight-colour flood:



The unit is rated at 5 watts and supposedly puts out an incandescent equivalent 25 watts at 4000K colour temperature. It appears colder than that due to the use of a dichroic reflector, an odd choice that reacts badly to the large light-emitting area and makes the light appear more blue-tinted. An Alumimum coating would have been a better choice but presumably the dichroic was chosen because of heat-related issues. Still, interesting and surprising to find one in our local AM-Lee Electrical too.

Sorry I don`t know where else to find them, and am not even sure the place that one came from still has any.


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[Zelandeth]

Okay...gonna go try to pick one up tomorrow. Probably won't be able to play with...er...test I mean it or photograph it properly until Wednesday, but will try to get something done...

Hope you realise you guys are responsible for me having to walk from the Centre to Winterhill in the cold now...

Interesting looking thing there Chris M., How much did that one retail for?

[Chris M.]

I don`t remember what that one cost, think it was about £6 - 8 plus VAT. If you`re interested in one I could pop in there sometime next week and see if there are any left.


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[Chris M.]

I ordered one of the Maplins CFL GU10s on the week-end. Also noticed they had another almost identical one sold as "bright white" which was a little bit cheaper and of course couldn`t resist. They arrived today. For those not familiar with the GU10 form factor, it is a 240 volt mains powered light with a twistlock base similar to fluorescent tube starters, intended as a low cost transformerless equivalent to the common 12v MR16 reflector spotlights and often found in recessed celing downlights. GU10s are also commonly found in surface mounted directional spotlight fixtures where the lamp body is minimal and the glass reflector portion is exposed. Usually halogen lamps with aluminum reflector coatings and beam angles of around 60 and 120 degrees. Given the fact that they are often found in downlights, they have to be no bigger than a certain size which is the same diameter as a MR16 but a little taller to accommodate the larger lamp capsule and base.

These fluorescent retrofits are the same diameter as regular GU10s but bend the size rules by being taller by around a half inch. Necessary to accommodate the tubes and ballasts. They are also fatter around the middles, again due to the insides. I don`t have any proper GU10 fixtures but expect these to protrude out from the end of an enclosed downlight, while in a surface light they will fit just fine but be a little bigger looking. The tubes are constructed of four J shaped sections joined to form a W (or M) shape, and stacked one on top of the other. The body and lens is plastic with a silvered reflector surface inside around the tube to maximise the light output.



On the left is the 2700K warm white one as in the original link. On the right is the 4000K version, order code N79BR. For some reason the warm white one has a clear lens/reflector with translucent body and the 4000K one is a little more "professional" looking with mildly frosted lens/reflector and white body. They both came in the same purple Pro-Tronic package. As with other modern CFLs they light instantly and silently, and take a minute or two to reach full brightness. The light is a wide flood and side by side I would have to say that when warmed up, the 2700K one appears a little brighter. I don`t have a 40 watt GU10 to compare with but just going by ordinary 40 watt reflector bulb standards, it`s close, definately. Admittedly I don`t have a 40 watt reflector bulb avaliable right now to compare to, it`s usually pretty dark in here anyway, but I`ve been staring at lights all my life and it looks good to me.

Underexposed head-on shots, 4000K on the left, 2700K on the right:



A closer look at the tube inside the warm/clear one:



Interesting lamps and worthwhile CFL replacements for the hot and less efficient tungsten versions. Not hugely directable so probably more suited to downlights giving area lighting, and of course they can`t be dimmed or powered via electronic control gear. Despite being slightly dimmer I prefer the 4000K lamp, its output is a little smoother and appears to be slightly higher quality overall. Still noticeably warm compared with daylight though. The other one is definately trying to appeal to the current "designer" market with its translucent blue body and is definately distinctive as well as efficient.


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[Chris M.]

I just noticed something. The 4000K light has its tube made from four J shaped sections joined together, while the 2700K one is made from two sections of tube that were formed into a U shape then bent over again and joined together at the ends. Makes me wonder if one is a slightly older version.

Also noticed on the packaging that the 4000K one claims to consume 50mA while the 2700K one consumes 61mA. Both are still rated 7 watts. Obviously both over 7 watts if you do the math based on a supply of 240 volts, probably the actual rating taking into account ballast losses. That would imply the 4000K one is more efficient, or explains why it is slightly dimmer (lower tube drive power).

