servo control via lpt problems

Hi all
i am working on a small project in VB, Controlling Servos by voice.
everything is working great except for one thing.
If i use one power adapter to control more than 1 servo, then
following happens
While 1 servo moves , second servo seems to get enough of a voltage
fluctuation that it will move one way or the other.
so
currently for this to work for me, i need to have a separate power
supply for each servo, then
everything works great.
What do i need to make this work from one power supply?
TIA
Mike

 

Filter between the feeds to the two servos will also help, if its a PWM
servo then even with one power supply with enough current, the Power supply's
inherent output impedance may be too high for the servo's instantaneous
draw, you might need to size a supply that has a continuous rating that is
equal to the max instantaneous draw of *both* servos. If you are not sure than
add lots of capacitors and maybe separate leg inductors and capacitors
right next to the bridge driver for each servo...


--
Regards
Mike
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"Mitch

** Any decent, regulated, 5 volt PSU with a few amps capacity.

Not the puny unregulated ones you have.



........ Phil