LED wedge-base bulbs for landscape lights

Hello, new member here ... I ended up here because it appears there's a lot of knowledge about LED lighting, including folks that are doing DIY stuff with discrete LEDs. My issue is that I am installing landscape lighting (aka. low-voltage lighting); IOW, lights out in the yard, along the driveway, etc, that run off of 12v. So I figure there's a lot in common with automobile lighting, though I think the color quality might be more important to me. The problem is, no one seems to make 12v wedge-base (aka. miniature wedge) bulbs where the color quality is worth a damn. Even the ones that claim to be "warm white" tend to look like crap, usually with a kind of yucky greenish tint. I've tried Zonetech and Brigthtech ones from Amazon (you know your odds are poor when the product page does not even list the color-temp or lumens), and also from superbrightleds.com.

I've come to the conclusion I have to DIY these bulbs. It seems pretty clear that Cree is the company that makes LEDs with very-high quality light. I'm not sure where to go from there. A lot of DIY links talk about just putting 4 or so LEDs in series and hoping for the best. Maybe that would work. But Cree actually seems to make some "high voltage" LEDs, that seem like maybe they could run directly off 12 volts:

http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Discrete-Directional/XLamp-XTE-HVW

Brightness seems to be in the 100 lumen or so range (which is exactly what I'm looking for), at about 1 watt or so, and with CRI of 80+. The issue, I guess, it since I'd be controlling voltage directly, but current and therefore lumens indirectly, would the brightness be close enough to what I want; and more importantly, would it be consistent from light to light within a group (say the 10 or so along the edge of my driveway) ? Seems to me like their "binning" procedure, would deal with this. Anyhow, it all seems too simple in a way (for example, most places talk about needing an "LED driver" which provides a constant current to the LED), and I wonder if anyone else. has tried these for 12v applications.

Thanks.

Ah well, I actually located some that don't look half-bad, so I guess I'll drop this project for now. In case anyone else on the same quest stumbles across this thread, here's what I got:

http://www.amazon.com/dp/B009DRF3VW/?tag=cpf0b6-20

.. and cheap at 10 for $25. They are VASTLY superior to some ZoneTech ones that I also bought at Amazon. And they look just as good as a WLED-WWHP15-TAC for $7 from superbrightleds.com. Time will tell if they last well.

Be careful, most outdoor 12v lighting is A.C., or at best, poorly rectified D.C.
LEDs do not like that very much.

FRITZHID said:

Be careful, most outdoor 12v lighting is A.C., or at best, poorly rectified D.C.
LEDs do not like that very much.

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They seem to work fine off my 12vac transformer, and people in the Q&A at the Amazon page say they've run 'em off 12vac for several months with no problems. Also, the flicker with these is virtually un-noticeable, not so with the ZoneTech ones. I hope I don't come off like a shill for the Brightech bulbs, I'm just really kind of ecstatic, considering I thought I was going to have to build my own bulbs (per my OP).

I don't quite see why bulbs wouldn't work on AC, the main issue is that the LED diode is reverse-biased half the time, but I don't think many diodes have a reverse breakdown voltage anywhere close to 12 (or 16) volts. Unless LEDs are different somehow.

But I also don't see why the transformers don't spend a few extra bucks on a full-wave bridge rectifier (for a product they sell for hundreds) and eliminate any concern on this account. I myself am tempted to add one to mine:

http://www.jameco.com/1/1/7753-26mb80a-25a-800v-silicon-bridge-rectifier-diode.html

.. for example, and a capacitor.

That would be my approach. A full wave rectifier and a couple of 2200mF caps to clean things up. It's a cost effective fix vs. buying a driver.
I only posted as a caution. As anyone knows, sometimes electronics can be twitchy, lol.
Not to mention, I personally have an aversion to A.C. flicker and endeavor to eliminate it to the fullest of my ability.
Even with modern pwm lights, movement seems "stroby" to me and drives me nuts!!

FWIW, half wave rectification, such as running the diodes off straight AC without reversing half of them, will give you a 60Hz flicker. Other techniques like full wave without filtering will give you 120Hz instead and a lower contrast ratio. That can make a big difference all by itself.

inetdog said:

FWIW, half wave rectification, such as running the diodes off straight AC without reversing half of them, will give you a 60Hz flicker. Other techniques like full wave without filtering will give you 120Hz instead and a lower contrast ratio. That can make a big difference all by itself.

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Correct, and filter caps clean that up even more.
That ½ wave rectifier flicker is migraine inducing as all hell! Lol

As far as flicker, I didn't think about it much, until I went to replace the ZoneTech bulbs ($1 at Amazon) with the Brightech ($2.50 at Amazon); I usually switch 'em "hot", and I was like "holy cow, these (Zonetech) have a lot of flicker" and "wow, the flicker is WAY less noticeable with these (Brigthech)".

