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#51
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On Wed, 3 Sep 2003 03:31:59 -0700, the renowned Watson A.Name - "Watt
Sun" wrote: In article , mentioned... On Wed, 03 Sep 2003 02:28:32 GMT, the renowned (Sven Franklyn Weil) wrote: You then screw this entire thing into the socket. It's called a "bulb saver" and is essentially a tiny diode in series that chops the voltage across the bulb in half. snip The RMS voltage across the bulb is reduced by ~29%. Ooh, DejaVu, I think we've had this discussion before... It's like the UL about pulsing LEDs to get more brightness, it just keeps coming around. The bulb savers that I used back in the '70s were varistors. They slowed down the turn-on of the light. They were low resistance when warm, and high when cold. There was no diode. I've seen the diodes, not the varistors. But I have no doubt you're right. Probably very similar to the inrush limiters used on PC power supplies, minus the leads. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
#53
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Watson A.Name - Watt Sun wrote:
Hey, I agree with you. But instead, I would have used higher voltage lamps, two in parallel. Decent LEDs were hard to get back in the '70s. Another solution might be to use neon lamps. You mean flourescent lights. neon lamps need a high voltage transformer. :-( you will not want them for emergency lights, as they are often the cause of the emergency themselves. BTW also fluorescent lights have many shortcomings, in a cold environment(Alaska?) they extinguish and won't start at even moderately cold temperatures. They need some electronics inside the socket and finally last not longer than special longlife bulbs, that is 6000h, which is not even 1 year. Of course the efficiency is much higher even if you add the loss of the electronics (which is usually not accounted for). Here in my building we have flourescent lights in the emergency lights, but they are always off and only light up at power loss. They have a 12Ah 12V gel-battery inside and will power the 5W lamp for not even 24h, not enough if we have a blackout like in NY. But fortunaterly that has never happened so far. ciao Ban Bordighera,Italy |
#54
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Watson A.Name - Watt Sun wrote: In article , mentioned... nobody wrote: In wrote: But in 1978 I wired the 2 bulbs in the each of the EXIT lights in the church in series. Congratulations, you probably bypassed a safety feature. If they're in parallel, if one burns out the other keeps going. In series, if one goes they're both out, and the exit sign is no longer visible. But if he'd have left them in parallel, they most certainly would have both burned out long ago! :-p Cheers, Fred I gotta tell you what happened at work last week. The head of security came over and told us that someone had complained that one of our tables was blocking the door (it's a temporary setup). The head of registration told him that she put it there to keep the students from leaving. The security guy says, but that's an emergency exit, see that sign up there? So she says, oh, ok. Well, then, can we move the sign? :-))) LOL! But hey, makes sense to me. "If Mohammed won't go the the mountain, the mountain will bloody well just have to come to Mohammed!" Cheers, Fred -- +--------------------------------------------+ | Music: http://www3.telus.net/dogstarmusic/ | | Projects: http://dogstar.dantimax.dk | +--------------------------------------------+ |
#55
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My limited experience with a group of exit lights is that they used
special expensive bulbs, but the electric supply place I went to find replacements suggested some relatively new (at the time) replacements which had a significantly long life spec. They were (are) neon bulbs as I remember, and they have lasted many years. Well worth the money. Exit fixtures have specs on what bulbs are to be used, I think. Also, as someone stated wrongly about neon bulbs requiring high voltage, they instead need series R to limit the current. --Phil nobody wrote: In wrote: But in 1978 I wired the 2 bulbs in the each of the EXIT lights in the church in series. Congratulations, you probably bypassed a safety feature. If they're in parallel, if one burns out the other keeps going. In series, if one goes they're both out, and the exit sign is no longer visible. -- Phil Munro Dept of Electrical & Computer Engin Youngstown State University Youngstown, Ohio 44555 |
#56
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Ban wrote:
