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View Full Version : Galvanometer instead of Servo?



B.Glen
04-27-2008, 10:05 AM
Has anyone ever used a moving coil galvanometer (volt meter) instead of a servo? Would it work as a silent alternative? Any ideas about control issues?

lasernerd
05-10-2008, 01:35 PM
For what purpose?
each have there high points

Adrenalynn
05-10-2008, 01:43 PM
>> each have there high points

That's the point where you elaborate on your opinion, Laser'

lasernerd
05-10-2008, 02:16 PM
>> each have there high points

That's the point where you elaborate on your opinion, Laser'

in which application??

A galvo is a more precise movement
Where a servo has more power less precision
based on many factors

"just my opinion"



galvo's depend on optical sensors "closed loop"
for position detection

servo's use a mechanical means for postion detection
or optical counting


for meter movement obviously you dont need optical detection for scale,,

Adrenalynn
05-10-2008, 02:32 PM
So they could very well work as a "silent alternative" for lighter torque applications. I'm sure there are other options for detecting position outside of optical. A potentiometer comes to mind.

What control issues might the OP face?

lasernerd
05-10-2008, 02:41 PM
So they could very well work as a "silent alternative" for lighter torque applications. I'm sure there are other options for detecting position outside of optical. A potentiometer comes to mind.

What control issues might the OP face?

A pot is mechanical

Optical position can be impaired by dust, ext. light illumination

yes,for sure a galvo can be very quit at lower speeds

but at 40K points per second they can become squealer!

Adrenalynn
05-10-2008, 02:55 PM
Sealed optical positioning is immune to both forms of impairment you note, and would probably be worth exploring in that application.

Sure, pots are mechanical. They're also a "good ol' standby", and with the "right" D/A can be quite worthwhile in some applications.

I've heard meters squeal, but they're still not as loud as an HS-805.. ;)

lasernerd
05-10-2008, 03:19 PM
yep,
thats why they have there own dutys