"art" wrote in message
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On 23 Jan, 14:49, "Jimmie D" wrote:
"art" wrote in
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snipurs did you have on this projector at failure? Part of
engineering a design is lifetime expectancy, judging by the projectors
I've seen over the past few years a three CRT projector has exceeded
it's expected lifetime.Doubt if it was a fault in engineering. If the
engineers had their way it
would probably be a dale heatsinked to the chassis.Often one engineering
team designs it and another goes through to find out how they can cut
corners.- Hide quoted text -- Show quoted text -

Jimmy it is rare to use two resisters instead of one because a board
becomes bigger
and introduces cost. When you get to power resisters it is not unusual
to place two
in parallel and accept the cost. In this case a cost improver would
try to make the case
for one single resister instead of four since a Dale with heatsink
would be
comparitively prohibative. The engineers calculation for wattage may
well have
been correct without being side blinded by the fact of some square
form resisters.
Art


Depends on the cost of the resistors. Prices seem to increase somewhat
expotentially with wattage so the two smaller ones may have been cheaper
than one larger. In this case the cost improver would have went for the
multiple resistors.