Re: [Emc-users] hypothetical, maybe not, switching psu question

[Gene Heskett]

On Wednesday 20 May 2020 00:03:37 John Dammeyer wrote:

> > -Original Message-
> > From: Gene Heskett [mailto:ghesk...@shentel.net]
> > Sent: May-19-20 1:50 PM
> > To: emc-users@lists.sourceforge.net
> > Subject: Re: [Emc-users] hypothetical, maybe not, switching psu
> > question
> >
> > On Tuesday 19 May 2020 15:44:51 John Dammeyer wrote:
> > > Hi Gene,
> > > Since I'm running DC Servos I wanted the ability to clamp the back
> > > emf from a decelerating motor.  I built a small circuit that
> > > sensed both high voltage and AC power.   It puts a resistor across
> > > the DC rail to pull it down and the resistor is connected with
> > > both a relay and a FET in parallel.
> > >
> > > When power vanishes the relay is de-energized and the 105VDC power
> > > supply is quickly drained through the NC connection on the relay. 
> > > The FET does the same but at high speeds to avoid that over
> > > voltage condition.
> > >
> > > Since the little PIC processor senses AC voltage it can also run a
> > > relay on a second small board that switches across an inrush
> > > resistor. The advantage over a high power thermistor is no heat
> > > and you can cycle power without worrying about the inrush
> > > thermistor still being way too hot and therefore too low a
> > > resistance.
> > >
> > > Schematics attached.
> >
> > Both would seem to be more complex than a few lines of hal code I
> > can easily write.
>
> Hey Gene,
> That might be unless your PC dies or locks up.  But even more
> important, in my case I'm running dual boot and there is no HAL file
> for MACH3.
>
I looked at MACH3 as it came with a demo copy for the 6040.  Found it 
couldn't control the spindle at all, and went and got the computer and 
all the motor drivers stuff that was driving the teeny hf mill and 
hooked it up to the 6040's motors. All works, and about 190 ipm faster 
than the crap that came with it in that honking big box you see in the 
adverts.  When I confronted the vendor about it he just shrugged.

Do not buy a 6040 without expecting to buy all new drivers folks.  w/o 
them, it's worth maybe 800$, not the almost $1200 I paid.

> Besides.  I don't think safety critical stuff should depend on the PC.

This is true. But its zero cost.  And I'm aware of that safety stuff too.

> John
>
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Triggering an external relay from a BOB

[Gene Heskett]

On Tuesday 19 May 2020 20:58:45 Dan Henderson wrote:

> I have encoder.0.position-scale set to 400 and I have all three phases
> A,B,Z enabled as inputs. Me thinks it might have to do with
> pwmgen.0.scale or the pwmgen.0.offset. Not entirely sure what those do
> yet. I believe scale assumes you know the max rpm the motor will run
> and sets the increments accordingly by PWM percentage. I'm not real
> clear on it. The command speed of say 1000 rpm is very close to the
> Pypanel display speed. Any value below 1000 in the panel is suspect.

I found the linearity of speed control was much better if I used a large 
R between the analog output of my spinx1, and the former location that 
the slider arm from the speed control connects to.  Try something in the 
47k to 100k range. That point seems to be the summing point of the 
feedback loop and you won't see a huge voltage there, as it drives that 
point to a reference voltage, in order to get an error voltage that 
actually drives it.  Drive that point with too low a source R, and it 
will go wide open rapidly without good control at the lower speeds.  
That point it at the hot side of the line so be very carefull not to 
ever ground it.  That lets out all the smoke and it doesn't work 
anymore.

Rule of thumb, if it gets to full speed before the spinx1 gets to 10 
volts, scale up that "buildout resistor" accordingly.  It likely still 
won't be linear, but it will be a lot better, with stiffer control at 
the reduced speed settings.

The spinx1 is a mesa gizmo that isolates that control voltage from 
ground.  Theres a bunch of those available on the net from various 
suppliers, but the mesa spinx1 is generally the lowest priced and best 
engineered on of the lot.  I'm useing one of them to control the vfd on 
my Sheldon 11x54 lathe.  And there it works very well.

I am not using one on the aftermarket clone vfd I put on the 6040, when I 
found the onethat came with it was not capable of being controlled.

There I am feeding the output wave of the pwm-gen directly to that 
electronic resistor function in a 7i76, and its very linear.  And I'll 
burn my fingers trying to stop it at any any speed above around 200 
rpms.  And its a 24k rpms motor, so I was pleasantly surprised once I 
had found the right register to turn up the low speed motor current to 
that motors nameplate FLA.  But now I've rigged a mister for coolant, 
and can spin it up nicely while cutting alu.

Rule of thumb for cutting alu, if its heating the work enough to detect 
it getting warm when you touch it, its too hot, get a coolant mist on 
the tool.

