[VAC] Re: Crimp Connectors

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

Allow me to show a specific example. For clearance lamps, type 1891 is
common. 2 mscp, 14 volts 240 milliamps, life 500 hours. 1893, 2 mscp,14
volts 330 milliamps, 7500 hours, same base and envelope. 1815, 1.4 mscp,
14 volts 200 ma, 3000 hours, same base and envelope. 1816, 3 mscp, 13
volts, 330 ma, 1000 hours, same package. 1895, 14 volts 270 ma, 2000
hours, same base, round glass. 57, 14 volts 240 ma, 500 hours, same
shape as 1895. So by using the 1893 instead of the several functional
equivalents, one has a chance of achieving up to 15 times the lamp life
at the cost of more energy when the lamps are lit. The longer lived lamp
has a fatter filament, hence a bit sturdier, and runs that filament at a
lower temperature hence the lower energy efficiency but far longer life.

MSCP is Mean Spherical Candle Power, the total light output from the
lamp.

In the past ten or 15 years, some makers of automotive lamps have added
tungsten oxide particles to the tungsten ingots so that the harder
tungsten oxide particles can act as keys between tungsten crystals to
strengthen the filaments further. Some claim that improvement is so
significant that one can't depend on a lamp braking or stretching in a
collision to prove the lamp was on while doing accident reconstruction.
Other reconstructionists are totally oblivious to facts.

Lamp mountings in modern vehicles often includes some rubber or soft
plastic to help isolate the lamps from shock and vibration. I've run a
truck 100,000 miles with only a single lamp failure. There's no need to
have to replace trailer lamps monthly or even annually.

Gerald J.