It really is pathetic they don't put a rectifier on the damn transformer; but I guess when they were designed, LEDs (for lighting) were not much on folks' radar, so there was no earthly reason to think AC wouldn't be fine.

I don't see why flicker from half-wave rectification would be any worse than flicker from just running off AC - but maybe that wasn't what you meant.

I checked these Brightech bulbs out under a magnifier, and they have an LM317 in them (linear voltage regulator which also can be configured as a current source). I can't quite reverse engineer the circuit, but there seem to be 4 diodes between the input contacts and the LM317, so I'm thinking maybe these babies have a full-wave rectifier built-in. That's pretty cool. I still wish the light was warmer, but at least it doesn't have that sickly green tint.

Ahhh! Yes, the lm317 is a regulator, and will to some extent clean the power to the LED, that makes things much nicer than would be without it. I was under the impression that the LED bulbs were just that, an LED with a resistor to make sure 12v source didn't cook it.
Actually sounds like a well thought out replacement for those style (old school landscape lighting) systems.

FRITZHID said:

Actually sounds like a well thought out replacement for those style (old school landscape lighting) systems.

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Yeah, except why the heck didn't they use some of the beautiful Cree LEDs - like I said, though these don't have the pukey green tint, they could be a lot warmer. I'm tempted to try to retrofit some Cree LEDs into these bulbs - but it's mighty miniature.

I'm still intrigued by making my own that are just a single Cree LED, period. Like wiring a string of lights in series and supplying a constant current to it. Problem is, I have strings of 8 and of 9 lights along the driveway, and the lowest forward drops I see in the "lighting class" Cree ones is a little below 3v. So I couldn't start with the 12vac from the transformer, unless there's a current regulator available that can actually step up the voltage.

RustyShackleford1 said:

Yeah, except why the heck didn't they use some of the beautiful Cree LEDs - like I said, though these don't have the pukey green tint, they could be a lot warmer. I'm tempted to try to retrofit some Cree LEDs into these bulbs - but it's mighty miniature.

Think about that que$tion. "Why don't they u$e CREE® LEDs?"
Lol



I'm still intrigued by making my own that are just a single Cree LED, period. Like wiring a string of lights in series and supplying a constant current to it. Problem is, I have strings of 8 and of 9 lights along the driveway, and the lowest forward drops I see in the "lighting class" Cree ones is a little below 3v. So I couldn't start with the 12vac from the transformer, unless there's a current regulator available that can actually step up the voltage.

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Making you're own isn't that bad but they're allot of variables to take into consideration.
1st being,
how much, of what color/cri/cct, etc, do you want/need)
What can you spend on this (time/$).
What do you have to work with.
How much modification are you willing to tolerate.
It the ultimate end worth more to you than buying a whole new system that's up to date and possibly high end?

From there, the possibilities are endless.

I am installing landscape lighting (aka. low-voltage lighting); IOW, lights out in the yard, along the driveway, etc, that run off of 12v

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If you are installing from scratch, could you use ready-made fixtures ? I've have some Malibu LED low voltage landscape lighting fixtures from Home Depot (look for the green packages). The "Charcoal Brown/Equinox" pathlight has a nice warm-white color and a decent light output for just 0.6 watts. I forgot what type of LED that one has but the floodlights that comes with the set have Crees in them.

http://www.homedepot.com/p/Malibu-L...C-_-NavPLPHorizontal1_rr-_-NA-_-203202196-_-N

I have Sylvania LEDdriving wedge base 194/168/2825 bulbs which are pretty bright but are cool white color. They're not polarity sensitive (will work both ways in the socket) but I have not tested them on AC yet (My Malibu lights actually operate off a 12 volt battery charged by a small solar panel)

I'm not installing from scratch, rather, upgrading some Nightscaping (discontinued, high quality) fixtures. I don't mind paying for high-quality LED bulbs, but I can't find 'em (the $2.50 ones I just got from Amazon look as good or better than a $7 one I got from superbrightleds). Yeah, apparently there are new fixtures with LEDs hard-wired into them. Sounds like people are saying Malibu does, but I thought I'd heard Malibu is pretty low quality; Cree pointed me to Aurora Lighting, which also hardwires, but the quality looks very high and I imagine they're very expensive. Anyhow, like I said, I just want LED bulbs for my existing installation.

I am, however, willing to go to a good bit of trouble to make some great LED bulbs (per my OP). I'd even reconsider wiring some of my fixtures to be in series rather than parallel (really just means pulling two wirenuts loose at each fixture and redoing 'em).