Interesting...

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[Zelandeth]

Interesting, very interesting. As it turned out, the MK Maplin had sold out...right that morning when I was on the way in. Grrrr....

Will order one tomorrow from the website now I'm home again.

And Chris M., feel free to go grab one of those if you're in the area, don't go out your way if it's a problem, but I'm curious, as always.

Good photos as usual, certainly an interesting looking thing. Spotting things like this in retail outlets usually gets me funny looks as I suddenly stop in the middle of nowhere and start staring upward at a light fitting...but that's what this sort of interest's all about. Especially the seeing spots afterward...

[Wim Hertog]

</font><blockquote><font class="small">Als antwoord op:</font><hr />
Chris M. said:
Also noticed on the packaging that the 4000K one claims to consume 50mA while the 2700K one consumes 61mA. Both are still rated 7 watts. Obviously both over 7 watts if you do the math based on a supply of 240 volts, probably the actual rating taking into account ballast losses. That would imply the 4000K one is more efficient, or explains why it is slightly dimmer (lower tube drive power).

Interesting...

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[/ QUOTE ]

You can´t just multiply Volts x amps in this case because the CFL´s don´t have a power factor of 1 (probably 0.55-0.60).

The correct formula to calculate the real power consumption is U x I x cos phi -&gt; 240V x 0.050A x 0.55 = 6.6W

[Zelandeth]

Hmm, depends on the brand I guess. I'd certainly expect any decent modern CFLs to include PFC hardware of some kind - otherwise you're kinda defeating the purpose of the object - efficiency. I don't have the hardware to measure power factor here, but the two lamps I did see the datasheets for at some point (Osram Dulux range if I remember rightly) were in the range of 0.8-0.9. Will see if I can dig the sheet out again. Haven't seen it in at least a year though...so no promises that I'll be able to find it!

[Wim Hertog]

I thought the Osram dulux "economy" series had a low power factor and the "longlife" series were power factor corrected....most CFL´s today are low power factor because the PFC circuit is very expensive. Allmost all CFL´s (except expensive ones, like the dulux longlife) use a ballast built with discrete components...a PFC circuit is almost always in an IC package &lt;- expensive.(I know this rather well because I´m in the business)

A low power factor makes the CFL less efficient, true...but the power factor has no effect on their electricity bill, and that´s what matters for most people.

[Zelandeth]

Got mine today, interesting little thing...way smaller than I thought, and now officially the smallest flourescent tube in my collection.

Interesting to see that these tubes have quite an amount of mercury in compared to most fluorescents (or at least I think so), it's contained in a small capillary (shown on the bottom branch in Chris M.'s previous post, not sure what the reasoning there is.

Overall light output does appear to be consistent with its claims. I compared it to a 50W MR16 halogen, and this was very slightly dimmer overall I'd say.

A local hotel owner has asked for my help in upgrading the lighting there (Probably something due to his electricity bill coming to around £250/week) - and I showed him this. 25 50W MR16 halogens will shortly be getting replaced with these. A reduction from 1250W to 175W, just by replacing those.

[brickbat]

Why would a poor power factor affect a lamp's efficiency? Efficiency is lumens/Watt - Poor power factor increases the VA of a load, but not its power (wattage.)

BTW - my sampling of CFLs has shown them to have PFs of about 0.5 - 0.6

[Wim Hertog]

</font><blockquote><font class="small">Als antwoord op:</font><hr />
brickbat said:
Why would a poor power factor affect a lamp's efficiency? Efficiency is lumens/Watt - Poor power factor increases the VA of a load, but not its power (wattage.)

True, but the power plant consumes more fuel because it has to deliver more current for the same power...correct me if I´m wrong. And that´s "real" efficiency....

[brickbat]

OK - I can agree with that - PF has nothing to do with a lamp's efficiency, but when you look at the entire system, a poor PF will cause higher drop in the transmission/distribution system voltage, thus reducing the efficiency of the transmission/distribution system.

[Zelandeth]

Okay, running data on this lamp:

Actual power useage: 7W.
Apparent power useage: 15VA.
Power Factor: 0.48.

Had mine running for a few days now, and it seems to be doing just fine. My 24/7 CFL testing area's presently occupied, so I can't put it in there just yet. Might add a socket there for it later though.