LED Upshooting Outdoor Spotlights?

My brother-in-law in Las Vegas has been infected by flashoholism somewhat -- wants solar-charged led spotlights (mebbe focused with half-round balls) shining up through his trees in the backyard.

So, he bought a bunch of Wal-Mart solar outdoor lawnlights and was thinking of converting them somehow.

I told him if he could find a way of getting the solar charging output up to around 3.5 volts he might be able to buy some Luxeons and install them in place of the Nichia's? I really have no idea, but thought I'd throw this out for suggestions.

you could use the lambda circuit as a step-up, but the solar lights might not provide enough current to drive the luxeon

Agreed, I think he has a problem and may have to go to AC...

I'm playing around a bit with LEDs for shrubbery lighting. Uplighting plants requires quite a bit more light than pathlighting, and the solar units are just barely adequate for that. I've gone to low voltage wired units and put up with slit trenching the lawn to hide the wires.

LEDs on AC can have an annoying flicker as your gaze goes past them. I put a full-wave bridge rectifier (conservatively sized, fused and heatsinked) on the output of the Maibu transformer and fixed that problem. The low voltage lighting wire has one side smooth and the other ribbed that you can use to indicate polarity.

I generally series connect 3 LEDs then use a resistance substitution box and ammeter to determine the correct dropping resistor (varies quite a bit by color and type). Adding a higher PIV diode or two in series with the LEDs is cheap insurance and the forward voltage drop can fine tune your resistor selection. Potting the group in epoxy is best, but I'm experimenting with shrink tubing over one side of the circuit then putting the whole thing in a larger piece of the waterproof automotive shrink tubing with the goo inside. (anybody know a cheaper source than auto stores?)

I had a 12v underwater pond light with amber filter that kept blowing pricey and inconvenient to change MR-12 bulbs. A cluster of Hosfelt bright amber LEDs in the same housing is just as bright at lower current draw. Any color filters really suck up incandescent light, and replacing them with colored LEDs is great. I'm still deciding if turquoise on the bamboo is ethereal or slightly tacky...

Whoa, very info-packed post, thanks. I'm sure it will be most helpful to my brother-in-law -- think I'm gonna get him on this site and let him read the stuff for himself. As a side benefit mebbe we'll recruit another flashohlic!

Yes, it would be a big leap to go from 20ma LEDs to 350ma Luxeons. Solar cells and batteries would run into the hundreds of $$.

Give serious consideration to AC power for outdoor lights.

I recently picked up fluorecent solar lights
Malibu LZ200 It has (4)1000Amp nicad AA in series. How about converting them to led
For $8.00 a light. I have to try

Cold-cathode fluorescent (CCF) technology can be more efficient than white LEDs, producing up to 80 lumens per watt. Where did you find the lights for $8? – I'm amazed they can be sold for that. It would be worth buying some just to play with the parts.

>>The low voltage lighting wire has one side smooth and the other ribbed that you can use to indicate polarity.<<

At these sort of currents speaker wire is also a viable alternative.For tapping into a line, may I suggest Scotchloks, the automotive style cable taps.Allows you to run the line in a big loop in all the useful locations and tap into it at will.

>>I'm experimenting with shrink tubing over one side of the circuit then putting the whole thing in a larger piece of the waterproof automotive shrink tubing with the goo inside. (anybody know a cheaper source than auto stores?)<<

Heatshrink tubing is a standard elctronics supply item, your side of the pond Newark, Digikey and Jameco spring to mind,add www and .com to the names to find them.Other alternative for weatherproofing these type of joints and Scotchloks is either Silicone caulk,bathroom sealant, or self almagamating tape this stuff melts into itself to become a single piece.

Adam

I found the lights at Meijers about a week ago. I feel the same way, a lot of parts.
Do you know the voltage of the LZIWFL Bulb? I don't know any thing about this light except I want to make it directional with 3 or 4 leds. Thanks for any help.
Ron

Ahh!
LZIFLW??? You want to add that to the Acronym List???

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by LED-FX:
....or self almagamating tape this stuff melts into itself to become a single piece.
<HR></BLOCKQUOTE>

Adam,

I've never heard of that tape, it sounds fascinating. I realize that you would probably not know American brands but would it be available in a regular hardware store, and what exactly would I ask for; "Self Amalgamating tape" or is there some other generic term?

Also, If you wouldn't mind describing it in more detail I'd be very interested to know more about it. Does heat need to be applied?

Thanks,
Brightnorm

norm:
Try: X-Treme Tape (self-bonding)
mfd. by VYPAR Products-MOCAP Inc. St. Louis Mo. (800)817.8968 e-mail: [email protected]

That's all the info I have, but I can tell you that once it bonds, the tape's tougher than snot.

Hi Brightnorm,
Self Amalgamating Tape is the usual name for it or PIB Tape,electrical wholesalers might be a better bet or marine or even satellite TV installers.

Its used for sealing joints in high voltage cables in the power distribution industry and a whole lot of other things.Handy stuff in the toolbox at any time.

It cures at room temperature, just stretch it as you apply it to the piece and wrap with a big overlap, it turns into a single piece of rubber in about 15-20 minutes.

Quick glance on Google gave:
http://www.pai-net.com/product/rolltape.html

And thanks to :
http://www.7volts.com/tommytape.htm

you blighters in the USA can get everything better and cheaper than the UK.. ;-)
http://www.tommytape.com/

Which also comes in a load of colours including Glow In The Dark flavour, will be looking forward to someones test on this product, Mr Glow.......

Adam

Adam

Mr. Bulk and others,

I am excited to see that some of you are using the LED's for landscape lighting and other applications. In case some of you would like to start with your lights a little further along than from scratch, I have put together a CPF component offer HERE

- Don