Watson A.Name - Watt Sun wrote: Hey, I agree with you. But instead, I would have used higher voltage lamps, two in parallel. Decent LEDs were hard to get back in the '70s. Another solution might be to use neon lamps. You mean flourescent lights. neon lamps need a high voltage transformer. :-( Neon lamps need a current limiting resistor, something like 47k or so, but not a transformer. Some of the screw base neons have the resistor built into the base. Some of the ones I've seen have a standard sized 'edison' lamp base with a glass envelope that's about twice the size of the base. They last something like tens of thousands of hours. They would solve the problem of burned out filaments. you will not want them for emergency lights, as they are often the cause of the emergency themselves. BTW also fluorescent lights have many shortcomings, in a cold environment(Alaska?) they extinguish and won't start at even moderately cold temperatures. They need some electronics inside the socket and finally last not longer than special longlife bulbs, that is 6000h, which is not even 1 year. Of course the efficiency is much higher even if you add the loss of the electronics (which is usually not accounted for). Here in my building we have flourescent lights in the emergency lights, but they are always off and only light up at power loss. They have a 12Ah 12V gel-battery inside and will power the 5W lamp for not even 24h, not enough if we have a blackout like in NY. But fortunaterly that has never happened so far. ciao Ban Bordighera,Italy |
#57
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In article , Lizard Blizzard wrote:
Neon lamps need a current limiting resistor, something like 47k or so, but not a transformer. Some of the screw base neons have the resistor That's the case with the teenytiny neon night-lights that are commonly built into clock radios and things. They sell those at Radio Shack. Bought a two-pack there last year. The large neon tube signs need a ballast in order to kick start the tube...similar to fluorecent lights. -- Sven Weil New York City, U.S.A. |
#58
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Sven Franklyn Weil wrote: In article , Lizard Blizzard wrote: Neon lamps need a current limiting resistor, something like 47k or so, but not a transformer. Some of the screw base neons have the resistor That's the case with the teenytiny neon night-lights that are commonly built into clock radios and things. They sell those at Radio Shack. Bought a two-pack there last year. The large neon tube signs need a ballast in order to kick start the tube...similar to fluorecent lights. What is it? full moon? (no, that's a week away). I guess some young'uns just enjoy arguing what they don't know about... ;-) Look up the following: NE-30, NE-34, NE-40 and NE-56. At three watts on an edison base - the NE-40 is an impressive Neon bulb. (and yes it runs fine on 120VAC - in fact it'll fire at about 85V) best regards... -- randy guttery A Tender Tale - a page dedicated to those Ships and Crews so vital to the United States Silent Service: http://tendertale.com |
#59
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In article , Randy and/or Sherry wrote:
At three watts on an edison base - the NE-40 is an impressive Neon bulb. (and yes it runs fine on 120VAC - in fact it'll fire at about 85V) I keep forgetting about those decorative neon flicker bulbs - the ones with two closely positioned plates cut out in the shapes of crosses, stars of David, fish, women, flames, etc. Those are so delicate that one little tap can send one of those lamps into convulsions and possibly premature failure. I had a set of the flames in a menorah and every year there's one or two that just ... go out...maybe they're all too close together (about inch or two apart). Isn't there an issue with capacitance between those bulbs if they're close together that causes them to go nuts? -- Sven Weil New York City, U.S.A. |
#60
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On Wed, 03 Sep 2003 10:15:14 -0700, Lizard Blizzard
wrote: Ban wrote: Watson A.Name - Watt Sun wrote: Hey, I agree with you. But instead, I would have used higher voltage lamps, two in parallel. Decent LEDs were hard to get back in the '70s. Another solution might be to use neon lamps. You mean flourescent lights. neon lamps need a high voltage transformer. :-( Neon lamps need a current limiting resistor, something like 47k or so, but not a transformer. Some of the screw base neons have the resistor built into the base. Some of the ones I've seen have a standard sized 'edison' lamp base with a glass envelope that's about twice the size of the base. They last something like tens of thousands of hours. They would solve the problem of burned out filaments. The only problem is the (described) Neon lamp does not provide a high enough light output for emergency egress signs. They tend to be a very weak, flickering orange. Make a good pilot light, but not much more. |
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