Request for Design-Build Assistance

I have a need for about a dozen battery-powered LED array modules to be used to uplight plants being used for centerpieces. Each array would likely consist of up to ~6 super bright narrow beam white LEDs, arranged in a circle with an opening so it could be slipped around the trunk, w/any battery of choice that would be small and concealed. It would be desirable to have something to control spill light so people sitting at the table won't be distracted by glare. These will be used once, and need to be powered continuously for ~10 hours. Most of the preconfigured LED arrays or LED light rope either aren't the right size or are too expensive for one-time use.

I'm a HS teacher and handy with a soldering gun, but just don't have the expertise to be able to see this through in time. If any of you are looking for a project and are interested, feel free to email back-channel w/contact information.

Thanks in advance for your interest!

Mark
mgatof[nospam] [at] juno

[LEDependent]

NO! You're just contributing to light pollution if this is outdoors! I like the stars...

[wasabe64]

Hi Mark,

Welcome to CPF. [img]/ubbthreads/images/graemlins/wink2.gif[/img]

It would be possible just to direct-drive a string of 6x5mm LED's with D-cell batteries to be truly cost-effective. If you wanted a current-regulated or boost circuit one of the Shoppe's BadBoy or DownBoy convertor boards would be suitable.

There are many members of CPF that can help you, but may not notice this post in this forum.This question would be better asked in the LED, Electroluminescent and Lasers forum. The forum you have posted in is mainly for questions pertaining to the components being sold through the Sandwich shoppe. The LED, Electroluminescent and Lasers forum gets a lot more traffic.

I suggest that you contact one of the admins via PM (Sasha, Roy, Empath) to have this thread moved to the LED, Electroluminescent and Lasers forum.

[drs2000]

Looks like an interesting project. No need for fancy stuff.

I'd suggest this as a source for your white leds cheap and decent. I've purchased a few thousand LEDs from this guy and he's been great.
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=2594583740

Look at his other items for sale if you want 5000mcd whites or anything else. No shipping charges and he's pretty fast..

What is the space you have available? (How big is the plant around, how tall. How much space for batteries.)

Can you just bury a battery pack in the plant soil? (Use heavy-duty Ziploc bag.)

I did a one-shot thing like this before, where I used shirt cardboard, punched with a small awl, poked LEDs thru and bent the LED upwards, and the backside leads left/right and wired ut that way. Use a 3" high strip of cardboard/matteboard long enuff to run around the inside of the container/pot on edge. Hopefully the bottom at least an inch below the lip. Adjust the dimensions to suit. punch tiny holes near the bottom edge and thread LEDS thru from the inside surface. Bend LED upwards. The excess cardboard above the LED can be your glare shield. Wire LEDs from the outside, keeping the wires/resistors below the visible level.

Trying to keep this on the cheap, by the way. If you leave the leads on the LEDs long, you can easily recover them.

Trying to think of an easy power source. The easiest, if you have room for it, is the 6V lantern battery, cheapest you can find, and wire LEDS for 6V. each LED in series with a 100ohm resistor to the battery. Not screamingly effiecent, but easy, cheap and able to run the time you want for 6-8 LEDs per battery.

If you don't have the room, or have other options for batteries:

3 alkaline C cells would work. Use 33 to 47ohm resistors instead of 100ohms.
6 AA could work. wire LEDS 2 in series, and use a 68-82ohm resistor from each pair to battery.

Bunch of thots from a flu-ey technician.

Good luck!! If you have any electronics students at the school, you might be able to enlist a bit of help. I'd hate to try to build this remotely..

Hope this helps..

Yours, drs off for more Vitamin C...