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From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.
We appreciate your patience as we improve our online experience.
08-04-2011 02:57 AM
If I remember correctly, lid reflexes are checked by the doctor at an age of several month (2 or 6). The brightness change is similar in intensity as when leaving a room into bright sunlight (the eye is not a good detector, so the uncertainty associated with this experience might be a magnitude). It isn't wise even for an adult to look at the LED when switching it on.
Concerning the spectrum/wavelength, here are the data sheets (Luxeon Rebel) for color (p. 12) and white (p. 11). Both don't have no UV <400nm, but of course blue in the range 400..500nm.
When I'm back to work in 2 weeks, I'll look into this, as I've a book about optical safety from VDE (about non-laser optical radiation). But if I remember correctly, main dangers are from UV. The first white-light LEDs were using UV and a florescence film. However, the UV isn't desired as for general lightening, you'll use some polymers (PMMA) as diffusers, which are damaged by UV as well.
Concerning other dangers, there is a risk of electrical shock (and this is even more dangerous for kids as for adults, as there body resistance is 500Ohm compared to 1000..1666Ohm for an adult). I think toys are not allowed to operated at 24VDC.
Another issue I found was that the heat sinks (got a cheap one) are pretty sharp, so both me and my daughter already got a small cut.
But anyhow, a great toy for adults and kids.
Felix
08-04-2011 06:30 AM - edited 08-04-2011 06:34 AM
@f. Schubert wrote:
If I remember correctly, lid reflexes are checked by the doctor at an age of several month (2 or 6). The brightness change is similar in intensity as when leaving a room into bright sunlight (the eye is not a good detector, so the uncertainty associated with this experience might be a magnitude). It isn't wise even for an adult to look at the LED when switching it on.
[...]But anyhow, a great toy for adults and kids.
Felix
I build a lantern for my 2 year old daughter using 2 AA and a luxeon red LED (harvested from a freescale demo torch together with the battery-holder) and a 40XX? plus FET and a switch for ON-OFF-blinking and a PET bottle .. great success 🙂 and regularly used to light the caverns/dens they build (covered with some tissues makes a nice indoor fireplace).
Best features:
Robust! (as robust a PET bottle can be)
Its rain resistant 🙂
Design can easily changed with a new bottle
After one year in use still the first set of batteries*.
Yeah, great toy for adult and kids 😄 😄
*)The main reason for the circuit was to reduce the brightness of the luxeon avoiding a current limiting resistor. No energy burner in the electronics and surprisingly never left turned on. OK, an auto turn off with motion sensor would be the killer app 😉 )... where is the MSP demoboard .....
08-04-2011 07:31 AM
Thanks gang!
I think Olivia is going to learn about wires (real wires that is) and batteries this week-end.
Ben
08-05-2011 02:53 AM
Here is a very nice article about science toys present and past.
I really like the 'Atomic energy lab' 🙂
08-05-2011 07:37 AM
@Henrik Volkers wrote:
Here is a very nice article about science toys present and past.
I really like the 'Atomic energy lab' 🙂
Those were on my wish-list every year when I was a kid, but my Mother had a rule "Nothing that will blow-up or plugs into the wall (toy train transformers excepted) allowed under any cicumstances!" So I had to volunteer to help clean the drive-in to get a chance to find out what randomly mixed cleaning agents will do.
SpoilerWhich was a good idea now that I look back because that green cloud would probably not have been so much fun if it was inside.
Ben
08-12-2011 09:01 AM
Forum is down this weekend so here a small project for the (old and jung) kids:
light a LED with a DIY battery from copper coins, paper, aluminum foil , salt and vinegar. What a wonderful rainy Sunday project
I additional used a plastik sorting box and paperclips here a scheme:
missed the LED but hopefully you will get it 😄
Have a nice weekend
08-15-2011 01:00 AM
I was thinking about powering a LED with a DIY battery, so kodus to Hendrik for posting the solution before I did ask.
Felix
10-26-2011 08:47 AM
I finally convinced my better-half that she REALLY desrved a Mint (robot that sweeps and mops floors, no not rugs). She purcahsed it on Saturday and after a charge up I put it to work and ws very impressed with it so I ran it four times in sweep mode since it was happy to wander off into those corners that nobody ever sees. But I ran down the batery and had to wait until Sunday to switch to the wshing phase.
So Olivia came to visit while the robot was busy mopping up and I introcuded her to the Mint and she was only slightly curious. Later when it was time to go home I had started another mop-up prior to departure (I really like clean floors). But this put a freshly mopped path between Olivia and the back door. She was hesitant to cross the path but as she did she clearly stated
"Excuse me robot."
Ben
10-26-2011 11:24 AM
Just need that robot to do all those other little chores
10-27-2011 03:23 PM
When my girl was little I took her to work with me after-hours on a number of occasions. She had a blast playing with the prototype board. I showed her how to wire up an LED and that was fun for her as long as it took her to go through all the combinations of all my colors and sizes of LEDs. About 10 minutes. After that she thought it was more fun to make pictures with the multicolored wires. Now she's 30 and a social worker.