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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. Thanks for the congratulations! Regarding safety: there are 6 exit lights, which had to be re-lamped 3 - 4 times per year. So the new wiring saved 25 (years) x 6 (lights) x 3.5 (relampings per year) or 525 trips up and down the ladder. It also kept hands and fingers out of electrically hot fixtures 525 times. Those fixtures are required to be on 24x7 - the only way to turn them off is at the breaker. So it saved 525 flips of the breaker - or more likely, it saved 525 instances of fingers inside a fixture that was electrically hot, human nature being what it is. The need for re-painting has also been reduced (more ladder climbing), but I cannot quantify that. With the old wiring, the wall and ceiling above the exit signs used to get dirty a lot sooner than it does now. Now with the above facts in mind, which do you think is safer? |
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Putting the bulbs in series seems to qualify as an improvement.
Perhaps that would not hold up in court, but we all know the law is an ass. On Wed, 03 Sep 2003 03:37:43 GMT, Jeffrey D Angus wrote: wrote: [ snip ] Now with the above facts in mind, which do you think is safer? That's the same logic that dictates about how much money the school board can save by NOT installing fire sprinklers in a school building. Jeff |
that would be nice ,let the shcools burn down.
The way education is going its better to BBQ.... "Jeffrey D Angus" wrote in message .. . wrote: [ snip ] Now with the above facts in mind, which do you think is safer? That's the same logic that dictates about how much money the school board can save by NOT installing fire sprinklers in a school building. Jeff -- "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." Benjamin Franklin "A life lived in fear is a life half lived." Tara Morice as Fran, from the movie "Strictly Ballroom" |
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%. 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 |
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... 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. Best regards, Spehro Pefhany -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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. Thanks for the congratulations! Regarding safety: there are 6 exit lights, which had to be re-lamped 3 - 4 times per year. So the new wiring saved 25 (years) x 6 (lights) x 3.5 (relampings per year) or 525 trips up and down the ladder. It also kept hands and fingers out of electrically hot fixtures 525 times. Those fixtures are required to be on 24x7 - the only way to turn them off is at the breaker. So it saved 525 flips of the breaker - or more likely, it saved 525 instances of fingers inside a fixture that was electrically hot, human nature being what it is. The need for re-painting has also been reduced (more ladder climbing), but I cannot quantify that. With the old wiring, the wall and ceiling above the exit signs used to get dirty a lot sooner than it does now. Now with the above facts in mind, which do you think is safer? Neither. Nowadays they put the exit signs down low, because the rising smoke from the fire fills up the rooms and the exit signs can't be seen. :-( 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. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
In article ,
mentioned... wrote: [ snip ] Now with the above facts in mind, which do you think is safer? That's the same logic that dictates about how much money the school board can save by NOT installing fire sprinklers in a school building. Jeff I dunno about where you live, but I believe Calif. state law requires that sprinklers be installed, so the school board has no choice. And even if there was no law, the school board would have to submit the building or remodeling plans for approval to the state board of education, and that would be the end of it. If it didn't meet their approval, it would be sent back to the architect for additions or changes. The fire chief told us that the architect did something really stupid. They spec'd that sprinklers be installed in our computer room, which is protected by a 'halon' system. So if there's a fire, all the equipment gets water damaged. Stoopid. But the sprinklers are there, just in case.. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
In article ,
mentioned... Putting the bulbs in series seems to qualify as an improvement. Perhaps that would not hold up in court, but we all know the law is an ass. No, the law _is_ the law. How the idiot lawyers and judges interpret it is another matter. Not a subject for discussion here, tho. On Wed, 03 Sep 2003 03:37:43 GMT, Jeffrey D Angus wrote: wrote: [ snip ] Now with the above facts in mind, which do you think is safer? That's the same logic that dictates about how much money the school board can save by NOT installing fire sprinklers in a school building. Jeff -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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 |
On 3/9/03 20:27, in article ,
