Community
Search
Notices
RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

Controlling PCM servo with switch

Thread Tools
 
Search this Thread
 
Old 02-18-2007, 02:17 PM
  #1  
makterna
Junior Member
Thread Starter
 
Join Date: Feb 2007
Location: None, SWEDEN
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Default Controlling PCM servo with switch

Electronics question, regarding rc-servos:

I am aware of how PCM coding works, but if I have an application where I only need the two extreme positions of the servo. Can I just send 0V for one position and 12V for one position? Some manufacturers say no, that I need a frequency too, but I remember having tried this in practise, and found it to work.

If not, can anyone please show me of how to make a simple resistor-capacitor circuit to create the frequency needed to make the rc-servo work?

I also want to know if I can connect two 6V servos in line with eachother, to a 12V power source. The servos are going to be operated simultaneously.

I would also appreciate recommendations of servo manufacturers. I need a servo which is weather resistant but otherwise reasonably priced. It's for a commercial invention that I'm trying to develop.

If it matters, I'm located in Sweden.

Best regards,
Erik
Old 02-18-2007, 03:07 PM
  #2  
DKjens
My Feedback: (50)
 
DKjens's Avatar
 
Join Date: Feb 2002
Location: Pasadena, CA
Posts: 2,097
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Controlling PCM servo with switch

Erik,
If you haven't already been there, you may want to try to post your questions on www.rc-unionen.dk I can think of a few people on that site who I think can give you your answers, and it's local to you as well.
DKjens
Old 02-18-2007, 04:48 PM
  #3  
tkilwein
Senior Member
 
tkilwein's Avatar
 
Join Date: Mar 2002
Location: denver, CO
Posts: 546
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Controlling PCM servo with switch

The servo requires a pulse width of ~1, 1.5, 2ms to function. one end, center, other end.
you can not just apply a voltage to the input.
Old 02-18-2007, 05:09 PM
  #4  
rmh
Senior Member
 
rmh's Avatar
 
Join Date: Dec 2001
Location: , UT
Posts: 12,630
Likes: 0
Received 3 Likes on 3 Posts
Default RE: Controlling PCM servo with switch

What you are looking for is a POD pulse omission detector servo --
Futaba had one a few years ago - very good 180 degree. I think number was " 136 retract servo"
but not 12v - and required the std Futaba rf rate.
when tx was OFF-- the servo saw no pulse -went to one direction - Then when you turned TX ON ,-- if--it saw a short pulse. it held that position - then selecting other switch position -LONG PULSE-- it rotated to other extreme end (180 throw). Ithink the servo pot had two tracks -- find one and see if it helps you.
Old 02-19-2007, 09:38 AM
  #5  
JRexA
Senior Member
 
JRexA's Avatar
 
Join Date: Oct 2004
Location: Nuuk, GREENLAND
Posts: 1,363
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Controlling PCM servo with switch

here you can find some info about a Servo tester, that can generate the correct signal:

http://www.uoguelph.ca/~antoon/index.htm

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.