# LED low-voltage landscape lighting



## RimfireJim (Mar 25, 2009)

Anyone here have any experience they can share with converting their low-voltage (12V) landscape lighting fixtures from incandescent to LED, maybe with something like these: LED Replacement Bulbs ? I'd like to add some path lighting to my yard, and my estimate of the wattage required for incandescent bulbs is more than I want to have to deal with. I haven't been able to find a light output figure for the typical 7W incandescent bulb to compare with these LEDs.


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## SE18 (Feb 21, 2008)

I actually want to learn how to go the reverse way, as I find the yellower glow more soothing; but I understand your situation is more to see where you're going


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## NavyTech (Aug 2, 2008)

switching to LED is easier than you think. Simple remove the bulb and socket and connect a 750K ohm resister in series with the LED and connect to existing wiring. Here is a simple PDF file that will explain what I mean by series circuit. http://swogscale.com/ckgrs.com/CKGRS/HOW_TOS_files/ELECTRICAL%20WIRING.pdf


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## desertrat53 (Jan 2, 2008)

Because I use on-board battery power, I have connected my Malibu power supply to my rails (installing the plastic connectors to prevent shorting out on dogbones - pretty much as you would on a conventional powered track setup) and then I use rail connectors where my jumper wires lead to my layout (houses, sawmill, etc) as well as the original Malibu pathway lights along the sidewalk. Originally I too faced a power shortage - lights were dimmer that I wanted - so I went to superbrightleds.com and bought their replacement wedge bulbs to use in the pathway lights. Viola!!! Lotsa' light all the way around - my displays are once again as bright as they should be, plus the pathway lights actually do some good now.
Some of the improvement will depend on which model Malibu power supply you use, but with almost any of their units (other than their smallest ones) you should get the results you are looking for. The bulbs simply slide in as the original wedge bulbs do....easy enough. Plus, their expected life means "once and done".


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## nkelsey (Jan 4, 2008)

Replaced all of my area lights with led bulbs and very happy with the result. I use blue for a softer lighting. No more wandering around wiggling the incandescent bulbs in the socket to make contact again..plus no replacing burnt out bulbs...so i disturb the spiders less..


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## Rod Fearnley (Jan 2, 2008)

Okaaaaaaay, I like this idea. So, how do I know what in LED terms, is the equivalent to a 25 watt malibu bulb(Lamp)?
Rod


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## Greg Elmassian (Jan 3, 2008)

need to get light ratings in lumens for each... of course LEDs are more directional that incandescent bulbs, so you need to be sure to find a way to diffuse the led... you can get these specs on the internet, of course. 

Regards, Greg


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## nkelsey (Jan 4, 2008)

I got mine from http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fmalibu.htm

I used the T4M led bulbs to replace the 7 watt malibu bulbs I had around the layout and the T8M bulbs in the fitting I have inside my storage shed. The T4M are brighter than the 7 watt malibu and you can bend the leds to change the direction of the illumination if needed.


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## Rod Fearnley (Jan 2, 2008)

Thanks guys. Link is spot on Nick. I shall have to do a bit of local research for the same LEDS here in the UK.
Rod


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## aceinspp (Jan 2, 2008)

I just replaced all my bulbs with 4 watt and they work fine for my purpose. Later RJD


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## RimfireJim (Mar 25, 2009)

Thanks, Nick & desertrat53- that's exactly the kind of experience I was asking about. Your link is the same one I posted in my original message, and those are the replacements I was considering. Looks like I should order a few and stick them in some Malibu lights I've had sitting on the shelf in the garage for, oh, ahem, about 20 years.









Navy: it's easier than YOU think. These are direct, plug-in replacements, no additional resistor necessary. 

Greg: I already tried that route, with no luck. You're "of course" implies that it should be easy to find the specs, but even after a lot of searching, I couldn't find them for the 7W incandescents. I finally gave up and asked here for a real-world, experience-based comparison. 

SE18: the company I and others linked offers LED replacement units in warm white, 3200K color temperature, almost identical to the 3000K from standard incandescent lights. The warm whites also have the best viewing angle per LED 

For anyone curious in how this compares electrically, the T4M LED "bulbs", which Nick says puts out more light than a 7W incandescent, run about 0.4W (based on an average of the voltage and current ratings). What baffles me is that the T8M, which has 8 LEDs instead of 4, but with the same intensity per LED, runs only about 13% more power than the T4M. How is that possible? Seems that it defies the laws of thermodynamics, unless the T4M is less efficient.


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## Greg Elmassian (Jan 3, 2008)

Of course was about something different: 

"of course LEDs are more directional that incandescent bulbs, so you need to be sure to find a way to diffuse the led.." 

Was warning you that even if you have the lumens of output, you cannot directly compare the numbers since LEDs are more directional. 

Regards, Greg


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## RimfireJim (Mar 25, 2009)

I was referring to your second of course: "you can get these specs on the internet, of course. ", but that's OK  

Gottcha on the comparison issue. Even the lumens number on an incandescent doesn't tell the whole story, because that is a spherical value and some of the light may go into surfaces where it is absorbed rather than reflected (unless the bulb is dangled from a wire, not a particularly attractive option). And then you have some bulb manufacturers spec'ing Mean Spherical Candle Power, an obsolete unit. Whew! The bottom line is that the best test is a direct comparison _in the fixture in which it is to be used. _ Fortunately Nick and desertrat53 have already done that for me  

Now it's a matter of making sure that there are LED versions of the various bases used in the landscape fixtures on the market that I might buy - there seems to be quite a variety used, depending on the wattage of the bulb. Nothing is simple . . .


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## Greg Elmassian (Jan 3, 2008)

Sorry, you are absolutely correct Jim! Too many of courses! Forgot that the malibu people don't want to give you any concrete data, I was focusing ( no pun intended ) on the LED data... 

On the LED side, some people have sanded the top flush, or even better, drilled into the top, and the "cone" from the drill tip really helps disperse the light, like beaming the light up into a cone with the point down, a circular reflector if you will. 

That's the hardest thing I find with LED lighting, is getting away from the "beam". 

Regards, Greg


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## RimfireJim (Mar 25, 2009)

Malibu seems particularly bad about lack of specs, but even numerous bulb sources I found don't provide any, either. I thought, surely Sylvania would have something, but I didn't have any luck there, either. When I tried to open their Automotive Bulb Catalog, it was flagged as "Games" by our IT dept.'s filter! 

Good tips there on modifying the shape of the plastic housing of the LED. Sounds fairly easy. I'll keep those in mind. 

The directionality of LEDs is why SuperbrightLEDs makes the T4M & T8M units with four and eight LEDs, respectively, in a radial pattern. The warm white LEDs have a 100 degree viewing angle. I don't know how well that comes to approximating the omnidirectionality of an incandescent when used in a fixture that has radial openings only, but it would seem that the T8M would have to come close. I'll find out! 

I'm lovin' this idea, because it looks like the LED option uses only about a 10th, or less, of the power needed for incandescents. There was no way I was going to be able to handle the power I needed, both on the AC circuit and with the in-ground wiring, without going to LEDs. 

Any idea how they can package 8 LEDs to run at 26-45mA total on 10-14V when the 4 LED unit runs 26-37mA at the same voltage and with the same intensity per LED?


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## Greg Elmassian (Jan 3, 2008)

I have found small rectangular ones with 110 to 180 degree dispersion... they were on lighting strips, spaced about every 2 inches. 

Regards, Greg


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