"Watt Sun Watson A.Name -" wrote: 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? Sounds like when I was going to Drexel - for 12 years! -- Robert Morein. Failed 50 year old loser student. Failed Temple University Ejected from Grad program after seven years Ejected from Drexel University after dissertation judged "bull**** nonsense" Sued Drexel and Lost Even took it to the Supreme Court, but they laughed at me! But I get even with studentsandthelaw.org my harassment site. My poor jew mother Jane Morein died with a broken heart, watching this poor twisted loser fail at everything I've ever done. Daddy Sylvan Morein, who studied hard and became a fair to middlin' dentist, is now stuck at home with his loser son; unwanted by life or any of the relatives. But I've discovered at last my calling: INTERNET WACKO! Man, am I a Loser! |
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 |
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 | +--------------------------------------------+ |
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 |
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 |
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. |
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 |
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. |
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. |
Sounds like a great class, where you have to block the door to keep the
students from leaving. What was the class and who sponsored it? A mandatory safety class perhaps? Roy Lewallen, W7EL Watson A.Name - Watt Sun wrote: 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? :-))) |
"Sven Franklyn Weil" wrote in message ... 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. I've got one of those (somewhere) with R. Crumb's "Keep on Truckin'" guy as the filament...bought in the 70's, still worked the last time I plugged (screwed) it in. jak 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. |
030902 1644 - 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. Also, they should be checked to see if they still work properly when the power goes out and the battery system takes over. |
indago wrote:
030902 1644 - 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. Also, they should be checked to see if they still work properly when the power goes out and the battery system takes over. The signs I am familiar with used a different set of bulbs for battery operation, so they could be bad and you wouldn't know, without a monthly test. -- Michael A. Terrell Central Florida |
Jeffrey D Angus wrote: wrote: [ snip ] Now with the above facts in mind, which do you think is safer? That's the same logic that dictates about how much money the school board can save by NOT installing fire sprinklers in a school building. Jeff There's always those who will snipe at posts. But geez, man, at least get the sniping right. What you quoted is a question. See, it even has a question mark at the end. If you want to attack the logic, then attack the part of the post that presents the logic used. I'll make it easy for you: the facts are that the bulbs were burning out 3 - 4 times a year. The logic applied was that 3 - 4 failures per year per light over the course of 25 years yielded the 525 "ladder trips". And, by the way, neither the question you quoted, nor the snipped material mentioned saving money or eliminating anything, other than the failures and consequent repairs. Nor does your post add anything to the discussion, which has to do with lamps. Sheesh - try to illustrate how reducing voltage to a lamp increases longevity and you get a bunch of uninformed bull****. F.Y.I. - the place has been inspected yearly by the fire officials and passed every time. |
On Wed, 3 Sep 2003 03:31:59 -0700, Watson A.Name - "Watt Sun"
wrote: 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. These were actually Metal Oxide NTC thermistors back then (not Metal Oxide Varistors), since silicon diodes were at that time just a curiosity in the "ELECTRICAL" world as opposed to the "ELECTROMICS" world. The problem with the Diode or the NTC solution, is that it does nothing to save the bulb from line transients. I have seen actual VARISTORS being used for current regulation as opposed to surge suppression (clipping), but only in old telephone sets. I'm not shure of the principle behind this since a MOV is not a temperature sensitive device, and am curious if anyone can explain. A ballast based voltage drop, has better potential in that regard when combined with a VARISTOR and fuse for surge suppression. So for an extra $50.00 you get to keep your bulb longer. Hmm. Stepan |
In article , clare @
snyder.on .ca mentioned... 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. No, these are much brighter than a pilot light. Much bigger, too, Since they're red, they put out the proper color light without filtering. But this whole neon lamp for exit sign thread is moot. The new ones I've seen use LEDs and run off a SLA gel cell battery. Today I was working in a hallway with an exit sign that was about a foot (.3 m) off the floor. During the recent remodeling someone had knocked the cover loose so I took the cover off. I found that the sandwich behind the cover was unusual. The front layer was a clear diffuser made of plastic, sort of like the glass they use in bathroom windows, with bumps on one side. Underneath the glass was a thick tray with grooves cut (or cast) into it in the shape of the letters EXIT. Each groove had a pale yellowish rod laying in it, a bit thicker than a pencil lead. My guess is that this is some kind of phosphorescent material that glows when light from flames from a fire are hitting it. There is _no_ power to the sign. This kind of exit sign seems to be standard on all newer built buildings. And positioning them close to the floor is standard procedure, because exit signs above the doors become useless as the smoke rises and fills the room. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
