T-Pain Is On A Boat: Re: [Electric Boats] Controller using torque vs. speed

Wednesday, April 29, 2015

Re: [Electric Boats] Controller using torque vs. speed

Controlling speed is by controlling the voltage to the motor.

Controlling torque is by controlling the current to the motor.

With no load the voltage controller will go up to a certain speed.

But with no load the current/torque controller will keep speeding up
to whatever the maximum RPM is at full voltage, slowly or quickly
depending on the control, except at very low settings where the
friction load takes all the [very little] power at some lower point
of RPM.

It's fine in the water because the load goes up with speed and so
there's an equilibrium speed for a given current. Just the continual
speeding up might not be what you expect if testing it dry.

Craig

=====

>Luke,
>
>This should make no difference with you at the helm. A controller that is set
>to control RPM will try to keep that RPM up no matter what power is required.
>One that only trys to keep a set torque will not try to keep the RPM up and
>will better control the power usage. Your speed may not stay consistent but
>the power usage should stay more consistent. Come to think of it you may like
>the results more.
>
>Kevin
>
>On Monday, April 27, 2015 10:59:14 AM you wrote:
>> Hello,
>>
>>
>> I'm working on changing to a new controller. After install I learned that
>> with this particular controller the throttle controls the amount of torque.
>> In my previous setup my throttle controlled speed (RPM). What difference
>> will this make when actually in the water? Will I be able to notice at all?
>> On the hard the motor just reved up to max at only about 20% throttle, no
>> load to push agains so it requires almost no power to get to full revs. I'm
>> afraid of what this will be like in the water.
>
>>
>> Thanks,
>> Luke
>> Tartan 27 #478 "On the Brink"
>
>