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Simple Motor Control — Parallax Forums

Simple Motor Control

ArchiverArchiver Posts: 46,084
edited 2003-05-16 13:51 in General Discussion
What's a simple way to get my BS2 to control an 12v DC motor of
about 1.5A at stall? I would like to isolate the BS2 signal to
protect it. There's got to be a quick simple way to do this..

Chuck

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-05-01 14:48
    One direction or two. One direction can be done with a transistor. Two
    directions takes an H-Bridge arrangement.

    Original Message
    From: chuck_6730 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=71vHx5ZaCJHLGhUsA6aW2jvH28N8q71BoVCuL0CeMmF1PRSrZmqlU2_YIIprtlAi8E962ReqP5TZ1V-MEVxe]chuck_6730@y...[/url
    Sent: Thursday, May 01, 2003 9:08 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Simple Motor Control

    What's a simple way to get my BS2 to control an 12v DC motor of
    about 1.5A at stall? I would like to isolate the BS2 signal to
    protect it. There's got to be a quick simple way to do this..

    Chuck


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    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-05-01 14:57
    check out my web site for a solution
    http://www.geocities.com/jimforkin2003/

    Original Message
    From: Sadler Porter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=RKkQTQFXdD98NVfCjT3nYtVot5fWBaHE2MtDpMSFcQQ9e8HC3JD_hFq5yWwMxEg1oXeQDsGLQyam0rI_QrEZ]porter.sadler@s...[/url
    Sent: Thursday, May 01, 2003 9:49 AM
    To: basicstamps@yahoogroups.com
    Subject: RE: [noparse][[/noparse]basicstamps] Simple Motor Control


    One direction or two. One direction can be done with a transistor. Two
    directions takes an H-Bridge arrangement.

    Original Message
    From: chuck_6730 [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=qpOR3NLUw0cdLR49IsxjuEjZ3WzSrnO_kIiCgfITYwu-WtdN4YEGmzL2-J7jVAGQFt1Nb9j2XI_Dpdd2Ik3n]chuck_6730@y...[/url
    Sent: Thursday, May 01, 2003 9:08 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Simple Motor Control

    What's a simple way to get my BS2 to control an 12v DC motor of
    about 1.5A at stall? I would like to isolate the BS2 signal to
    protect it. There's got to be a quick simple way to do this..

    Chuck


    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
    from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.


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    [noparse][[/noparse]Non-text portions of this message have been removed]


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  • ArchiverArchiver Posts: 46,084
    edited 2003-05-16 04:26
    chuck_6730 wrote:
    > What's a simple way to get my BS2 to control
    > an 12v DC motor of about 1.5A at stall?

    ChuckSadler Porter wrote:
    > One direction or two[noparse][[/noparse]?]
    > One direction can be done with a transistor.
    > Two directions takes an H-Bridge arrangement.

    Actually, you can do both directions with
    only two transistors and a DPDT reversing relay
    (plus a kickback diode for the relay). <grin>
    One transistor is the current sink for the motor,
    and the other runs the motor reversing relay.

    The advantage is that you only need ONE high powered
    MOSFET (and heatsink) for running even a serious
    current motor. The relay just needs any old cheap
    NPN transistor that's just good enough to trip it.
    The relay CONTACTS need to take the motor current,
    which is easy.


    My question though: Do you only want on/off control,
    or proportional speed?

    With either an H-bridge design or the above circuit,
    to control your speed you'll need to use PULSOUT
    commands to modulate the MOSFET (or transistors).

    The problem with using PULSOUT comes in multimotor
    applications. Your program is stuck and ignoring
    the world while it is busy generating the PWM pulse
    for one motor. That's why you see so many EXTERNAL
    "multichannel motor controller" products out there
    for Stamps to use. They unload the BS2 from that task.

    chuck_6730 wrote:
    > I would like to isolate the BS2 signal to
    > protect it. There's got to be a quick simple
    > way to do this..

    Use an optoisolator between the BS2 outputs and
    the transistors. You can get quad optos in
    a single pack from Digikey to run an H-bridge.

