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Power Supply for Parallax Servo Controller — Parallax Forums

Power Supply for Parallax Servo Controller

Scott HScott H Posts: 3
edited 2004-09-15 00:07 in BASIC Stamp
Does anyone have a recommended power supply for use with the Parallax Servo Controller?

Thanks for the help.

Scott

Comments

  • cabojoecabojoe Posts: 72
    edited 2004-09-10 05:43
    There is a hookup diagram in the manual: http://www.parallax.com/dl/docs/prod/motors/ServoController.pdf

    I would use the stamp's 5 volt supply to power the processor, and a 5 to 7.5 volt battery pack or wall wart to power the servo section. Parallax has a nice wall wart here: http://www.parallax.com/detail.asp?product_id=750-00009

    Not all servos can handle 7.5 volts, most will however. To make a simple 5 volt pack for the servos get a 4 AA battery holder and stick four AA batteries in it. Example: http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F001%5F000&product%5Fid=270%2D387
  • John BJohn B Posts: 82
    edited 2004-09-10 15:57
    Hi Scott H,

    ·· The selection of the servo power supply for the Parallax Servo Controller must be based on the type of servos used,·how they·will be·used, and if powered by batteries, how long you need them to operate on a single charge.· The variety of servos available today made us hesitant to recommend any one supply or battery configuration.·

    ·· I prefer batteries to power the servos as they add no [noparse][[/noparse]electrical] noise and, if sized properly, can supply oodles of current when needed.· Here are some guidelines that can help you decide·how to proceed.

    1)· Determine the required voltage of the servo(s) you will be using.· The safe bet for hobby-type servos is 5VDC.· Some servos will tolerate up to 7.5VDC, but some·get twitchy if too much voltage is applied.

    2)· Determine amount of current per hour that your servos will consume.· To make this measurement accurate for your system, you can measure the average current consumed while the servo is being used in a manner similar to how it will be used in the final system.

    3)· Find the total number of milliAmp-Hours (mA-hr) required by multiplying the mA measured by the total number of servos and the length of time you wish to have your battery last (adding 10% to this number is a good idea).

    4)· Construct or buy a battery or supply that has these same voltage and current attributes.· Remember: batteries in parallel add mA-Hrs while batteries in series add their voltages.

    ·· I hope this helps you.· If you require more help, feel free to email me directly, or give·our Tech Support guys a call.



    John Barrowman

    Engineering

    Parallax, Inc.

    jbarrowman@parallax.com

    www.parallax.com
  • Scott HScott H Posts: 3
    edited 2004-09-15 00:07
    cabojoe and JohnB,

    Many thanks to you both for your suggestions, which were both timely and useful!

    Since I have not yet picked the final number of servos in my work-in-progress, I am going to begin with the 4 AA battery holder then re-evaluate in a bit. If I get bogged down, I will definitely drop you an email John wink.gif

    Once again, thanks!!

    Scott
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