Matt,In terms of traffic lights, the LEDs use much less electricity, don't know an exact number, probably 1/10, which is considerable when you multiply it out over the number of lights in a city. Also, and perhaps more importantly, they last a really long time, so when you consider a $100,000 man lift truck with 4 people on it getting union wages going around a city replacing incandescent lights every 1,000 hours , versus LEDs at about 100,000 hours, it really starts being worth considering. Of course out here in Cali, we don't have any snow problems except in the mountains, so they are in use all over. I have noticed that they are considerably brighter that the bulbs they replaced, too. As for the use of LEDs in automotive applications, they are vibration proof, and they are in use in all new semi trucks, because incandescence are very susceptible to vibration, semis have a lot of bulbs, and are checked for lights out, and fined for burned out bulbs. In automotive use, the reason for the resistor is that in old style blinker relays, they use the amp draw of the bulb to heat a filament in the flasher unit that then breaks the circuit, cools off, remakes the circuit, etc. When you use a trailer, or add lights on any other way, the flasher unit stops working properly, as you have changed the amp draw. Most auto parts houses will sell you a mechanical relay with timer, or an electronic one that replaces the old type flasher relay, which would then run the LEDs just fine. I would say that in a car that has shaped, model specific light lenses, it may not be worth changing to LEDs, especially since power use in a car is not an issue. In an electric vehicle, the power draw of the bulbs is still probably insignificant, especially in a tractor that uses them infrequently. If your car has an electronic flasher relay, retrofitting LED bulbs might be worth the expense in terms of reliability and reduced hassle of replacement, and you can always retro fit a flasher unit, but bulbs and electronic flasher will add up to some money. In anything like a trailer or flatbed that can use generic shaped lights, I think they provide much better life, and therefore reliability: I used to have to replace at least one bulb on my flatbed trailer every time I used it, and I put in some LED lights and they are going strong years later.
That's my 50 cent worth. anton matt wrote:
At 11:28 AM 11/24/03 -0500, you wrote:Interesting about how the incandescent's heat had been useful! Itsounded like some automotive systems, maybe like blinkers, can't deal with the low current draw of the LED replacements.then what good is it to use lites that use less power and need to put something in the line to up the power to make it work? same thing with the trafic lights? is it realy better? Matthew P. Magda Jr. _______________________________________________ Elec-trak mailing list Elec-trak cosmos phy tufts edu https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak