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Servo Question — Parallax Forums

Servo Question

kenwtnkenwtn Posts: 250
edited 2008-09-03 03:17 in General Discussion
Hi All,

···· I have several servos that over the years I have kept around even though the gears were shot. My question is when opened there is a small circuit board inside along with a motor and a Pot, is the circuit board like a H-Bridge? Also, I notice on the DC motor there are 3 wires +, - and ? the question is connected to the side of the motor what is that for?
·· My reason for asking is I would like to control another small DC motor I have.


Ken

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When you spend 10 times what it cost to build it yourself - That's when it becomes a HOBBY !

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Post Edited (kenwtn) : 9/1/2008 2:16:15 PM GMT

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-09-01 23:31
    Hello this question does not seem to be BASIC Stamp related and this post is being moved to the Sandbox Forum.

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    Chris Savage
    Parallax Engineering
  • kenwtnkenwtn Posts: 250
    edited 2008-09-02 01:03
    I sure would like to know what Chris's problem is? In the past he has deleted my posts, moved them and even remarked on how I stated my question. I could go to the BASIC forum now and find several Post that are not Basic Stamp related and find posts that the question is not well stated, but I seem to be the only one Chris has it in for. I have spent hundreds of dollars buying from Parallax but he seems to think in some way I do not deserve help. FIND I WILL END POSTING TO THIS FORUM just wanted others to be aware of Chris and his practice.

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    When you spend 10 times what it cost to build it yourself - That's when it becomes a HOBBY !

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  • Mike GreenMike Green Posts: 23,101
    edited 2008-09-02 01:51
    Hmmm. I've seen very similar feelings expressed before. I've been participating in this forum for a few years and have not seen any sense of unfair moderation on the part of Chris or Beau or other forum moderators. If anything, they seem to be busy sometimes for days letting conversations and requests and comments percolate before chiming in. There's a nice thread in the Support Forum (http://forums.parallax.com/showthread.php?p=725270) on this subject, going over some of the factors that make people's requests and questions more interesting for what is a nearly all volunteer "expert" audience.

    In any event, there are rules here and the opinions of the moderators in implementing them are final and that's the way things are.

    I saw your original message as I do most new messages. I didn't reply because I don't have any specific information to give. I think I opened up a servo once and it was to do something unrelated to the motor. I barely got it working again and I have little interest in doing that again. Maybe those who have more skill than I in such things just are not particularly interested in your question. Sorry. That happens sometimes.
    They're under no obligation to help you. It's nothing personal. Maybe some other question interests them more and they have limited time.
  • FranklinFranklin Posts: 4,747
    edited 2008-09-02 02:34
    Kenwtn, can you tell me what part of your original post had to do with the Basic Stamp? Chris does a fine job here and only moves,deletes,comments on those posts that don't follow the rules. Yes, some get through as it is not Chris's main job to police the forum, he does it when he has time. Sorry to see you go.

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    - Stephen
  • The Truth Is Out ThereThe Truth Is Out There Posts: 6
    edited 2008-09-02 02:37
    i want to thank you ken. you have inspired me to create an account today. so far i was happy to just read the messages posted and not get into things. i don't always agree with what is posted and i do fine just keeping that to myself. but lately i noticed something. since i did not have an account before today i only read messages from one page per day and i have noticed that chris has posted a lot of moves and deletion notices lately. reading your post i now see why. you went off on him for moving and deleting posts but you never stopped to look at why. it seems every post that was moved was off topic. it seems every message mentioning a deletion was because they were cross posted or duplicate. did you ever stop to think that if you followed the forum rules you wouldn't be making an *** out of yourself here now? sorry moderators but i can't keep watching people blame someone else for their own mistakes.

    hey you know what else i noticed? it is a holiday and chris is on here working cleaning the forums up and answering questions on what appears to be his day off. give him a freakin' break will ya?
  • John BondJohn Bond Posts: 369
    edited 2008-09-02 10:39
    You know Ken, I must be the most uncivilised person posting on this site ever. I am out of Africa you see so I probably know no better. I have always been treated exceptionally well.

