The voltage isn't lowered. The motor is driven by pulse width
modulation (PWM) which means that the full voltage is available for
a fraction of the time. The modulation frequency is typically in the
10's of kilohertz.
What are you doing here then? :-)
It doesn't have to be a _computer_. And it certainly wouldn't be
/"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia
\ / ASCII ribbon campaign | I'm a .signature virus!
Like NOI says. Instead of calling us uninformed, why not use the
knowledge in you head and give us some reasons. I see that someone
brought up pulse control of the motor. That is a fine idea, but it
sounds rather expensive and how do the electronics in such a unit fare
with changing ambient conditions? What else can you bring to the
68' RS Camaro
88' Formula Bird
Some are wise and some are otherwise
On or about Sat, 14 Feb 2004 11:31:52 -0500, Thund3rstruck_N0i
Excuse me but isn't it called a thermostat? I seem to recall that most
cars have had those for a few years now? The thermostat closes
blocking the flow when the temperature goes down (the only reason you
need to restrict flow) and opens when the temperature gets hot.
There is no need to maintain a constant load on the motor. The only
potential problem is windage in the pump causing the water to boil if
all flow is stopped but that isn't a problem because, if you recall,
we have a thermostat near the pump outlet that allows flow when the
water gets warm.
If you insist on controlling the motor then you use discharge
pressure. Maintain a constant pressure at the pump outlet by
decreasing voltage. If the motor starts to stall the pressure falls
and the voltage goes back up. Same thing happens if the thermostat
opens and the flow increases.
Now if you want a real problem, that electric motor is rather large
and draws a hefty current. Where is that coming from? Now you need a
BIG alternator. With a BIG belt or, better yet, gear drive. Because of
losses converting mechanical motion to electricity and electricity
back to mechanical motion, the electric pump is going to take more
power from the engine than the simple mechanical pumps we have now.
Now you need an automatic full throttle cut out just like we already
have on the A/C compressors. But do you just cut off the pump risking
overheating or do you cut off the alternator risking loss of all
electrical power when the battery can't handle the load?
P.S. As an engineer I've seen more nonsense in this thread than most.
Weight reduction can make a significant improvement in acceleration or
it may never be noticed. The improvement is in direct proportion to
the percentage of weight change. I have a 36HP motorcycle that weights
350 pounds with me aboard. It's FAST!!! Much faster than my Corvette.
Put a 100 pound passenger on the back and it seems like it has trouble
outrunning a Geo. But add 100 pounds to a Hummer and you would never
A lot of people will waste good money on the latest "electro-magnetic
vortex storm" gizmo that promises to add "up to 10hp" when they could
get a guaranteed 10hp equivalent by a simple weight reduction that
would also yield better handling. 10Hp in a 400Hp machine is the same
as a 2.5% change in weight. You do the math. By the way, a gallon of
gas weighs about 8 pounds.
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