Post by thread:[EE] R/C servos

Hi guys On the R/C servos when you stop at a certain position do you rely on the high torque generated by the gears to keep the motor braked or does the controller inside the servo actually breaks the motor electrically? If it is the later do you guys have any info on it that you could share. Best regards Luis

Luis, There is no brake on an R/C servo. The servo is designed so that its position is dependant upon the pulse width of the controlling input signal. If any external force is applied to the servo, the device will automatically try to correct the positional error. If you stop supplying the controlling input, the servo will go to sleep after a short period and will allow any external force to change its position. The gearing only makes it a little more difficult to move. Ken spam_OUTklumiaTakeThisOuTadelphia.net {Original Message removed}

At 01:31 AM 7/12/2005, Luis Moreira wrote: >Hi guys >On the R/C servos when you stop at a certain position do you rely on the >high torque generated by the gears to keep the motor braked or does the >controller inside the servo actually breaks the motor electrically? If it is >the later do you guys have any info on it that you could share. Best regards > Luis If you stop pulsing, then you're only held by friction. If you keep pulsing, then you are held electrically.

Hi Kenneth, My idea of how it works is the chip on the servo just translates the impulse time into travel and direction, then it waits for the feedback to equal the travel and when it gets there it breaks the servo. Then it waits for next pulse and repeats sequence, if no pulse supplied servo goes into idle... Do you think the servo is simpler? Am I looking to much into it? Regards Luis Luis Moreira .....luis.moreiraKILLspam@spam@jet.uk tel. 01235464615 JET PSU Department UKAEA Culham Division J20/1/55, Culham Science Centre Abingdon Oxfordshire OX14 3DB {Original Message removed}

> Hi Kenneth, > My idea of how it works is the chip on the servo just translates the > impulse time into travel and direction, Yes, an error pulse(difference between local and input pulse) is generated. > then it waits for the feedback to equal the travel The old Signetics chip(NE544) just sent out a streched error pulse that should move it to the correct postion. Ther was no checking if it got there until the next pulse. Not sure about modern servo ICs(MITSUBISHI M51660). > and when it gets there it breaks the servo. Don't think so except maybe for digital servos. > Then it waits for next pulse and repeats sequence, if no pulse supplied > servo goes into idle... Do you think the servo is simpler? Am I > looking to much into it? Mike DeMetz N9GEZ n9gezKILLspamqsl.net

part 0 44 bytes his is a multi-part message in MIME format. part 1 613 bytes content-type:text/plain; charset=us-ascii; format=flowed (decoded 7bit) The ones I worked with 10 years ago would receive a signal and move to a position. they had an internal pot for ref. if it moved and the signal was still there the motor would move it back. Luis Moreira wrote: {Quote hidden}>Hi guys >On the R/C servos when you stop at a certain position do you rely on the >high torque generated by the gears to keep the motor braked or does the >controller inside the servo actually breaks the motor electrically? If it is >the later do you guys have any info on it that you could share. Best regards > Luis > > > > part 2 391 bytes content-type:text/x-vcard; charset=utf-8; (decoded 7bit) begin:vcard fn:Robert I. Nelson n:Nelson;Robert I. org:RIN Designs adr:;;P.O. BOX 373;RIPON;WI;54971;USA email;internet:.....rindesignsKILLspam.....charter.net tel;work:1-(920)-229-7152 tel;home:1-(920)-748-7443 note;quoted-printable:Custom design and building of small electro mechanical devices.=0D=0A= AUTOCAD work ver2002 x-mozilla-html:FALSE version:2.1 end:vcard part 3 35 bytes content-type:text/plain; charset="us-ascii" (decoded 7bit)

Hi Dave, I am interested on what the chip inside the servo does, not on the pulse. The pulse is the command you give it but the chip inside translates that into angle and direction. Regards Luis Luis Moreira EraseMEluis.moreiraspam_OUTTakeThisOuTjet.uk tel. 01235464615 JET PSU Department UKAEA Culham Division J20/1/55, Culham Science Centre Abingdon Oxfordshire OX14 3DB {Original Message removed}