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Increasing maximum current but keeping voltage same

Discussion in 'General Electronics Discussion' started by Caspar Valentine, Jun 13, 2017.

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  1. Caspar Valentine

    Caspar Valentine

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    Jun 13, 2017
    Hi, I've got a 0-5V 5MHz (high frequency for a smoother analogue signal) PWM signal that can provide a maximum of 30mA, that goes into a low pass filter so I can convert it into an analogue signal.

    I want to be able to draw up to 2A (without overheating or setting it on fire of course). I could just put a transistor, but correct me if I'm wrong, but the voltage drop across a transistor varies depending on the current drawn, and I need to know the exact voltage vs the PWM cycle.

    Is there any circuits or chips that'll let me do this? Thank you
     
  2. davenn

    davenn Moderator

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    Sep 5, 2009
    how much current is drawn is set by the load resistance
    if the voltage and the load resistance are fixed, then the current will also be fixed
     
  3. Caspar Valentine

    Caspar Valentine

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    Jun 13, 2017
    The load resistance varies. I want the voltage to be fixed, the same before and after the transistor, but the current to vary with the load resistance.
     
  4. davenn

    davenn Moderator

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    Sep 5, 2009
    OK it way beyond time you supplied a circuit diag to show us what you are trying to achieve
     
  5. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    It is still important to know the max. current as requested by dave in post #2.
    Any analog amplifier with gain=1 and able to support the max. current required will be suitable for this application.

    Note that this will incur a comparatively high cost in terms of power dissipation in the linear amplifier, thwarting the use of pwm as a means of saving power.
     
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