RE: (ET) motors

["Elie, Larry \(L.D.\)" <lelie ford com>]

You are right, but that is a SAFETY FEATURE.  Most cutting involves the 
inertia of the motor.  
It is turning 3,000 RPM.  If the resistance is brief, a fraction of a 
second, the change in 
speed is small.  If you hit something, you WANT IT TO STOP.

Larry Elie

-----Original Message-----
From: elec-trak-bounces cosmos phy tufts edu
[mailto:elec-trak-bounces cosmos phy tufts edu]On Behalf Of Chris Zach
Sent: Friday, June 11, 2004 7:37 PM
To: neil
Cc: elec-trak cosmos phy tufts edu
Subject: Re: (ET) motors


Running three in series simply will not work.

Reason is if one motor encounters some resistance, it will immediately 
stop and it's power will be transmitted to the two remaining motors. 
Remember that a motor under load will drop resistance. If you have 
another resistor in the circuit, it will just absorb more of the 
voltage. Same reason you can't just put a resistor in series with a 
motor and expect it to work.

This can be demonstrated on my daughter's Power Wheels car. In "slow" 
speed, the motors are in series, in fast they are in parallel. When in 
series, if one wheel starts to slip at all, it spins very fast as the 
other motor stalls. If one wheel bogs down under load, it gets 0% power.

Sorry.
Chris


neil wrote:

> Just wondering, how would a fan motor, like from a truck, work as a 
> mower motor, again putting 3 in series to handle the voltage.
> 
> wombat
> 
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