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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 |
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 |
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. |
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. |
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