[EVDL List]

Heat (to burn up your motor) comes from amps.

Power (to move your car) comes from watts.

Watts is the product of Amps times Volts.

Lets say that your car needs 10800 watts (10.8KW) to cruise at 55MPH.

You have a choice of;

36V times 300 Amps, which is right at the limit of youre motor's rating for amps.

or

72V times 150 Amps, which is half of the motor's rating and will allow it to run much cooler.


I agree.... go with the Alltrax 7245 or 7265 and shoot for a 72V system.


--
Stay Charged!
Hump
I-5, Blossvale NY
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Phelps
> Sent: Monday, July 30, 2007 1:57 PM
> To: [email protected]
> Subject: Type to use?
>
> Well this is all new to me.. So I don't know if I will keep the voltage
> the
> Same .. I don't need a lot of power.. But on the other hand I don't want
> to
> Wait 3 min to get to 55..
> I guess as far as increasing the voltage I am a bit uneasy with it..
> Because
>
> Of the stamp on the motor reads 30 volts.. Now I know I was told that ..
> The
>
> Stamp voltage is only one voltage that will work.. But if I raise the
> Voltage and double it would not the motor burn up if I cruised the high
> way
> For 40 mins?
> Or is that what you meant by forced air blower? A blower to cool the
> motor..
>
> Also Barkley stated.that he powered the
> Field of my aircraft generator with a separate 24volts... What's this
> about
> ? Is that just for his take off power?
> Or is that something that should be done. Will I loose out if I don't..
> Or
> Just be slower on take off?
>
> Mitchell
>
> Subject: Re: What type controller..
>
> Any controller you desire. Are you planning to keep it
> To 36 volt or go higher eventually?
> I have the JH-29 starter/generator and it is rate 48
> Volt 450 amps. Evolks drove them up to 96 volts but
> Maintained the 450 amps by using a Curtis. They also
> Ran it with 72 volt using an Alltrax AXE 7245. The AXE
> Series controller are programmable and usually
> Available from local Golf cart shops Hover they used
> Forced air blowers to run up the voltage. Hope this
> Helps

> --- Phelps <[email protected]> wrote:
>
>> Ok.. It is time for me to look at buying a
>> controller..
>>
>> Like I have stated before I have a Motor that takes
>> 30 volts at 300 amps,,
>>
>> However I am planing on using 36 volts and I guess
>> at times that would bring
>> the current up to 360 amps .
>>
>> It is a air craft starter engine. My car will weight
>> no more than 1500
>> pounds when done and that's with the batteries and
>> all..
>>
>> What are my choices for controllers that would do a
>> good job for this??
>>
>> I am also assuming that 36 volts will be ok when I
>> use a controller?
>>
>>
>> Thanks Mitchell
>>
>>
--
Stay Charged!
Hump
I-5, Blossvale NY

 

[EVDL List]

Ok .. But I was also told that when you increase the volts .. Amps will
increase also.. In a series motor.
Making the volts go to 72 would then make the amps go to over 600.. What is
it that I am not understanding?
So are you telling me that . I can control the amps?

Mitchell

-------Original Message-------

From: Tim Humphrey
Date: 07/30/07 14:22:25
To: EV
Subject: Re: Type to use?

Heat (to burn up your motor) comes from amps.

Power (to move your car) comes from watts.

Watts is the product of Amps times Volts.

Lets say that your car needs 10800 watts (10.8KW) to cruise at 55MPH.

You have a choice of;

36V times 300 Amps, which is right at the limit of youre motor's rating for
amps.

Or

72V times 150 Amps, which is half of the motor's rating and will allow it to
run much cooler.


I agree.... Go with the Alltrax 7245 or 7265 and shoot for a 72V system.


--
Stay Charged!
Hump
I-5, Blossvale NY
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Phelps
> Sent: Monday, July 30, 2007 1:57 PM
> To: [email protected]
> Subject: Type to use?
>
> Well this is all new to me.. So I don't know if I will keep the voltage
> the
> Same .. I don't need a lot of power.. But on the other hand I don't want
> to
> Wait 3 min to get to 55..
> I guess as far as increasing the voltage I am a bit uneasy with it..
> Because
>
> Of the stamp on the motor reads 30 volts.. Now I know I was told that ..
> The
>
> Stamp voltage is only one voltage that will work.. But if I raise the
> Voltage and double it would not the motor burn up if I cruised the high
> way
> For 40 mins?
> Or is that what you meant by forced air blower? A blower to cool the
> motor..
>
> Also Barkley stated.that he powered the
> Field of my aircraft generator with a separate 24volts... What's this
> about
> ? Is that just for his take off power?
> Or is that something that should be done. Will I loose out if I don't..
> Or
> Just be slower on take off?
>
> Mitchell
>
> Subject: Re: What type controller..
>
> Any controller you desire. Are you planning to keep it
> To 36 volt or go higher eventually?
> I have the JH-29 starter/generator and it is rate 48
> Volt 450 amps. Evolks drove them up to 96 volts but
> Maintained the 450 amps by using a Curtis. They also
> Ran it with 72 volt using an Alltrax AXE 7245. The AXE
> Series controller are programmable and usually
> Available from local Golf cart shops Hover they used
> Forced air blowers to run up the voltage. Hope this
> Helps

> --- Phelps <[email protected]> wrote:
>
>> Ok.. It is time for me to look at buying a
>> controller..
>>
>> Like I have stated before I have a Motor that takes
>> 30 volts at 300 amps,,
>>
>> However I am planing on using 36 volts and I guess
>> at times that would bring
>> the current up to 360 amps .
>>
>> It is a air craft starter engine. My car will weight
>> no more than 1500
>> pounds when done and that's with the batteries and
>> all..
>>
>> What are my choices for controllers that would do a
>> good job for this??
>>
>> I am also assuming that 36 volts will be ok when I
>> use a controller?
>>
>>
>> Thanks Mitchell
>>
>>
--
Stay Charged!
Hump
I-5, Blossvale NY

 

[EVDL List]

Phelps wrote:
> Ok... But I was also told that when you increase the volts, amps will
> increase also (In a series motor).

