1745Re: [rsa] BS2, Vantec RDFR21, DC Motor ?
- Jun 27, 2005Quoting D K <dktkd@...>:
> So if a ESC takes commands like a servo, does the ESC also control a DCThe Electronic Speed Controller is just that - a motor SPEED controller. You
> motor like a servo?
> More specifically will it control the DC motor output to a given position
> based on the PWM,
> just as a servo would be commmanded to a given position based on the PWM?
> Or would it need feedback from an encoder to determine position?
> How do i control the speed of the motors using the ESC if i am only sending
> Stop (1.5ms), CCW (1 ms) and CW (2ms) PWM commands?
> Thanks everyone for helping me with my newbie questions.
can vary the direction and speed of a motor by varying the pulse width of the
input (i.e. servo) signal. Therefore, 1ms would be full-speed in one
direction, and 2ms would be full-speed in the other direction. Anything in
between will translate to a lower speed, typically with 1.5ms being "off".
By the way, servos that have been modified for free rotation (i.e. to be used
to drive wheels) behave similarly, but don't require the added expense of an
ESC. But it's slower, since servos are geared down a lot. But if you're
looking to simply rotate something to a known position, I think a servo is the
simplest (and cheapest) way to go.
If you want to note wheel rotation on a free-wheeling motor or servo, you
would have to use some kind of encoder to determine rotational position. And
I'm sure there must be a discussion board somewhere devoted just to that
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