.
>> You can put two (similar) light bulbs in series, and they will split the
>> voltage evenly. If, however, you put two motors in series, even if
>perfectly
>> matched in terms of current draw and general condition, one will
>invariably
>> start before the other, and what is known as a "chase" condition will
>occur.
>> One pump will run very fast, possibly to the point of burning out, and the
>> other will just sit there and pass current to the other.
That depends on what kind of motor it is. Permanent magnet motors connected
in series actually work pretty well, I have a pair of fans for which low
speed is series and high is parrallel, they do not hunt or chase or stall.
Shunt wound motors can work in series but best if you seperate the fields
and armatures and wire each in series seperately. Series wound motors, as I
recall, would have the most trouble running in series with another motor.
So the question is, what kind of motors are in those fuel pumps, not knowing
I would guess PM's.
But since you have a battery center tap the question is moot anyway.
Connect each motor to each battery, there is no imbalance in current draw
and both motors will get correct and constant voltage, but of course you'd
need a two pole switch to turn them on and off.
But then, why not just buy a 24V pump?
that is all,
je
This archive was generated by hypermail 2b29 : Tue Aug 07 2001 - 09:34:12 PDT