At a fixed rpm, raising the voltage will raise the rpm of a series
motor. But...

a) Your aircraft generator is not a series motor. It is a shunt motor.
In a shunt motor, the current is determined by the load placed on it.

b) The controller will limit the motor current, regardless of what the
motor tries to do.

> Making the volts go to 72 would then make the amps go to over 600.

No; raising the voltage to 72v means the motor rpm will be twice as much
for a given field current.

The current the motor draws will depend on the load, and the
controller's current limit setting (whichever is lower).

I used one of these aircraft generators in my first EV, at 72v. It
worked perfectly fine. It didn't overspeed, and it didn't draw too much
current.

--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

 

[EVDL List]

The reason I power my FIELD wiring separately from the
ARMATURE, is so that I have enough torque to start the
car from a deadstop at an incline. When I powered the
field and the armature all through the controller, the
field was being pulsed just as the armature was, and
my controller was going into current overload and
shuting down. It worked ok from flat terrain, but you
give it just a little slope or a rock in the road, and
it would not move. So when it was suggested I power
the field with a separate power pack, and just use the
controller to operate the armature with, it worked out
great. All I needed on the FIELD is 24vdc, and now
can shoot a 72+ power pack through the controller for
the armature of the motor. This setup is working out
great on my car, which is a pretty big vehicle for an
aircraft generator to push. I'm using an inline air
blower to force cool air into the motor for cooling
purposes also, maintaining around 170F at it's highest
temp, with the ambient outside air temp being 98F or
slightly higher at times.

You can limit your current in the programming of the
ALLTRAX controllers also.

--- Phelps <[email protected]> wrote:

> Ok .. But I was also told that when you increase the
> volts .. Amps will
> increase also.. In a series motor.
> Making the volts go to 72 would then make the amps
> go to over 600.. What is
> it that I am not understanding?
> So are you telling me that . I can control the amps?
>
> Mitchell
>
> -------Original Message-------
>
> From: Tim Humphrey
> Date: 07/30/07 14:22:25
> To: EV
> Subject: Re: Type to use?
>
> Heat (to burn up your motor) comes from amps.
>
> Power (to move your car) comes from watts.
>
> Watts is the product of Amps times Volts.
>
> Lets say that your car needs 10800 watts (10.8KW) to
> cruise at 55MPH.
>
> You have a choice of;
>
> 36V times 300 Amps, which is right at the limit of
> youre motor's rating for
> amps.
>
> Or
>
> 72V times 150 Amps, which is half of the motor's
> rating and will allow it to
> run much cooler.
>
>
> I agree.... Go with the Alltrax 7245 or 7265 and
> shoot for a 72V system.
>
>
> --
> Stay Charged!
> Hump
> I-5, Blossvale NY
> >
> > -----Original Message-----
> > From: [email protected]
> [mailto:[email protected]] On
> > Behalf Of Phelps
> > Sent: Monday, July 30, 2007 1:57 PM
> > To: [email protected]
> > Subject: Type to use?
> >
> > Well this is all new to me.. So I don't know if I
> will keep the voltage
> > the
> > Same .. I don't need a lot of power.. But on the
> other hand I don't want
> > to
> > Wait 3 min to get to 55..
> > I guess as far as increasing the voltage I am a
> bit uneasy with it..
> > Because
> >
> > Of the stamp on the motor reads 30 volts.. Now I
> know I was told that ..
> > The
> >
> > Stamp voltage is only one voltage that will work..
> But if I raise the
> > Voltage and double it would not the motor burn up
> if I cruised the high
> > way
> > For 40 mins?
> > Or is that what you meant by forced air blower? A
> blower to cool the
> > motor..
> >
> > Also Barkley stated.that he powered the
> > Field of my aircraft generator with a separate
> 24volts... What's this
> > about
> > ? Is that just for his take off power?
> > Or is that something that should be done. Will I
> loose out if I don't..
> > Or
> > Just be slower on take off?
> >
> > Mitchell
> >
> > Subject: Re: What type controller..
> >
> > Any controller you desire. Are you planning to
> keep it
> > To 36 volt or go higher eventually?
> > I have the JH-29 starter/generator and it is rate
> 48
> > Volt 450 amps. Evolks drove them up to 96 volts
> but
> > Maintained the 450 amps by using a Curtis. They
> also
> > Ran it with 72 volt using an Alltrax AXE 7245. The
> AXE
> > Series controller are programmable and usually
> > Available from local Golf cart shops Hover they
> used
> > Forced air blowers to run up the voltage. Hope
> this
> > Helps
> >

--- Phelps <[email protected]> wrote:
> >
> >> Ok.. It is time for me to look at buying a
> >> controller..
> >>
> >> Like I have stated before I have a Motor that
> takes
> >> 30 volts at 300 amps,,
> >>
> >> However I am planing on using 36 volts and I
> guess
> >> at times that would bring
> >> the current up to 360 amps .
> >>
> >> It is a air craft starter engine. My car will
> weight
> >> no more than 1500
> >> pounds when done and that's with the batteries
> and
> >> all..
> >>
> >> What are my choices for controllers that would do
> a
> >> good job for this??
> >>
> >> I am also assuming that 36 volts will be ok when
> I
> >> use a controller?
> >>
> >>
> >> Thanks Mitchell
> >>
> >>
> --
> Stay Charged!
> Hump
> I-5, Blossvale NY
>
>
>
>