Malibu's quality does vary between models but the particular fixture I mentioned earlier seems pretty solid to me. You'd have pick through the ones at the store and get a "feel" for them.

I was going to mention this http://www.amazon.com/dp/B00OCX0AH4/?tag=cpf0b6-20 which I also found at Home Depot but it is for a G4 halogen bipin socket and you mentioned wedge base sockets. I wonder if one could pinch the contacts together with needle nose pliers on a T3 wedge base socket to hold a bi-pin module.

Certainly not an expert on outdoor lighting, but I've got a pretty decent set of lights for the front pathway. Most likely you have 12V AC as other have mentioned. I think it is the T5/T10 wedge you are looking for.

I got really tired of replacing the incandescent bulbs that wouldn't last very long at all. I even spent a good amount of money on some that claimed to be 10,000 hour xenon bulbs. They did last about 2-3 times the life of the regular 1,000 hour bulbs but not much more than that. Then they started going and I decided it was a waste to keep dumping money into these lights. I started the search for LED lights. Like you I was concerned with two thing - a warm white that is truly a warm white and a decent rectifier setup (full-wave and opposed to half-wave) to avoid terrible flicker.

I am not sure how you use your lights, but my purpose is for accent lighting and basic walkway illumination. Very subtle and not high lumens. I was using the 4 watt incan prior to the switch - just enough to see and provide a little light. After searching for a few weeks I found this LED drop-in http://www.amazon.com/gp/product/B005NYRN62/?tag=cpf0b6-20 and I have to see I've been very pleased with the results. I've been running them 24/7 since November 2013. There is no flicker, nice incandescent warm tint and I haven't had a dead bulb in well over a year. At $22-23 with free Prime shipping for a 10 - pack they are also cheaper than the $26+$12 shipping I paid to the Attic Trunk for the supposedly super long life incandescent bulbs.

yuandrew said:

I was going to mention this http://www.amazon.com/dp/B00OCX0AH4/?tag=cpf0b6-20 which I also found at Home Depot but it is for a G4 halogen bipin socket and you mentioned wedge base sockets.

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So how does it look ? Pretty expensive though. My landscaper friend, who got me into this, says there's an adapter that lets you plug a bi-pin into a wedge, but it ain't that cheap.

ShineOnYouCrazyDiamond said:

Most likely you have 12V AC as other have mentioned. I think it is the T5/T10 wedge you are looking for.

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Correct on both counts.

I am not sure how you use your lights, but my purpose is for accent lighting and basic walkway illumination. Very subtle and not high lumens. I was using the 4 watt incan prior to the switch ...

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Same here, except my fixtures orginally had 16watt incandescent, and I'm not sure I'd want quite as dim as 1/4 that.

I found this LED drop-in http://www.amazon.com/gp/product/B005NYRN62/?tag=cpf0b6-20 ...

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That's funny, those look VERY similar to the ones I linked in post#2 above. Actually, the ones in your link and my link look identical. But the ones I received say PB0377, whereas the ones we both linked say PB0081. Which do the ones you were shipped say ? I wonder if there's any difference ? If your's are PB0081 instead of PB0377, we should exchange a couple with each other.

I'm trying to reverse engineer, but it sure looks to me like 4 diodes closest to the contacts, plus a capacitor, forming a full-wave rectifier (why we both see, as you said, no flicker), then the LM317 configured as a current source using a resistor. Is the resistor on yours labeled 22R0 like mine ? I'm pretty sure that means 22 ohms, which causes the LM317 to source 57ma. The LM317 output appears to go to two parallel strings of 3 LEDs in series (which makes sense if the LEDs each have the typical 3v forward voltage, plus 3v or so of required voltage drop in the regulator). So I'm going to try replacing the 6 LEDs with one of Cree's that's a real "warm white", if I can figure out which one.

RustyShackleford1 said:

So how does it look ? Pretty expensive though. My landscaper friend, who got me into this, says there's an adapter that lets you plug a bi-pin into a wedge, but it ain't that cheap.

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Color is a nice warm white and it does appear comparable, maybe slightly brighter than the 10 watt halogen it was meant to replace. I did an indoor beamshot using an Intermatic Malibu CL086AB fixture (*Now Brinkmann Malibu 8308-9103-01) for a host. I posted an Amazon.com link as they are not on Home Depot's website yet but I did find them in the Home Depot store for $5.97. I'm not aware of any adapters that would go from a wedge to a bi-pin socket though other than replacing/modifying the existing wedge socket or fixture.



*Intermatic dropped their consumer products, including the "Malibu" line of outdoor lighting products in 2009. Home Depot or one of their vendors later purchased the "Malibu" name and designs to use on landscape lighting products sold in Home Depot stores. Most current fixtures are actually made by Brinkmann corp

Thanks for the info.