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h bridge control — Parallax Forums

h bridge control

ArchiverArchiver Posts: 46,084
edited 2000-06-27 16:55 in General Discussion
Can anyone suggest a simple h bridge design?

Can the job be accomplished with 4 transistors and some protection diodes??
I don't have much experience with transitors and am worried about having to
find the right resistor values to bias them.
Also, where should any caps go to minimize trans. voltages???

I only want to control 2 dc motor gearboxes.. I believe they are rated at 3
volts and about 0.9 amps.

Thanks
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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2000-06-27 04:50
    Check the Nuts and Volts archives. They had some good H-bridge writeups, (I
    believe in the April & May 2000 issues.)

    Also, someone on this list suggested http://www.cadvision.com/blanchas. It
    had some informative discussions using Mosfets for H-bridges.

    Good luck,
    Ray McArthur

    > Can anyone suggest a simple h bridge design?
    >
    > Can the job be accomplished with 4 transistors and some protection
    diodes??
    > I don't have much experience with transitors and am worried about having
    to
    > find the right resistor values to bias them.
    > Also, where should any caps go to minimize trans. voltages???
    >
    > I only want to control 2 dc motor gearboxes.. I believe they are rated at
    3
    > volts and about 0.9 amps.
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-27 13:28
    --- In basicstamps@egroups.com, "Jason P" <gish_jp@h...> wrote:
    > Can anyone suggest a simple h bridge design?
    >
    > Can the job be accomplished with 4 transistors and some protection
    diodes??
    > I don't have much experience with transitors and am worried about
    having to
    > find the right resistor values to bias them.
    > Also, where should any caps go to minimize trans. voltages???
    >
    > I only want to control 2 dc motor gearboxes.. I believe they are
    rated at 3
    > volts and about 0.9 amps.\

    You might want to look at some of the ICs that are available to do
    this function. Two that I have used are the TI 754410(1 amp max) and
    the Allegro UDN2998W (2amps max). These are both dual bridges. Your
    current requirements are probably a little high for the 754410 and it
    can't be heat-sinked very well since it's a DIP, but the Allegro part
    is (sort of) a dual TO220 and can be readily attached to a heat sink.
    Both include protection diodes. You can use direction control and PWM
    speed control with them if desired. There are a number of other
    similar ICs available also.

    Chuck Davis
    Oak Tree Systems
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-27 15:50
    > Can anyone suggest a simple h bridge design?
    >
    > Can the job be accomplished with 4 transistors and some protection
    > diodes?? I don't have much experience with transitors and am worried
    > about having to find the right resistor values to bias them. Also, where
    > should any caps go to minimize trans. voltages???
    >
    > I only want to control 2 dc motor gearboxes.. I believe they are rated at
    > 3 volts and about 0.9 amps.
    >

    You can roll your own, but there are several complete H-Bridge
    chips available that are so convenient and inexpensive that -unless
    you're really in it for the educational challenge- it really isn't worth
    bothering with a discrete design. The L298 is just such a chip. You
    can get just the chip $8 CAD ($5 US), or we have a complete kit
    (PCB, all parts) for under $25 CAD (about $16 US). You can see
    details and get a datasheet at:

    http://www.hvwtech.com/robotics.htm


    Mark Hillier
    President, HVW Technologies Inc.
    Mark@H...
    Tel[noparse]:([/noparse]403)730-8603 Fax[noparse]:([/noparse]403)730-8903
    Visit our web site: http://www.hvwtech.com
    Enter the BEAM/WCRG Millennium Robot Games: http://www.robotgames.com
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-27 16:13
    Read: http://www.bobblick.com/bob/projects/hbridge/index.html

    Regards,

    Al Williams
    AWC
    * 8 channels of PWM: http://www.al-williams.com/awce/pak5.htm


    >
    Original Message
    > From: Jason P [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=MBHTNYDmiOKq0t8Ynpq-nboFpzWnpZrGM0-nk9XEJe3ZlDH4YuA43Gf8g_QdVPGXGEi2EEwJ7_oOn9d2hw]gish_jp@h...[/url
    > Sent: Monday, June 26, 2000 9:55 PM
    > To: basicstamps@egroups.com
    > Subject: [noparse][[/noparse]basicstamps] h bridge control
    >
    >
    > Can anyone suggest a simple h bridge design?
    >
    > Can the job be accomplished with 4 transistors and some
    > protection diodes??
    > I don't have much experience with transitors and am worried about
    > having to
    > find the right resistor values to bias them.
    > Also, where should any caps go to minimize trans. voltages???
    >
    > I only want to control 2 dc motor gearboxes.. I believe they are
    > rated at 3
    > volts and about 0.9 amps.
    >
    > Thanks
    > ________________________________________________________________________
    > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-27 16:19
    At 10:54 PM 6/26/00 -0400, you wrote:
    >Can anyone suggest a simple h bridge design?

    You'll find several H-Bridge examples in our EDE1204 datasheet - some using
    NPN & PNP, and even one that uses only NPN. It's available for download in
    the 'Integrated Circuits' section at http://www.elabinc.com


    Todd Peterson
    E-Lab Digital Engineering, Inc.

    www.elabinc.com
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-27 16:46
    >Can the job be accomplished with 4 transistors and some protection
    diodes??
    >I don't have much experience with transitors and am worried about having
    to
    >find the right resistor values to bias them.
    >Also, where should any caps go to minimize trans. voltages???
    >I only want to control 2 dc motor gearboxes.. I believe they are rated at
    3
    >volts and about 0.9 amps.

    http://www.bobblick.com/bob/projects/hbridge/index.html
  • ArchiverArchiver Posts: 46,084
    edited 2000-06-27 16:55
    Here's a really good one. It's strong, easy to build, and forgiving of
    mistakes. And, Bob is a big help if you have trouble. Guess you'd need one
    for each motor though.

    http://bobblick.com/bob/projects/hbridge/index.html

    Greg
    Original Message
    From: Jason P <gish_jp@h...>
    To: <basicstamps@egroups.com>
    Sent: Monday, June 26, 2000 7:54 PM
    Subject: [noparse][[/noparse]basicstamps] h bridge control


    > Can anyone suggest a simple h bridge design?
    >
    > Can the job be accomplished with 4 transistors and some protection
    diodes??
    > I don't have much experience with transitors and am worried about having
    to
    > find the right resistor values to bias them.
    > Also, where should any caps go to minimize trans. voltages???
    >
    > I only want to control 2 dc motor gearboxes.. I believe they are rated at
    3
    > volts and about 0.9 amps.
    >
    > Thanks
    > ________________________________________________________________________
    > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
    >
    >
    >
    >
    >
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