richard@gryphon.COM (Richard Sexton) (12/15/89)
After spending the last month researching various lighting systems for my fishtanks, I have to ask: Whay are car headlights still crude tungstan filament (appx. 20 lumens per watt) whenthey could be metal halide (> 100 lumens per watt)? Certainly the power to tunt is more or less ``free'', but could not a lot more light be shed on the road from a good set of metal halide headlamps ?
mjb%hoosier.utah.edu@cs.utah.edu (Mark Bradakis) (12/15/89)
In article <23418@gryphon.COM> richard@gryphon.COM (Richard Sexton) writes: >Whay are car headlights still crude tungstan filament (appx. 20 >lumens per watt) whenthey could be metal halide (> 100 lumens >per watt)? The simple answer is that vehicle lighting is covered by federal regulations. It is getting better, though, but still... mjb. mjb@hoosier.utah.edu "If I took a rollin' wheel, rolled it ten times 'round..."
mmm@cup.portal.com (Mark Robert Thorson) (12/16/89)
There's a company (Cibie, I think) which makes a bulb holder for small halogen bulbs. The bulb holder is the same size and shape as a normal headlight. When installed in your car, they look just like normal headlights. On low beam, they are about as powerful as ordinary headlights, but on high beam they put out a lot more light. BTW, they are illegal for on-road OR OFF-ROAD use in CA. But you can buy them at local auto accessories shops. (You gotta install them yourself.)
ari@Ahwahnee.stanford.edu (Ari Ollikainen) (12/17/89)
In article <25070@cup.portal.com> mmm@cup.portal.com (Mark Robert Thorson) writes: >There's a company (Cibie, I think) which makes a bulb holder for small >halogen bulbs. The bulb holder is the same size and shape as a normal >headlight. When installed in your car, they look just like normal >headlights. On low beam, they are about as powerful as ordinary headlights, >but on high beam they put out a lot more light. > >BTW, they are illegal for on-road OR OFF-ROAD use in CA. But you can >buy them at local auto accessories shops. (You gotta install them yourself.) CIBIE also makes the BOBI "sealed" halogen lamps with removable/replaceable bulbs which ARE DOT legal in all the states including California. These have a modified Euro pattern.
peg@psuecl.bitnet (PAUL E. GANTER) (12/17/89)
In article <25070@cup.portal.com>, mmm@cup.portal.com (Mark Robert Thorson) writes: > headlights. On low beam, they are about as powerful as ordinary headlights, > but on high beam they put out a lot more light. > > BTW, they are illegal for on-road OR OFF-ROAD use in CA. But you can > buy them at local auto accessories shops. (You gotta install them yourself.) Perhaps there is a good reason for them to be illegal? You might not care if you are blinding oncoming drivers, but if they run into you head on it might ruin your day. Maybe you should wait until cross-polarized windshields and headlamps are available on all cars before you go replacing your primary headlamps. I personally find "normal" halogen lamps, when properly aimed, very effective--and I'm driving nasty Pennsylvania mountain roads with deer all over the place (a few less deer as of this week!!). Paul
roy@phri.nyu.edu (Roy Smith) (12/17/89)
In article <72824@psuecl.bitnet> peg@psuecl.bitnet (PAUL E. GANTER) writes: > Maybe you should wait until cross-polarized windshields and headlamps > are available on all cars before you go replacing your primary headlamps. I've been hearing about this for years. Or is that decades? I seem to remember talking about it in the early 70s. Is it every going to happen? Judging from the $90 extra it cost me to get polarizing filters in my sunglasses, I would guess whole polarized windshields will not be cheap. -- Roy Smith, Public Health Research Institute 455 First Avenue, New York, NY 10016 roy@alanine.phri.nyu.edu -OR- {att,philabs,cmcl2,rutgers,hombre}!phri!roy "My karma ran over my dogma"
strong@tc.fluke.COM (Norm Strong) (12/20/89)
In article <23418@gryphon.COM> richard@gryphon.COM (Richard Sexton) writes: }After spending the last month researching various lighting }systems for my fishtanks, I have to ask: } }Whay are car headlights still crude tungstan filament (appx. 20 }lumens per watt) whenthey could be metal halide (> 100 lumens }per watt)? } }Certainly the power to tunt is more or less ``free'', but }could not a lot more light be shed on the road from a good }set of metal halide headlamps ? As a matter of fact, the electricity used in your car is the most expensive electricity you'll ever use. It's generated by a small, inefficent generator operated by a gasoline engine, which is also inefficient. Now the heater is another matter; it DOES operate for free. -- Norm (strong@tc.fluke.com)
geopi@cbnewsh.ATT.COM (george.p.cotsonas) (12/22/89)
In article <23418@gryphon.COM>, richard@gryphon.COM (Richard Sexton) writes: > I have to ask: > Whay are car headlights still crude tungstan filament (appx. 20 > lumens per watt) whenthey could be metal halide (> 100 lumens > per watt)? I read an article recently about a HID (high intensity discharge) lamp coming out of (I think) GE, which should become available in some cars in the early 90s, and more generally available in the late 90s with complete headlamp assemblies slimming down to a mere 1" diameter. The active part is only about 5/16" wide and an inch or two long. So, those crude tungsten filaments may well become a thing of the past... -- George P. Cotsonas George.P.Cotsonas@att.ATT.COM AT&T Bell Laboratories or geopi@hocpa.att.com Holmdel, New Joisey or att!hocpa!geopi