Home · Maps · About
Home > SubChat
 

[ Read Responses | Post a New Response | Return to the Index ]
[ First in Thread | Next in Thread ]

 

view flat

Re: What is the mechanical condition of the Low V?

Posted by Jeff H. on Fri Aug 8 02:51:08 2008, in response to Re: What is the mechanical condition of the Low V?, posted by MainR3664 on Thu Aug 7 23:34:29 2008.

edf40wrjww2msgDetail:detailStr
fiogf49gjkf0d
"Street Railway" bulbs, designed to be operated in series strings
of 5 from a 600VDC line, have two specific design characteristics:

1) The envelope is not filled with an inert gas, but is pure vacuum.

2) The filament support has a "Jacbob's Ladder" shape which tends
to stretch out the arc when the filament fails.

When the filament of an ordinary household bulb fails, either because
of mechanical shock or age, the arc which results has the full force
of 600 volts behind it, 5 times more than the 120 volts seen in
household service. It is DC, meaning the arc is not self-commuting.
The result is often that the arc fails to extinguish, and instead
ionizes the inert gas, briefly turning the bulb into an arc light
until the heat produced by it produces enough pressure to cause
the envelope to shatter. Or, the arc flashes down into the screw
base and then into the socket, destroying the socket and wiring and
often igniting whatever is nearby.

Responses

Post a New Response

Your Handle:

Your Password:

E-Mail Address:

Subject:

Message:



Before posting.. think twice!


[ Return to the Message Index ]