Re: missed keystrokes problem, back with a vengeance.
- To: debian-arm@lists.debian.org
- Subject: Re: missed keystrokes problem, back with a vengeance.
- From: Jerry Stuckle <jstuckle@attglobal.net>
- Date: Wed, 1 Feb 2017 23:06:51 -0500
- Message-id: <[🔎] 1fa01763-0046-06a7-2e88-b8a80ed55327@attglobal.net>
- In-reply-to: <201701291348.50931.gheskett@shentel.net>
- References: <201701290847.42172.gheskett@shentel.net> <VI1PR0901MB1598C7EB5F145677FC7CE68898480@VI1PR0901MB1598.eurprd09.prod.outlook.com> <CAOh3dDa=_OpS1w6UXXUt8Sxe_t+k90ALfm=NEC++vmXhAECmLQ@mail.gmail.com> <201701291348.50931.gheskett@shentel.net>
On 1/29/2017 1:48 PM, Gene Heskett wrote:
>
> Alan, ALL of the motor drivers are switchmode, with the current
> regulation running at or above 20 KHz. And these noise spikes are
> ringing at nominally 100 MHz. I have managed to get the xy motor noise
> under control by takeing out the switchmode psu's, and putting in
> tordoid transformers, bridge rectifiers, and the biggest electrolytic I
> had in the drawers that had sufficient withstand voltage. Its a star
> ground system, and the output cables to the motors are shielded, and the
> shield grounded as it goes by this single bolt ground on its way out of
> the box. The shielding extends both ways from that point but is not
> connected either at the motor, or at the driver, just at the bolt. This
> is std in such noisy machinery.
>
I would also recommend bypassing those electrolytics with 0.01uf or so
disk capacitors (or similar). Electrolytics have higher impedance at
higher frequencies. Bypass capacitors help with high frequency spikes.
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