    - I once threatened to kill poor Chan, another forum member. He sometimes still helps me.
    - I told poor Terry to hurry up with his new software. He still responds.
    - I have often sparred with Kramer and Jon
    - Like this post, I often get off the topic

    Lets face it, managing a forum and providing support is a thankless job. The people on this forum are truly OUTSTANDING!!!

    To the forum administrators – Thanks for moving, deleting and amending some of our misplaced posts. We appreciate it.

    To the volunteers who answer our sometimes dumb questions – We appreciate you effort, particularly because it broadens our knowledge.

    From the Dark Continent
    John Bond

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    Post Edited (John Bond) : 9/2/2008 10:44:25 AM GMT
  • Paul BakerPaul Baker Posts: 6,351
    edited 2008-09-02 18:54
    Hi Ken, as general policy we redirect questions that are better fit in another forum. We do this not to admonish members but to get thier question in the best place to have it answered. We are by no means perfect in this effort, but it shouldn't mean we should give up trying. Our conduct is clear and explicit, and is fully outlined in the forum guidelines: http://forums.parallax.com/showthread.php?p=467912. We·invoke guideline #7 whenever guideline #2 or #5 is not followed by the poster.·Your post does not discuss how to interface·a servo to a Basic Stamp, but on how to modify a servo, therefore was off topic for posting to the Basic Stamp forum. We are not trying to prevent your question from being answered but trying to get your question a better audience. By posting in the Basic·Stamp forum you were unneccesarily narrowing you audience to fellow Stamp users and not opening it up to SX and Propeller users who, with the exception of Mike Green,·rarely look in the Basic Stamp forum.·If you have been offended by our moving your post we appologize, but your assumption of our motive is incorrect.

    Now to your question at hand,

    Servos do use h-bridge type driver circuitry, but there is extra stuff used to provide the control layer.·The servo control loop uses the potentiometer to provide position feedback, this feedback is mixed with the control pulse (which indicates the target angle) to produce an error signal (target angle - current angle), the sign of this error indicates which direction the servo needs to turn and the magnitude indicates how fast it should move in that direction. If you are interested in what's actually going on with the signals, you should hook up an oscilloscope to the traces to get a better understanding of how the system works.

    Best Regards,·

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    Paul Baker
    Propeller Applications Engineer

    Parallax, Inc.

    Post Edited (Paul Baker (Parallax)) : 9/2/2008 7:49:36 PM GMT
  • kenwtnkenwtn Posts: 250
    edited 2008-09-02 22:13
    ·· After reading some of the comments made to my post I could not keep from replying. It would seem that some only read what they wanted in my post and attributed my comments to the fact my post had been moved. If you would have read what I wrote then you would have realized as a couple did that this is just the straw that pushed me over the top. When I first started using the Forum I once sent Chris a private message asking him a question and the reply I got was very rude went something like: “DO NOT USE PRIVATE MESSAGE TO CONTACT ME IF YOU HAVE A QUESTION THEN POST IT TO THE FORUM. FURTHER ABUSE WILL RESULT IN BEING KICKED OFF THE FORUM “ Since I was new to the forum I would have thought he could have been somewhat more polite about it and simple told me he would rather not be contacted by private message and not threaten me right off. Then there was the time I had a post going and it had run 2 – 3 days with many replies. Out of the blue I get a Email saying my post had be deleted by Chris. Then another post I made Chris replied and saying “When you make post to the forum your question should be phased to indicated what your post is about” Dang if I know where he came up with that one, others make post all the time like NEWBIE QUESTION Oh yeah like that explains what the post is going to be about. ·There have been many other things but I really do not wish to go on and on. Anyways I just thought those that reply should understand before doing so.
    ·· I have gotten alot of good help from the forum Mike has been very helpful in the past as well as Franklin and many others. I just had the feeling Chris has it in for me for whatever reason.

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    When you spend 10 times what it cost to build it yourself - That's when it becomes a HOBBY !

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  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-09-03 03:17
    Ken,

    I had hoped comments from other users would help you some but it is clear after this post that regardless of how much we try to help you, you are not going to follow the forum guidelines. In over three years of assisting members of these forums I have never once called a Private Message, abuse. I am sorry we could not help you.· Take care.

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    Chris Savage
    Parallax Engineering
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