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Trailer brake controller - ground current.

Discussion in 'Automotive Electronics' started by Diver300, May 21, 2017.

  1. Diver300

    Diver300 Well-Known Member

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    I'm looking into the fitting of electric trailer brake controllers.

    I know that there can be quite a lot of current in the trailer brake wire, especially if there are several axles.

    Can anyone tell me what happens when the braking power is reduced? Does the brake controller work like an adjustable linear regulator, or like an adjustable buck controller, possibly using the brake coils themselves as the inductor? The linear regulator will get hot, while the buck controller will have quite a large ground current.

    Are there freewheel diodes in the brake coils?

    Or is the output of the brake controller a PWM output?

    Have I misunderstood the situation?
     
  2. debe

    debe Active Member

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    Generaly PWM controlled.
     
  3. MikeMl

    MikeMl Well-Known Member Most Helpful Member

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    High-side PWM. The current through the wheel brakes returns through the trailer Ground wire. Probably a snubber diode (anode to vehicle Ground, cathode to Brake line) inside the Brake Controller (none in trailer).

    I am using this one:
     
  4. dave

    Dave New Member

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  5. shokjok

    shokjok Member

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    Your trailer design isn't stated. Will the intended trailer brake controller operate more than two wheels? You don't want to overload either the trailer or the brake controller and lose control of the situation.
     

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