To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.robotics.handyboardOpen lugnet.robotics.handyboard in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 Robotics / Handy Board / 1306
1305  |  1307
Subject: 
RE: dual servo update
Newsgroups: 
lugnet.robotics.handyboard
Date: 
Tue, 21 Jan 1997 17:12:11 GMT
Original-From: 
Chuck McManis <cmcmanis@SPAMCAKEfreegate.net>
Viewed: 
1299 times
  
Two things to note in the servo investigation:


Wiring a 1000microf electrolytic across the 6V within inches of each
servo seems to work.

This supplies a reserve of current to the servos, and that allows them to
seek to their desired position faster.

However, a much more important fix has been disconnecting the
servos from the wall jack and running them off of a 6V battery pack instead.
I was using a high quality regulated DC power supply, but nonetheless
it seemed to be making trouble.

Two servos, when moving, can pull two AMPS of current. Thats 2000mA. Two
large servos can pull four AMPS.  Very few 'wall bug' type supplies can provide
this level of power (if they do, they are usually of the pregnant snake variety,
you know, a cord that plugs into the wall, a big brick in the line, and then a cord
that plugs into the appliance)

all that I can say is  that the shorter and less complicated
the routine, the beter the servos behave.

Servos also must get a pulse at *LEAST* every 20mS. So perhaps there are
times where you miss one now or then. Since they can take pulses more
often than that perhaps Fred or someone can reduce the cycle time to compensate
for  times when the processor is too busy to get back to them in time?

--Chuck



Message has 1 Reply:
  RE: dual servo update
 
(...) I send my servos commands every 32.768 mS, and they work fine. I don't know what the limit is, but I don't think that 20 mS (50 Hz) is critical. * Michael L. Ross/C33 | Lockheed Martin Eng & Sci Svcs Co. **** * Robotics Department | 2400 Nasa (...) (28 years ago, 22-Jan-97, to lugnet.robotics.handyboard)

2 Messages in This Thread:

Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

Custom Search

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR