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propeller and servo's — Parallax Forums

propeller and servo's

Brian_BBrian_B Posts: 842
edited 2007-04-11 12:45 in Propeller 1
how big of resistors should I be using between the propeller proto board and servo's And/or a HB25.

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Thank's Brian


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Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2007-04-10 16:45
    Theoretically, you don't need any resistor there. Accidents do happen and component failures too. Any value from about 220 ohms to about 10K ohms would work. Any power rating from 1/10W up.
  • Brian_BBrian_B Posts: 842
    edited 2007-04-10 16:49
    I didn't think I needed one , but I've fried 2 proto boards . Is it possible for the HB25 to be spiking the board ?

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    Thank's Brian


    www.truckwiz.com

    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    http://www.diycalculator.com/subroutines.shtml· My favorite website ( Bet you can't guess why)
  • Mike GreenMike Green Posts: 23,101
    edited 2007-04-10 17:11
    Brian,
    The HB25 shouldn't be able to "spike" its input. There could be spikes on the ground connections or induced through the wiring harnesses by running high power wires alongside logic connections. QuattroRS4 has discussed an application using a Stamp to control a 15hp motor with all the electrical noise and spikes involved ... with no problems (eventually) from power surges (see: http://forums.parallax.com/showthread.php?p=642788). For what it's worth, the HB25 driver in the Object Exchange suggests a 1K resistor.
    Mike
  • QuattroRS4QuattroRS4 Posts: 916
    edited 2007-04-11 02:45
    Brian,
    When you say 'fried' - in what way? - did you loose all functionality or some ?

    Regards,
    Quattro

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    'Necessity is the mother of invention'

    Post Edited (QuattroRS4) : 4/11/2007 2:50:25 AM GMT
  • Brian_BBrian_B Posts: 842
    edited 2007-04-11 03:16
    I'm scratching my head , I don't know how to explain it. They worked fine at first , then they quit ,now one of them started working again .Arggg


    ps. this is on super_bot not the dragon wagon

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    Thank's Brian


    www.truckwiz.com

    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    http://www.diycalculator.com/subroutines.shtml· My favorite website ( Bet you can't guess why)


    Post Edited (Brian Beckius) : 4/11/2007 3:21:43 AM GMT
  • QuattroRS4QuattroRS4 Posts: 916
    edited 2007-04-11 03:42
    Brian,
    Don't know about any Bots - ? How are you powering the HB25 - what PSU/Battery ?
    How are you supplying the Demo board ?

    Sorry for asking loads of questions - just want to get the bigger picture here..

    Regards,
    Quattro

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    'Necessity is the mother of invention'
  • Brian_BBrian_B Posts: 842
    edited 2007-04-11 12:06
    Quattro,
    I'm using a small 12 volt battery to power the HB25's and the proto board (paul said 12 volt would be ok) I found that when the battery get's down to 12 volts thats when I start having issues , so I switched batteries and it worked fine smile.gif

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    Thank's Brian


    www.truckwiz.com

    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    http://www.diycalculator.com/subroutines.shtml· My favorite website ( Bet you can't guess why)
  • QuattroRS4QuattroRS4 Posts: 916
    edited 2007-04-11 12:18
    Thats good so Brian ...

    Quattro

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    'Necessity is the mother of invention'
  • Brian_BBrian_B Posts: 842
    edited 2007-04-11 12:45
    I know this sounds like a boneheaded mistake ( and it was) . But I checked the voltage and it wasn't clicking that 12 volt is dead . I didn't think about again until I checked a new battery that had 13.5 volts.

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    Thank's Brian


    www.truckwiz.com

    ·"Imagination is more important than knowledge..." ·· Albert Einstein

    http://www.diycalculator.com/subroutines.shtml· My favorite website ( Bet you can't guess why)
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