Re: (ET) Lift motor control

[Anton and Federica <krustyacres earthlink net>]

It's all about heat buildup. In electric cars, you can put quite high 
amperage through a motor for a short period of time, as long as it's not 
high enough to fry anything directly, you just have to avoid heating 
things up enough to break down the insulation in the windings. There's 
most likely more to it than that, but that's essentially it. A large 
motor for an electric car is one rated at say, 20 hp, but on 
acceleration, it will safely put out 3 or 4 times that (round numbers) 
for a short period of time, as will the controller. The controller is 
the same, but usually has a temperature sensor that simply cuts back 
power to protect itself when the temp gets too high.
If that motor is already a little under built, you might possibly fry 
the brushes with more amps, but it is mostly intermittent use, and could 
most likely stand a little more heat.
Any opinions on that specific motor anyone?
anton

Dave & Debbie Barden wrote:

> could you then run it at say 20 volts get a little more speed out of the 
> motor and not harm the motor?
>
> dave
>
>  
>
> > I think the idea would be to run the controller at no more than 1/2 
> > 'power'.
> > If it is a PWM controller then I would think running it at half throttle
> > would provide an average 18V to the motor. I'm getting out of my area of
> > knowledge here, though, so those better informed correct me if I'm wrong!
> >
> > If this idea is right then one could build a fixed controller that is 50%
> > duty cycle - would be fairly simple.
> >
> > SteveS
> > E20
> >
> > ----- Original Message ----- 
> > From: "Dave & Debbie Barden" <daveb seanet com>
> > To: <ralphgv centurytel net>; <>
> > Sent: Tuesday, February 03, 2004 12:58 AM
> > Subject: Re: (ET) Lift motor control
> >
> >
> >    
> >
> > > the lift motor is only 18v.  I think I've seen warnings about shortening
> > >      
> > its
> >    
> >
> > > life running it at higher voltage.  you might check the archives...
> > >
> > > dave
> > > seattle
> > >
> > >      
> > >
> > > > Hi
> > > > I was wondering if anyone has any thoughts on using this controller for
> > > > running the lift motor on 36 volts?  It is rated for 20 amps at 36 volts
> > > > and only $42.00 each.   Go to
> > > > http://www.warehousesensations.net/x360_parts and scroll down to item #
> > > > X360-220 (AKA) "The Brain".
> > > >
> > > > Ralph Vogan
> > > > ralphgv centurytel net
> > > >        
> > > ralphgv centurytel net
> > >
> > >
> > >
> > >
> > >
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