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Groups > alt.folklore.computers > #150681
| Subject | Re: optimum power supply for subway/light rail lines |
|---|---|
| Newsgroups | alt.folklore.computers, nyc.transit |
| References | <5932e6a1-4930-466c-8bb8-4baadf9e9e77@googlegroups.com> <mriia7$435$1@dont-email.me> <aae3cc73-00f8-4ddf-944b-b154a3b2ee7f@googlegroups.com> <mrikig$bd3$1@reader1.panix.com> |
| From | "Joseph D. Korman" <joekor@earthlink.net> |
| Date | 2015-08-28 14:34 -0400 |
| Message-ID | <IPCdnR9AgJI3NH3InZ2dnUU7-ROdnZ2d@earthlink.com> (permalink) |
Cross-posted to 2 groups.
On 8/25/2015 4:52 PM, danny burstein wrote:
> In <aae3cc73-00f8-4ddf-944b-b154a3b2ee7f@googlegroups.com> hancock4@bbs.cpcn.com writes:
>
>> Somewhere I heard (unconfirmed) that subway train lamps had a relay to peri
>> odically switch polarity of the DC supply to the lamps back and forth. FWI
>> W, in the transit museum, some of the cars on exhibit remain still for long
>> periods of time, and one of their interior fl. lights is dark. Could that
>> have something to do with the polarity not being switched?
>
> Eyup. Back in roughly 1980 I had this really great booklet from
> Westinghouse which described their lighting products. (Alas it's
> gone to that great dustbin of history).
>
> They had a section about powering fluorescents via DC and mentioned
> the one-side darkening... and the importance of periodically
> flipping the current flow direction.
>
> The simple solution they recommended? Having a switch that
> reversed the polarity each time it was turned on.
>
> That stuck in my brane... and sometime later I was on
> one of the retrofitted subway cars which had been
> upgraded to fluorescent. And eyup, one of the tubes
> on the destination signs was dark on one side.
>
> We went over a switch which, at the time of the
> subway system design and that type of car.. gave
> us a couple of seconds of power outage (the battery
> powered emergency lights came on).
>
> When power was restored, the tube was fine...
>
> Speaking of which, anyone know if the trains still use lead
> acid storage batteries?
>
>
I'm not sure about the battery type, the data sheets list them as SAFT,
which may just mean Safety Electrical Co.
The cars from R-10 to R-40 were delivered with 20 minute timers to
reverse the polarity on the lighting. From the R-42 and all of the
overhauled the motor-generator set was replaced by solid state
conversion/voltage change equipment.
--
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| Visit The JoeKorNer at |
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|-------------------------------------------------|
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| may be a train going the other way! |
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optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-24 11:00 -0700
Re: optimum power supply for subway/light rail lines "hqhy" <hqhy@nospam.com> - 2015-08-25 04:47 +1000
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-24 15:01 -0500
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-24 14:45 -0500
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-24 13:22 -0700
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 13:26 -0500
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-25 11:48 -0700
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 16:12 -0500
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-25 20:20 -0700
Re: optimum power supply for subway/light rail lines danny burstein <dannyb@panix.com> - 2015-08-25 20:28 +0000
Re: optimum power supply for subway/light rail lines Morten Reistad <first@last.name.invalid> - 2015-08-24 21:42 +0200
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-24 15:14 -0500
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-25 08:07 -0700
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 12:52 -0500
Re: optimum power supply for subway/light rail lines scott@slp53.sl.home (Scott Lurndal) - 2015-08-25 20:06 +0000
Re: optimum power supply for subway/light rail lines Jon Elson <elson@pico-systems.com> - 2015-08-24 23:33 -0500
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 01:39 -0500
Re: optimum power supply for subway/light rail lines Morten Reistad <first@last.name.invalid> - 2015-08-25 10:23 +0200
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 12:30 -0500
Re: optimum power supply for subway/light rail lines Morten Reistad <first@last.name.invalid> - 2015-08-25 22:48 +0200
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-26 10:44 -0500
Re: optimum power supply for subway/light rail lines Morten Reistad <first@last.name.invalid> - 2015-08-26 18:03 +0200
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-26 12:04 -0700
Re: optimum power supply for subway/light rail lines Jon Elson <jmelson@wustl.edu> - 2015-08-25 14:15 -0500
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 15:15 -0500
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-25 13:33 -0700
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 15:49 -0500
Re: optimum power supply for subway/light rail lines danny burstein <dannyb@panix.com> - 2015-08-25 21:00 +0000
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 16:37 -0500
Re: optimum power supply for subway/light rail lines lawrence@cluon.com - 2015-08-25 23:52 +0200
fluorescents, was: optimum power supply for subway/light rail lines danny burstein <dannyb@panix.com> - 2015-08-25 22:25 +0000
Re: fluorescents, was: optimum power supply for subway/light rail lines lawrence@cluon.com - 2015-08-26 04:13 +0200
Re: fluorescents, was: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-25 20:24 -0700
Re: optimum power supply for subway/light rail lines JimP <solosam90@gmail.com> - 2015-08-25 19:11 -0500
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-25 20:36 -0700
Re: optimum power supply for subway/light rail lines Michael Black <et472@ncf.ca> - 2015-08-26 02:29 -0400
Re: optimum power supply for subway/light rail lines JimP <solosam90@gmail.com> - 2015-08-26 09:35 -0500
Re: optimum power supply for subway/light rail lines danny burstein <dannyb@panix.com> - 2015-08-25 20:52 +0000
Re: optimum power supply for subway/light rail lines "Joseph D. Korman" <joekor@earthlink.net> - 2015-08-28 14:34 -0400
Re: optimum power supply for subway/light rail lines Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-08-26 04:03 +0000
Re: optimum power supply for subway/light rail lines danny burstein <dannyb@panix.com> - 2015-08-25 20:36 +0000
Re: optimum power supply for subway/light rail lines hancock4@bbs.cpcn.com - 2015-08-25 08:10 -0700
Re: optimum power supply for subway/light rail lines Stephen Sprunk <stephen@sprunk.org> - 2015-08-25 12:18 -0500
Re: optimum power supply for subway/light rail lines danny burstein <dannyb@panix.com> - 2015-08-25 17:30 +0000
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