> On Tue, May 19, 2020 at 6:54 PM Gene Heskett  
wrote:
> > On Tuesday 19 May 2020 18:16:49 Dan Henderson wrote:
> > > The CUI ATM 103. The PPR is set at 100 both on the device and in
> > > HAL. I’m not using scale mode since I needed Quadrature in order
> > > to detect CCW for rigid tapping.
> >
> > You should be able to set encoder scale at 400 w/o effecting the
> > quadrature direction sensing. But I've no experience with how CUI
> > does it.  All the encoders I have built fed either software or mesa
> > in quadrature modes. ABX outputs IOW. I've only one commercially
> > made one, an omron 1000 line but it's not on the spindle, it's on
> > the motor but the index still comes from the spindle.  So the scale
> > changes with the backgear. Works well.
> >
> > > On Tue, May 19, 2020 at 5:03 PM Gene Heskett
> > > 
> >
> > wrote:
> > > > On Tuesday 19 May 2020 17:28:40 Dan Henderson wrote:
> > > > > Thanks Gene.  I too dabbled in Amiga ARexx back in the day. I
> > > > > was / still am a Commodore aficionado. To this day, I have
> > > > > working Amiga, C-128, and C64 hardware. I prefer Assembly
> > > > > Language over BASIC for obvious reasons with speed being
> > > > > foremost among them. But I digress...
> > > > >
> > > > > I ended up building a reversing cirucuit with a Tyco 12v DPDT
> > > > > relay capable of 15a / 30 VDC switching. So long as I don't
> > > > > attempt a direction flip that exceeds those max ratings I
> > > > > should be good. I've tested 800 rpm CW - CCW -CW without so
> > > > > much as a batted eye -- it was quite smooth with the delays
> > > > > factored in and all. Quite happy with this setup. I have the
> > > > > added bonus of a semi brake action on the CCW motion. An M5
> > > > > will stop that rotation quite quickly due to the the mc2100
> > > > > power off which kills the slow decell ramp built-in with that
> > > > > board.
> > > > >
> > > > > Now to move on and dial-in the RPM reading in PY Panel. My
> > > > > scale / range is not set right. I can turn the RPM at 50 or
> > > > > less and it shows 200 rpm on the Pypanel.
> > > >
> > > > What do you have for an encoder? Remember, a 50 slot opto disk
> > > > is actually 200 "edges" which is what you may be displaying.
> > > > Depends on the mode the encoder is running in.
> > > >
> > > > > Cheers!
> > > >
> > > > Cheers, Gene Heskett
> > > > --
> > > > "There are four 

Re: [Emc-users] hypothetical, maybe not, switching psu question

[John Dammeyer]

> -Original Message-
> From: Gene Heskett [mailto:ghesk...@shentel.net]
> Sent: May-19-20 1:50 PM
> To: emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] hypothetical, maybe not, switching psu question
> 
> On Tuesday 19 May 2020 15:44:51 John Dammeyer wrote:
> 
> > Hi Gene,
> > Since I'm running DC Servos I wanted the ability to clamp the back emf
> > from a decelerating motor.  I built a small circuit that sensed both
> > high voltage and AC power.   It puts a resistor across the DC rail to
> > pull it down and the resistor is connected with both a relay and a FET
> > in parallel.
> >
> > When power vanishes the relay is de-energized and the 105VDC power
> > supply is quickly drained through the NC connection on the relay.  The
> > FET does the same but at high speeds to avoid that over voltage
> > condition.
> >
> > Since the little PIC processor senses AC voltage it can also run a
> > relay on a second small board that switches across an inrush resistor.
> >  The advantage over a high power thermistor is no heat and you can
> > cycle power without worrying about the inrush thermistor still being
> > way too hot and therefore too low a resistance.
> >
> > Schematics attached.
> >
> Both would seem to be more complex than a few lines of hal code I can
> easily write. 

Hey Gene,
That might be unless your PC dies or locks up.  But even more important, in my 
case I'm running dual boot and there is no HAL file for MACH3.

Besides.  I don't think safety critical stuff should depend on the PC.

John




___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] SPAM: hypothetical, maybe not, switching psu question

[Ed]

On 5/19/20 5:09 PM, andy pugh wrote:

On Tue, 19 May 2020 at 21:35, Todd Zuercher  wrote:

Are  you sure your 40 amp SSR was what it claimed it was.   I recall someone on 
this list telling a story about how he opened up some inexpensive SSRs to find 
woefully under spec-ed internal components (like 1/4th the units rated 
capacity).

I had some 40A SSRs with a 15A device inside that blew at 2A.

Reminds me of the assortment packs from RadioShack, The fine print said 
the items may not meet mfg specs. IOW, floor sweepings.



Ed.




___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Triggering an external relay from a BOB

[Dan Henderson]

I have encoder.0.position-scale set to 400 and I have all three phases
A,B,Z enabled as inputs. Me thinks it might have to do with pwmgen.0.scale
or the pwmgen.0.offset. Not entirely sure what those do yet. I believe
scale assumes you know the max rpm the motor will run and sets the
increments accordingly by PWM percentage. I'm not real clear on it. The
command speed of say 1000 rpm is very close to the Pypanel display speed.
Any value below 1000 in the panel is suspect.

