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  • Topic: H Bridge for Tortoise

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    • January 2, 2018 1:58 PM EST
      • Candlewood Valley, Connecticut
         
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      So zactly what is the difference between an H Bridge motor controller and an Electronic Speed control (ESC) ?   I've done some recent experiments with a real cheap ESC and want to try something better. I know the bridge you are referencing is driven by an Audrino and is designed for stepper motors, but I have also seen them advertised for standard motors driven by an RC Servo output which is how I would use it.

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    • January 2, 2018 2:34 PM EST
      • Kittery, ME
         
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      The H bridge itself simply provides control over the polarity of its output. For the tortoise motor, the polarity determines the direction of travel. I am not doing any kind of speed control, since it's already quite slow.

      Most ESCs designed for RC applications translate a servo signal to a 0% -100% duty cycle PWM output.   They integrate an H bridge for directional control.  If you were to drive an H Bridge directly with a servo signal, the DC motor would never turn off or reach 100%, as the minimum pulse width for a servo is 1 ms and the maximum is 2 ms, at 50 Hz. The board that I linked above expects a raw PWM signal. In my case, I am just sending it a logic signal (essentially 100% duty cycle). 

      This post was edited by Eric Reuter at January 2, 2018 5:06 PM EST
    • January 2, 2018 3:41 PM EST
      • Candlewood Valley, Connecticut
         
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      Thanks - I guess my terminology hasn't caught up with my idea factory.  What I was calling simply an H-Bridge is really a "Single channel H-bridge speed controller - 10A, 6.5V to 28V"  So I are now a bit more edumacated.  Thanks!

       

       

       

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    • January 2, 2018 4:46 PM EST
      • Carlsbad, CA
         
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      H bridge is really the design, where the schematic looks like an "H", although you can buy an IC that has an H bridge circuit inside.

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