On Fri, 23 Apr 2021, andrew beck wrote:
Date: Fri, 23 Apr 2021 16:23:35 +1200
From: andrew beck <andrewbeck0...@gmail.com>
Reply-To: "Enhanced Machine Controller (EMC)"
<emc-users@lists.sourceforge.net>
To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net>
Subject: Re: [Emc-users] wiring up mesa ency encoder
update on encoder splitting to altivar vfd and mesa card
hey guys just a update and a few more questions
so I managed to get the encoder mounted on my spindle and working fine.
the vfd works in closed loop control now and I get quite nice power control
at almost zero rpm its great actually.
now I need to get that encoder output into my mesa card
the encoder I have can have any voltage from 5/25 and output equals input.
the vfd senses low state at under 1.5 and high state at over 7.7v
the vfd sends 12v out into encoder currently
so my plan is to just put a resistor in series on the 12 v out to encoder
to bring the power down to 10v or so. then the mesa ency card will work I
think and I can split off the feedback to the mesa card and get the
orientation in linuxcnc working and rigid tapping.
so big question is what value of resistor do i need to bring the volts down
a bit.
regards
Andrew
Rather than a resistor, I would use a few diodes to drop the voltage
since the diode drop is mostly independent of current.
3 1N4001 diodes in series would drop the voltage to about 10V
On Sat, Apr 17, 2021 at 1:11 AM andrew beck <andrewbeck0...@gmail.com>
wrote:
Question on that.
My vfd encoder card reads encoder pulses at above 7v and under 5v I think.
My encoder I bought from a company in China which made it for me. It can
do 10k rpm. And accepts 5-24v input. Output just corresponds to whatever
the input value is. So maybe one solution is drop the voltage down to 10v
from vfd and then that is a bit safer.
And I just read that my particular vfd encoder card doesn't output the
encoder pulses. So I definitely have to tee onto the line. I bought them
as they were the only ones cheap on ebay. They rest were so expensive. Or
unavailable
I'll post up the encoder card manual tomorrow.
First steps are to get the vfd working in closed loop vector control with
the encoder. Then I can try getting the logic into Linuxcnc. It's rough
but worst case I put two encoders onto the spindle lol.. I have several
laying around. One is a nice 5v ttl one that is 5000 ppr.
On Fri, 16 Apr 2021, 7:41 PM andy pugh, <bodge...@gmail.com> wrote:
On Fri, 16 Apr 2021 at 07:25, andrew beck <andrewbeck0...@gmail.com>
wrote:
> if manual says I can run up to 13v do you think I will be fine?
I am not PCW, but I would be nervous about 12V with an absolute max of 12.
Maybe you can use one of the tiny buck-converters from eBay to supply
the encoder with 5V (or 8V) from the 12V?
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
?? George Fitch, Atlanta Constitution Newspaper, 1912
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Peter Wallace
Mesa Electronics
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