White LED appropriate for illumination?
in [Design]
|
From: Artemus on 11 Feb 2010 17:03 "Rich Grise on Google groups" <richardgrise(a)yahoo.com> wrote in message news:58c8de2d-d513-4b2d-9130-28c4bc047c59(a)e19g2000prn.googlegroups.com... > So, I'm going on a camping trip, and I plan to bring along some > reading material for > the time between sundown and the time when I get bored watching the > stars and > listening to the wildlife until I'm tired enough to sleep. > > So, I need some kind of lamp that's handier to operate than an > ordinary flashlight, > but will illuminate a page of print brightly enough to read > "normally." And I specifically > want a white LED (or LEDs), for battery life - that's another problem > with an incandescent > flashlight, even with fresh alkalines, notwithstanding that stupid > spot - I need more of > a flood, so I don't have to keep pointing the light at the passage I'm > reading. > > I've heard tell of LED bike headlights and the like; what I want is > some wide-angle > "flood" light, that could illuminate an ordinary 8 1/2 x 11 page from > about two feet > (2/3M) away, while I'm at a normal reading distance (18-24" (1/2 - > 2/3M)), brightly > enough that I don't get eyestrain. > > Does anyone have any recommendations, or need more info? > > Thanks, > Rich These were on sale in the local HF store for 3.99 last week. Mine works well although it is aimed too high when on my head. I haven't used it long enough to tell how long the batteries last. http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93549 Art
From: Martin Brown on 11 Feb 2010 17:49 Rich Grise on Google groups wrote: > So, I'm going on a camping trip, and I plan to bring along some > reading material for > the time between sundown and the time when I get bored watching the > stars and > listening to the wildlife until I'm tired enough to sleep. > > So, I need some kind of lamp that's handier to operate than an > ordinary flashlight, One of the headband mounted lights with a diffuser ought to do the trick. You might find it worthwhile bridging the switch with a 470k resistor so you can find the thing in total darkness too. Regards, Martin Brown
From: linnix on 11 Feb 2010 18:09 On Feb 11, 2:49 pm, Martin Brown <|||newspam...(a)nezumi.demon.co.uk> wrote: > Rich Grise on Google groups wrote: > > > So, I'm going on a camping trip, and I plan to bring along some > > reading material for > > the time between sundown and the time when I get bored watching the > > stars and > > listening to the wildlife until I'm tired enough to sleep. > > > So, I need some kind of lamp that's handier to operate than an > > ordinary flashlight, > > One of the headband mounted lights with a diffuser ought to do the > trick. I prefer to mount it on my chest. It creates a more even lighting as well. I use it for home camping, when my companion is asleep. > You might find it worthwhile bridging the switch with a 470k > resistor so you can find the thing in total darkness too. Good idea, but I think a smaller resistor would be better. Even 47k can last a very long time. > > Regards, > Martin Brown
From: Michael A. Terrell on 11 Feb 2010 21:27 Rich Grise on Google groups wrote: > > So, I'm going on a camping trip, and I plan to bring along some > reading material for > the time between sundown and the time when I get bored watching the > stars and > listening to the wildlife until I'm tired enough to sleep. > > So, I need some kind of lamp that's handier to operate than an > ordinary flashlight, > but will illuminate a page of print brightly enough to read > "normally." And I specifically > want a white LED (or LEDs), for battery life - that's another problem > with an incandescent > flashlight, even with fresh alkalines, notwithstanding that stupid > spot - I need more of > a flood, so I don't have to keep pointing the light at the passage I'm > reading. > > I've heard tell of LED bike headlights and the like; what I want is > some wide-angle > "flood" light, that could illuminate an ordinary 8 1/2 x 11 page from > about two feet > (2/3M) away, while I'm at a normal reading distance (18-24" (1/2 - > 2/3M)), brightly > enough that I don't get eyestrain. > > Does anyone have any recommendations, or need more info? <http://www.harborfreight.com/cpi/ctaf/displayitem.taf?itemnumber=45807> <http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=93549> -- Greed is the root of all eBay.
From: Michael A. Terrell on 11 Feb 2010 21:31
Artemus wrote: > > These were on sale in the local HF store for 3.99 last week. Mine > works well although it is aimed too high when on my head. I haven't > used it long enough to tell how long the batteries last. > http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93549 > Art Then you should have bought this model: <http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=45807> -- Greed is the root of all eBay. |