Re: missed keystrokes problem, back with a vengeance.
On Wednesday 01 February 2017 17:41:00 Luke Kenneth Casson Leighton
wrote:
> On Sun, Jan 29, 2017 at 6:48 PM, Gene Heskett <gheskett@shentel.net>
wrote:
> > On Sunday 29 January 2017 12:40:21 Alan Corey 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'm going to be looking at setting up an open hardware lathe and cnc
> machine at some point, so i'm really delighted to see what you're
> doing... i'm just really very confused as to why you're using such a
> low-cost board from a *known* unethical fabless semiconductor company
> to control such really very expensive equipment. just sayin.
>
> anyway: when working for Path Intelligence we learned the hard way
> about R.F. and EMI interference, so we had to nickel-copper paint the
> entire interior of the IP66 box and replace its rubber gasket in the
> lid with a conducting one.
>
> we also got a 2nd-hand spectrum analyser, our resident expert made a
> probe out of a single 20mm loop of copper wire exactly like you see in
> the fairground attractions in days of yore, and we could confirm
> immediately the effectiveness of anything that we tried to do. which
> was really *really* effective in the case of the nickel-copper spray.
>
> i can therefore strongly recommend trying the same thing... but
> honestly, the cost of all this equipment should be far in excess of
> just replacing the entire board, including the processor that's made
> by the unethical company known as broadcom, so i have to ask,
> particularly given that it's so problematic, if you'd given that some
> thought as a first priority rather than a last?
>
> l.
Because its cheap at $35, the interface card is only $60 USD, and once
the noise is nailed down, has the feel of something that will run until
the next power bump. And right past that if I put a small ups on it as I
have a 20kw nat gas fired standby just outside the back door? The ups
would only have to hold up 3 or 4 seconds while the standby fires up.
Where else can you get a machine controller capable of carving a Toyota
racing engine out of a solid alu casting at a rate to keep up with the
TRO demand?
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
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