What is the smallest voltmeter?
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From: default on 4 Feb 2007 10:53 On Sat, 3 Feb 2007 17:36:05 -0500, "Michael Kennedy" <Mikek400(a)remthis.comcast.net> wrote: >You should look into a 3W Luxeon LED headlight. > >I have a luxeon LED flashlight and it is much brigher than any other >flashlight that I own.. It runs on 4 AA batteries for approx 4 hours. > >- Mike I second that idea. Though I'd probably go with a Cree LED if using more than one - they don't sell "bin numbers" their LEDs either meet specification or they don't sell them. I put 56, 13,000 mcd, white LEDs in an auxiliary light on my motorcycle and it is very bright - easily enough for a bicycle under most conditions. In daylight it is more noticeable than the headlight low beam. Burns 3.4 watts and outshines the 50 watt low beam. Only cost $9 Beam angle on that is only +/- 10 degrees - so it won't replace the low beam at night I have four Cree red LEDs in the tail lamp and it is way overkill . . I should have used just two. At $8 each Beam angle on those is 120 degrees -- ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =----
From: Paul E. Schoen on 6 Feb 2007 10:56
"default" <default(a)defaulter.net> wrote in message news:8dvbs212o0ar41i21p591e5bb0gglinhqt(a)4ax.com... > On Sat, 3 Feb 2007 17:36:05 -0500, "Michael Kennedy" > <Mikek400(a)remthis.comcast.net> wrote: > >>You should look into a 3W Luxeon LED headlight. >> >>I have a luxeon LED flashlight and it is much brigher than any other >>flashlight that I own.. It runs on 4 AA batteries for approx 4 hours. >> >>- Mike > > I second that idea. Though I'd probably go with a Cree LED if using > more than one - they don't sell "bin numbers" their LEDs either meet > specification or they don't sell them. > > I put 56, 13,000 mcd, white LEDs in an auxiliary light on my > motorcycle and it is very bright - easily enough for a bicycle under > most conditions. In daylight it is more noticeable than the headlight > low beam. Burns 3.4 watts and outshines the 50 watt low beam. Only > cost $9 Beam angle on that is only +/- 10 degrees - so it won't > replace the low beam at night > > I have four Cree red LEDs in the tail lamp and it is way overkill . . > I should have used just two. At $8 each Beam angle on those is 120 > degrees > -- > Yes, LEDs are definitely more efficient. I have designed a current regulated driver for strings of Cree LEDs. My friend Tony (www.patcoinc.com) is making a diving flashlight that will have either 7 or 13 of the 3 Watt LEDs (which requires up to about 50 VDC). My circuit (using a PIC and a boost converter) produces 750 mA from 10-14 VDC, and it has a low power mode which drives the LEDs at only 100 mA, which is still plenty bright. The circuit board is only 1" x 2". It also senses low battery condition and then flashes the LEDs to conserve power and also provide a warning. I'll be getting boards made soon. All the parts are maybe $10, and you can reprogram the PIC if you want other features or different output currents. It has about 90% efficiency. Let me know if you would like one of the boards for your project or others. Paul www.pstech-inc.com |