From: Sean Breheny <shb7@cornell.edu>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Sat, 25 Jan 2020 19:32:44 -0800
Subject: Re: [EE] H-Bridge supply voltage spike only in "reverse" (not
 forward)
Thread-Topic: [EE] H-Bridge supply voltage spike only in "reverse" (not
 forward)
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I agree - beware that power supplies which are isolated from earth ground
may still have substantial capacitance to ground which can affect circuits
when you ground one of the nodes in the circuit.

On Sat, Jan 25, 2020 at 5:58 PM Jason White <
whitewaterssoftwareinfo@gmail.com> wrote:

> Isolated differential probe for Vunregulated and "directly connected"
> for PWM pulses out of H-Bridge. Power supply is isolated from earth
> ground.
>
> I suppose I should try just the differential probe.
>
> On Sat, Jan 25, 2020 at 5:22 PM Sean Breheny <shb7@cornell.edu> wrote:
> >
> > How are you measuring  the voltage across the H-bridge? Are you using a
> > differential probe? If not, where is the probe GND connected?
>
> -Jason White
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