LED bulbs & UL approval

[BretMan]

Hello,

I need to first confirm that LED lights, the inexpensive kind often found in blinking toys are not all that fragile should they have impacts. I know that incandescent light bulbs used in cars still work fine after a high speed accident and those lights are being replaced by LED bulbs now. Is there a rating spec on LEDs to find out about this, I need them to repeatedly survive at least 50 Gs (which isn't that much really). Second, where can I find them?

Also, do most battery operated (6v) hand held devices like flashlights, portable radios/players etc. need to get UL approval or is UL for higher voltage appliance type products?

Thanks.

Bret

Miami,FL USA

 

[VEBill]

Your local $1 store should have some hard rubber balls that begin to blink (internal LEDs) when bounced off a hard surface. I can only guess, but a hard bounce like that must be at least 100G. In other words: yes, most LEDs can easily survive 50G.

I didn't think that incandescent bulbs had a reputation for surviving high speed car accidents (?). Investigators are known to examine filaments to determine if they were on or off at the instant of impact.

Battery operated toys don't need UL But beware, they may need CE if sold in Europe.

 

[IRstuff]

Most LEDs are literally solid state; the LED die is wirebonded to the two connecting posts and the entire assembly is encapsulated in a clear plastic or acrylic. Short of smashing it with a hammer, they are quite robust, and far more robust than any incandescent bulb.

As for where, it depends on what specific type you want. There are dozens of form factors, colors, etc. Radio Shack or Frys would have the canonical LED bulb.

These are a bit pricey, and a little bit less robust because they conform to the glass reflector MR bulb form factor, but they contain 12 SMD white LEDs. You can also search for MR11 LED on EBay and see a few varieties of that configuration.

Just focusing (heh) on white SMD 5050 LED-based products there are thousands of listings on EBay.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[LionelHutz]

The LED itself should not be an issue. You'll have to pay attention to the board design and the quality of the soldering though. I have a LED trouble light and the LED's survived dropping it just fine, but 4 of them fell off the circuit board.

 

[MacGyverS2000]

As Lionel said, LEDs will survive long after incandescent filaments have given up the ghost (cold filaments survive better than hot). But unless you encase the entire assembly in potting compound, your area of concern will be the mounting points of every component in the assembly.

What problem are you trying to solve? Giving us useful information helps us provide more useful info in return.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[BretMan]

Thanks to you all. Great tips too.

I wanted to be sure I wasn't going to run into problems with them failing before going to the trouble of all the design work. I'm relived to know I can go ahead. I'll follow up on your recommendations and if I have more questions, I'll let you know.

Bret

Miami,FL USA

 

[BretMan]

Ok, here's an important question, so I'll know what to ask for.

The application will include being used outdoors in daylight. I need the LEDs to be as bright as possible. They will be powered by a 6v button cell battery. I also need the LEDs to be the lowest possible cost and draw as little an amount of power as possible.

How is the brightness measured - Lumens? Is that the spec to look for?

What would be the category/type name for these LEDs? I know there are new high efficiency ones but don't know if they would meet the above criteria.

Bret

Miami,FL USA

 

[IRstuff]

Lumens or lux or mcd. LED suppliers like the latter one because the numbers wind up being larger. "It's like having an 11 on your volume control."

"outdoors in daylight" How much so, i.e., sunlight readable? That would take a lot of doing, but green LEDs might be the best choice.

"powered by a 6v button cell battery" For how long? Button, or coin, batteries are designed for extremely low current draws, which is not usually in the realm of LEDs. At 20mA draw, you might get a couple of hours from a typical button battery.

The "High Brightness" LEDs are generally the brightest:

http://www.cree.com/products/pdf/LEDlamps/C503B-BAS&BAN&BCS&BCN&GAS&GAN&GCS&GCN.pdf

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[VEBill]

Basic info on light:

http://www.handprint.com/HP/WCL/color3.html#photounits