Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: ocservo on March 28, 2015, 03:30:34 AM

Title: Any suggestions for choosing servos
Post by: ocservo on March 28, 2015, 03:30:34 AM
I'm new here, and I want to build a robot, but after studied some reference, some of them have too many coils lead to pcb。 I want to know
if there are some servos that can be connected in series.
Thanks for advices
Title: Re: Any suggestions for choosing servos
Post by: mklrobo on March 28, 2015, 05:14:41 AM
 :D Hello!
In this forum, with the servos used for small robotics, I have not
seen any servos in series. By my understanding, they must be pulsed
to maintain their position, and more pulses to move. The serial capability
of that sceanario is doubtful. I am confident that there are serial servos,
but I have not seen any. You may be able to hook them up in parallel,
with pulses and power provided to the servo simultaneously. Good Luck!   ;D ;D ;D
Title: Re: Any suggestions for choosing servos
Post by: bdeuell on March 28, 2015, 01:19:59 PM
Typically it would be undesirable to connect servos in series and much more practical to wire them in parallel. However, I am sure there are special cases when it would be desirable to connect motors in series. A better explanation of what you are trying to achieve would help us provide the best recommendation for your application.

Please explain exactly what you are looking for when you say "servo". Technically a servo is just a motor with closed loop feedback. Below are a couple types of servos that may be what you're looking for.

Hobbyists are often most familiar with "RC servos" these typically have three wires (power, ground, and signal). For these servos the power and ground wires would be connected in parallel. The signal wire uses a pulse variable pulse length to control what position the servo should move to (there is lots of information about this on the web). if you are going to provide the same signal to several servos these could also be wired in parallel.

There are also Dynamixel servos which are specifically targeted at robotics (hobby level/not industrial). These servos have several wires (i'm not sure the exact pinout) and use a serial communication bus to transmit the control signal. This design allows the servos to be daisy chained (this is different from connecting the motors in series as they are still electrically connected in parallel). There may other brands that produce similar products but I have seen the Dynamixel ones before (never used them tho).





Title: Re: Any suggestions for choosing servos
Post by: ocservo on March 29, 2015, 07:35:19 PM
Typically it would be undesirable to connect servos in series and much more practical to wire them in parallel. However, I am sure there are special cases when it would be desirable to connect motors in series. A better explanation of what you are trying to achieve would help us provide the best recommendation for your application.

Please explain exactly what you are looking for when you say "servo". Technically a servo is just a motor with closed loop feedback. Below are a couple types of servos that may be what you're looking for.

Hobbyists are often most familiar with "RC servos" these typically have three wires (power, ground, and signal). For these servos the power and ground wires would be connected in parallel. The signal wire uses a pulse variable pulse length to control what position the servo should move to (there is lots of information about this on the web). if you are going to provide the same signal to several servos these could also be wired in parallel.

There are also Dynamixel servos which are specifically targeted at robotics (hobby level/not industrial). These servos have several wires (i'm not sure the exact pinout) and use a serial communication bus to transmit the control signal. This design allows the servos to be daisy chained (this is different from connecting the motors in series as they are still electrically connected in parallel). There may other brands that produce similar products but I have seen the Dynamixel ones before (never used them tho).
Anyway thanks u very much, but I will still make them connected in series in my way.
Title: Re: Any suggestions for choosing servos
Post by: mklrobo on March 31, 2015, 04:40:15 AM
 :) Hello!
When you do hook them up in series, please advise the
techniquie. I may be able to use the information in another
project. I appreciate your help. Thanks!   ;D ;D ;D
Title: Re: Any suggestions for choosing servos
Post by: ocservo on March 31, 2015, 11:53:13 PM
:) Hello!
When you do hook them up in series, please advise the
techniquie. I may be able to use the information in another
project. I appreciate your help. Thanks!   ;D ;D ;D

no problem ;)