Stepan Novotill wrote:
On Wed, 3 Sep 2003 03:31:59 -0700, Watson A.Name - "Watt Sun" wrote: 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. These were actually Metal Oxide NTC thermistors back then (not Metal Oxide Varistors), since silicon diodes were at that time just a curiosity in the "ELECTRICAL" world as opposed to the "ELECTROMICS" world. I think you have that backwards. Back then, the radio and TV sets were still using 5U4 TOOBS for rectifiers, whereas the electrical world already had equipment with SCRs up to the size of hockey pucks that could handle up to 1200 amps (http://www.cehco.com/sda.htm), and 1N1184 series of 35 amp stud mount rectifiers were common in equipment (http://dkc3.digikey.com/PDF/T032/0547.pdf). And your average battery charger had diodes in it, it just so happened that the manufacturers were still stuck back in the "Stink Stack" days, still using selenium rectifiers. The problem with the Diode or the NTC solution, is that it does nothing to save the bulb from line transients. The NTC worked well because most bulb failures occurred during turn-on. [snip] Stepan |
On Thu, 04 Sep 2003 14:36:25 -0700, the renowned Lizard Blizzard
wrote: The NTC worked well because most bulb failures occurred during turn-on. But soft-starting does not extend bulb life significantly in most cases. Voltage reduction is what does the trick. 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 |
I think that furthermore, the few volts lost in the NTC aslo goes a
long way to extending bulb life, regardless. s On Thu, 04 Sep 2003 22:53:34 GMT, Spehro Pefhany wrote: On Thu, 04 Sep 2003 14:36:25 -0700, the renowned Lizard Blizzard wrote: The NTC worked well because most bulb failures occurred during turn-on. But soft-starting does not extend bulb life significantly in most cases. Voltage reduction is what does the trick. Best regards, Spehro Pefhany |
On Thu, 4 Sep 2003 03:50:04 -0700, Watson A.Name - "Watt Sun"
wrote: Underneath the glass was a thick tray with grooves cut (or cast) into it in the shape of the letters EXIT. Each groove had a pale yellowish rod laying in it, a bit thicker than a pencil lead. My guess is that this is some kind of phosphorescent material that glows when light from flames from a fire are hitting it. There is _no_ power to the sign. Could it have been a tritium source? I've seen them to be yellowish glass vessels. It would be hard to see it glow without cupping your hand over it i think. |
In article ,
mentioned... On Thu, 4 Sep 2003 03:50:04 -0700, Watson A.Name - "Watt Sun" wrote: Underneath the glass was a thick tray with grooves cut (or cast) into it in the shape of the letters EXIT. Each groove had a pale yellowish rod laying in it, a bit thicker than a pencil lead. My guess is that this is some kind of phosphorescent material that glows when light from flames from a fire are hitting it. There is _no_ power to the sign. Could it have been a tritium source? I've seen them to be yellowish glass vessels. It would be hard to see it glow without cupping your hand over it i think. That sounds like it might be what's in the rods. I didn't try to see if it glowed when I darkenwed the area. I know that the H bombs that were made during the cold war years are losing srength because the tritium in them is decaying, so tritium doesn't last all that many years. That blgd is about ten years old. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
10 or 12 year half-life on tritium
On Thu, 4 Sep 2003 23:07:09 -0700, Watson A.Name - "Watt Sun" wrote: In article , mentioned... On Thu, 4 Sep 2003 03:50:04 -0700, Watson A.Name - "Watt Sun" wrote: Underneath the glass was a thick tray with grooves cut (or cast) into it in the shape of the letters EXIT. Each groove had a pale yellowish rod laying in it, a bit thicker than a pencil lead. My guess is that this is some kind of phosphorescent material that glows when light from flames from a fire are hitting it. There is _no_ power to the sign. Could it have been a tritium source? I've seen them to be yellowish glass vessels. It would be hard to see it glow without cupping your hand over it i think. That sounds like it might be what's in the rods. I didn't try to see if it glowed when I darkenwed the area. I know that the H bombs that were made during the cold war years are losing srength because the tritium in them is decaying, so tritium doesn't last all that many years. That blgd is about ten years old. |
On Thu, 04 Sep 2003 14:36:25 -0700, Lizard Blizzard