    - Keith Mc.
    --
    "It's not an optical illusion... It just looks like one..."
  • ArchiverArchiver Posts: 46,084
    edited 2003-05-16 04:40
    Did this with a BS1 on a small RC car robot. Used a small DPDT relay driven
    with a 2n222 to switch directions and a TIP120 transistor to PWM the motor.

    Original Message

    > > What's a simple way to get my BS2 to control
    > > an 12v DC motor of about 1.5A at stall?
    >
    > ChuckSadler Porter wrote:
    > > One direction or two[noparse][[/noparse]?]
    > > One direction can be done with a transistor.
    > > Two directions takes an H-Bridge arrangement.
    >
    > Actually, you can do both directions with
    > only two transistors and a DPDT reversing relay
    > (plus a kickback diode for the relay). <grin>
    > One transistor is the current sink for the motor,
    > and the other runs the motor reversing relay.
    >
    > The advantage is that you only need ONE high powered
    > MOSFET (and heatsink) for running even a serious
    > current motor. The relay just needs any old cheap
    > NPN transistor that's just good enough to trip it.
    > The relay CONTACTS need to take the motor current,
    > which is easy.
    >
    >
    > My question though: Do you only want on/off control,
    > or proportional speed?
    >
    > With either an H-bridge design or the above circuit,
    > to control your speed you'll need to use PULSOUT
    > commands to modulate the MOSFET (or transistors).
    >
    > The problem with using PULSOUT comes in multimotor
    > applications. Your program is stuck and ignoring
    > the world while it is busy generating the PWM pulse
    > for one motor. That's why you see so many EXTERNAL
    > "multichannel motor controller" products out there
    > for Stamps to use. They unload the BS2 from that task.
    >
    > chuck_6730 wrote:
    > > I would like to isolate the BS2 signal to
    > > protect it. There's got to be a quick simple
    > > way to do this..
    >
    > Use an optoisolator between the BS2 outputs and
    > the transistors. You can get quad optos in
    > a single pack from Digikey to run an H-bridge.
  • ArchiverArchiver Posts: 46,084
    edited 2003-05-16 13:51
    check out this web site
    http://www.geocities.com/jimforkin2003/


    Original Message
    From: Keith Mc. [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=twNlSBo79-6Chl8FD6OwWnhCp4jG5LtTsZvr4HileJRqcQiq3wV1HbgL494DffXN3maWgFEdOxaQ]acti@P...[/url
    Sent: Thursday, May 15, 2003 11:27 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] RE: Simple Motor Control


    chuck_6730 wrote:
    > What's a simple way to get my BS2 to control
    > an 12v DC motor of about 1.5A at stall?

    ChuckSadler Porter wrote:
    > One direction or two[noparse][[/noparse]?]
    > One direction can be done with a transistor.
    > Two directions takes an H-Bridge arrangement.

    Actually, you can do both directions with
    only two transistors and a DPDT reversing relay
    (plus a kickback diode for the relay). <grin>
    One transistor is the current sink for the motor,
    and the other runs the motor reversing relay.

    The advantage is that you only need ONE high powered
    MOSFET (and heatsink) for running even a serious
    current motor. The relay just needs any old cheap
    NPN transistor that's just good enough to trip it.
    The relay CONTACTS need to take the motor current,
    which is easy.


    My question though: Do you only want on/off control,
    or proportional speed?

    With either an H-bridge design or the above circuit,
    to control your speed you'll need to use PULSOUT
    commands to modulate the MOSFET (or transistors).

    The problem with using PULSOUT comes in multimotor
    applications. Your program is stuck and ignoring
    the world while it is busy generating the PWM pulse
    for one motor. That's why you see so many EXTERNAL
    "multichannel motor controller" products out there
    for Stamps to use. They unload the BS2 from that task.

    chuck_6730 wrote:
    > I would like to isolate the BS2 signal to
    > protect it. There's got to be a quick simple
    > way to do this..

    Use an optoisolator between the BS2 outputs and
    the transistors. You can get quad optos in
    a single pack from Digikey to run an H-bridge.

    - Keith Mc.
    --
    "It's not an optical illusion... It just looks like one..."

    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
    from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.


    Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
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