|
[DPRG] Re: Motor stuff
Subject: [DPRG] Re: Motor stuff
From: Subhobroto Sinha
subhobroto at gmail.com
Date: Sun Apr 1 18:32:53 CDT 2007
On 3/27/07, Chuck McManis <cmcmanis at mcmanis.com> wrote:
>
> >>Ask yourself this question "What happens when the motor has an
> instantaneous
> >> load?"
>
> > The power supply sags momentarily ?
>
> > If so what are the solutions ? Optoisolation ?
>
> Often power supply sag can be an issue. There are several options, one is to
> put a resistor between the power supply and the motors, this will limit the
> current to the motors. Another is to put a diode/capacitor shunt between the
> power supply and the logic (the capacitor powers the circuit while the power
> supply sags, the diode prevents the capacitor from discharging back into the
> power supply.
There is a reason why I was away for over a week.
I (wrongly) suspected that my SMPS were not able to supply enough
regulation/power/power sag was taking place...
A scope across the microcontroller power terminals told the story...
The moment the motors started a lot of NOISE appeared in the power supply...
I already had the diode/capacitor shunt in place and expected this to
attenuate noise.. but that was not to be.
Finally, did a complete optoisolated board and now my bot's as merry
as I wanted :)
But I am not satisfied...
Is it not possible to use a LC/RC network (something like a snubber)
to attenuate the noise which is originating from the motors ?
Whoa ! Motors are wild beasts !
Cheers
Subhobroto Sinha
http://www.subhobroto.co.nr
>
> Separate power supplies for logic and motors is an easy an well tested way
> to solve the problem.
>
> --Chuck
>
>
More information about the DPRG mailing list
|
