From: David VanHorn <microbrix@gmail.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Sun, 19 Apr 2020 23:25:04 -0700
Subject: Re: [EE] LDO reg keeps failing. Looking for suggestions.
Thread-Topic: [EE] LDO reg keeps failing. Looking for suggestions.
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If vcc can rise above the input then most pnp regulators will fail


On Sun, Apr 19, 2020, 11:44 PM James Burkart <james@burkartstudios.com>
wrote:

> Hey everyone! Here's a little motor driver board I made that works great,
> until it doesn't. The voltage regulator keeps failing on me. I've used a
> couple different LDO regulators and it always happens. It's always at
> random times. So I am pretty sure it's EMI from the brushed motors. If
> someone here has a few minutes, could you look over my schematic and
> recommend changes?
>
> The board is powered from a 2S lipo, so 6.5 to 8.2V. For the flywheel
> output there are 2 motors in parallel that draw about 3A total when
> running, and a stall current of about 20A. The pusher output runs 1 motor
> that draws about 100mA with a stall current of about 3A. I do use PWM to
> control the speed of the pusher motor.
>
> If you're wondering, this driver board is for flywheel Nerf blasters.
>
> --
> Sincerely,
>
> James Burkart
> *925.667.7175*
>
> *Schematic:*
> https://drive.google.com/file/d/1dgLf3sFNzFxvEuzaqTuIHd4_VSUfNbg8
> --
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