wrote: I think you have that backwards. Back then, the radio and TV sets were still using 5U4 TOOBS for rectifiers, whereas the electrical world already had equipment with SCRs up to the size of hockey pucks that could handle up to 1200 amps (http://www.cehco.com/sda.htm), and 1N1184 series of 35 amp stud mount rectifiers were common in equipment That could be. I was just a young pup in the 60s, but I remember the diodes were the top-hat kind that didn't fit into lamp-saver sockets. I don't recall seeing anything other than variacs for lamp dimmers either. |
In article ,
mentioned... Sounds like a great class, where you have to block the door to keep the students from leaving. What was the class and who sponsored it? A mandatory safety class perhaps? It's a temporary setup for registration, not a class. We have a dozen or more PCs set up for students to register for classes. When they're done they go over to the next room to pay their fees. Understand, Rubber Band? Roy Lewallen, W7EL Watson A.Name - Watt Sun wrote: 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? :-))) -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
In article ,
mentioned... On Thu, 04 Sep 2003 14:36:25 -0700, Lizard Blizzard wrote: I think you have that backwards. Back then, the radio and TV sets were still using 5U4 TOOBS for rectifiers, whereas the electrical world already had equipment with SCRs up to the size of hockey pucks that could handle up to 1200 amps (http://www.cehco.com/sda.htm), and 1N1184 series of 35 amp stud mount rectifiers were common in equipment That could be. I was just a young pup in the 60s, but I remember the diodes were the top-hat kind that didn't fit into lamp-saver sockets. I don't recall seeing anything other than variacs for lamp dimmers either. When I was in the army in the late '60s we were constantly replacing those top hat rectifiers in the CRTs for the radars. In each lead, they had 3 or 4 1N547s, each rated 600V, 1/4A, in series, with a cap across each one, to rectify the B+. The deflection plates used pretty high B+ so the diodes were always failing. If we would have been smarter, we wwould have put more in series, but then Military Intelligence was an oxymoron. :-P They used to use fuse holders to hold the top hats and help keep them cool. Later they came out with a metal package that was a bit longer and smaller in diameter, with no 'hat brim', so it could fit into a button that would fit into the lamp socket. We should find out from one of the 'Semiconductor Antiquities Experts' when the 1N4002 series of epoxy case rectifiers caame out. My 1969 Motorola manual has them in it, and uses them as a substitute for the top hat rectifiers. The 1N4002 series must have been out in the mid '60s or maybe earlier. Someone recently mentioned Poly Paks. Those surplus sales companies used to sell grab bags full of those old top hat diodes, probably slightly leaky or lower voltage than usual. Same with the old TO-5 germanium transistors. Today those guitar FX nuts would drool over a bag of decent quality Ge transistors. :-P' ' ' -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
Stepan Novotill wrote:
10 or 12 year half-life on tritium Oh that's pretty good. That link earlier said "guaranteed for 6 months," they made it sound like it would be good for a year or so, was wondering why they were that expensive if they only lasted a year. :) |
030904 1736 - Lizard Blizzard wrote:
Back then, the radio and TV sets were still using 5U4 TOOBS for rectifiers, whereas the electrical world already had equipment with SCRs up to the size of hockey pucks that could handle up to 1200 amps Imagine the size of the heatsink for that... |
indago wrote:
030904 1736 - Lizard Blizzard wrote: Back then, the radio and TV sets were still using 5U4 TOOBS for rectifiers, whereas the electrical world already had equipment with SCRs up to the size of hockey pucks that could handle up to 1200 amps Imagine the size of the heatsink for that... The heatsink is "live" for that style rectifier. It has to be tightened onto the rectifier (sandwitched) using several bolts. There's acually a compression rating - if a certain static force is not present during operation, it will explode... :) |
In article ,
mentioned... 030904 1736 - Lizard Blizzard wrote: Back then, the radio and TV sets were still using 5U4 TOOBS for rectifiers, whereas the electrical world already had equipment with SCRs up to the size of hockey pucks that could handle up to 1200 amps Imagine the size of the heatsink for that... Things with big SCRs, like motor controllers, don't have a heatsink as you would think of it. They use a square tube with fins pointing into the cavity, and fans on the end. -- @@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@ h@e@r@e@@ ###Got a Question about ELECTRONICS? Check HERE First:### http://users.pandora.be/educypedia/e...s/databank.htm My email address is whitelisted. *All* email sent to it goes directly to the trash unless you add NOSPAM in the Subject: line with other stuff. alondra101 at hotmail.com Don't be ripped off by the big book dealers. Go to the URL that will give you a choice and save you money(up to half). http://www.everybookstore.com You'll be glad you did! Just when you thought you had all this figured out, the gov't changed it: http://physics.nist.gov/cuu/Units/binary.html @@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@ u@e@n@t@@ |
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