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Variable Resistor — Parallax Forums

Variable Resistor

ArchiverArchiver Posts: 46,084
edited 2001-02-23 02:12 in General Discussion
I am looking for a way to replace the variable resistor in a
wheelchair control joystick. there are two pots in the joystick,
each controlling the motors with a pulse-modulation type circuit. I
need a way to imitate the variable resistors with no physical
connections between the wheelchair circuits and the stamp circuits.

My thought was to use 4 cds cells and small lamps and use the pwm
output of the stamp to vary the brilliance of the lamps. I haven't
tried this yet, but does anyone have another (better) way?

TIA

Doug Simpson

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-02-22 13:27
    On Thu, 22 Feb 2001, Doug Simpson wrote:

    > My thought was to use 4 cds cells and small lamps and use the pwm
    > output of the stamp to vary the brilliance of the lamps. I haven't
    > tried this yet, but does anyone have another (better) way?

    What about the PWM output going to an optoisolator?
    Are you wanting to separate the two circuts to prevent motor noise
    from entering the BS circut?

    Mike
  • ArchiverArchiver Posts: 46,084
    edited 2001-02-22 15:52
    You could try 4 linear hall effect sensors. Their output voltage depends on
    the closeness (and strenght) of a magnet which could be mounted on the
    control handle.

    Good Luck,
    Jim

    > I am looking for a way to replace the variable resistor in a
    > wheelchair control joystick. there are two pots in the joystick,
    > each controlling the motors with a pulse-modulation type circuit. I
    > need a way to imitate the variable resistors with no physical
    > connections between the wheelchair circuits and the stamp circuits.
    >
    > My thought was to use 4 cds cells and small lamps and use the pwm
    > output of the stamp to vary the brilliance of the lamps. I haven't
    > tried this yet, but does anyone have another (better) way?
    >
    > TIA
    >
    > Doug Simpson
    >
    >
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-02-23 01:43
    [font=arial,helvetica]if you do try the optoisolators check out CP Clare.
    LCA-110's
    LCB-110's
    available from Digi-Key

    good luck[/font]
  • ArchiverArchiver Posts: 46,084
    edited 2001-02-23 02:12
    You may want to take a look at http://www.melexis.com/· they probably have something that would work.· They also make the hall effect sensors that I had suggested before.· They also make other sensors too.· Check it out.

    Jim Szymczak
    Original Message
    From: moretraction@aol.com
    To: basicstamps@yahoogroups.com
    Sent: Thursday, February 22, 2001 8:43 PM
    Subject: Re: [noparse][[/noparse]basicstamps] Variable Resistor

    [font=arial,helvetica]if you do try the optoisolators check out CP Clare.
    LCA-110's
    LCB-110's
    available from Digi-Key

    good luck
    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

    [/font]
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