On Tue, May 19, 2020 at 6:54 PM Gene Heskett  wrote:

> On Tuesday 19 May 2020 18:16:49 Dan Henderson wrote:
>
> > The CUI ATM 103. The PPR is set at 100 both on the device and in HAL.
> > I’m not using scale mode since I needed Quadrature in order to detect
> > CCW for rigid tapping.
>
> You should be able to set encoder scale at 400 w/o effecting the
> quadrature direction sensing. But I've no experience with how CUI does
> it.  All the encoders I have built fed either software or mesa in
> quadrature modes. ABX outputs IOW. I've only one commercially made one,
> an omron 1000 line but it's not on the spindle, it's on the motor but
> the index still comes from the spindle.  So the scale changes with the
> backgear. Works well.
>
> > On Tue, May 19, 2020 at 5:03 PM Gene Heskett 
> wrote:
> > > On Tuesday 19 May 2020 17:28:40 Dan Henderson wrote:
> > > > Thanks Gene.  I too dabbled in Amiga ARexx back in the day. I was
> > > > / still am a Commodore aficionado. To this day, I have working
> > > > Amiga, C-128, and C64 hardware. I prefer Assembly Language over
> > > > BASIC for obvious reasons with speed being foremost among them.
> > > > But I digress...
> > > >
> > > > I ended up building a reversing cirucuit with a Tyco 12v DPDT
> > > > relay capable of 15a / 30 VDC switching. So long as I don't
> > > > attempt a direction flip that exceeds those max ratings I should
> > > > be good. I've tested 800 rpm CW - CCW -CW without so much as a
> > > > batted eye -- it was quite smooth with the delays factored in and
> > > > all. Quite happy with this setup. I have the added bonus of a semi
> > > > brake action on the CCW motion. An M5 will stop that rotation
> > > > quite quickly due to the the mc2100 power off which kills the slow
> > > > decell ramp built-in with that board.
> > > >
> > > > Now to move on and dial-in the RPM reading in PY Panel. My scale /
> > > > range is not set right. I can turn the RPM at 50 or less and it
> > > > shows 200 rpm on the Pypanel.
> > >
> > > What do you have for an encoder? Remember, a 50 slot opto disk is
> > > actually 200 "edges" which is what you may be displaying. Depends on
> > > the mode the encoder is running in.
> > >
> > > > Cheers!
> > >
> > > 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)
> > > If we desire respect for the law, we must first make the law
> > > respectable. - Louis D. Brandeis
> > > Genes Web page 
> > >
> > >
> > > ___
> > > Emc-users mailing list
> > > Emc-users@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
> 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)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] SPAM: hypothetical, maybe not, switching psu question

[andy pugh]

On Wed, 20 May 2020 at 00:36, Gene Heskett  wrote:

> > I had some 40A SSRs with a 15A device inside that blew at 2A.
>
> Do you recall the brand label?

The label was "Fotek" But I doubt that they were by Fotek.

-- 
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


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Triggering an external relay from a BOB

[Gene Heskett]

On Tuesday 19 May 2020 18:16:49 Dan Henderson wrote:

> The CUI ATM 103. The PPR is set at 100 both on the device and in HAL.
> I’m not using scale mode since I needed Quadrature in order to detect
> CCW for rigid tapping.

You should be able to set encoder scale at 400 w/o effecting the 
quadrature direction sensing. But I've no experience with how CUI does 
it.  All the encoders I have built fed either software or mesa in 
quadrature modes. ABX outputs IOW. I've only one commercially made one, 
an omron 1000 line but it's not on the spindle, it's on the motor but 
the index still comes from the spindle.  So the scale changes with the 
backgear. Works well.

> On Tue, May 19, 2020 at 5:03 PM Gene Heskett  
wrote:
> > On Tuesday 19 May 2020 17:28:40 Dan Henderson wrote:
> > > Thanks Gene.  I too dabbled in Amiga ARexx back in the day. I was
> > > / still am a Commodore aficionado. To this day, I have working
> > > Amiga, C-128, and C64 hardware. I prefer Assembly Language over
> > > BASIC for obvious reasons with speed being foremost among them.
> > > But I digress...
> > >
> > > I ended up building a reversing cirucuit with a Tyco 12v DPDT
> > > relay capable of 15a / 30 VDC switching. So long as I don't
> > > attempt a direction flip that exceeds those max ratings I should
> > > be good. I've tested 800 rpm CW - CCW -CW without so much as a
> > > batted eye -- it was quite smooth with the delays factored in and
> > > all. Quite happy with this setup. I have the added bonus of a semi
> > > brake action on the CCW motion. An M5 will stop that rotation
> > > quite quickly due to the the mc2100 power off which kills the slow
> > > decell ramp built-in with that board.
> > >
> > > Now to move on and dial-in the RPM reading in PY Panel. My scale /
> > > range is not set right. I can turn the RPM at 50 or less and it
> > > shows 200 rpm on the Pypanel.
> >
> > What do you have for an encoder? Remember, a 50 slot opto disk is
> > actually 200 "edges" which is what you may be displaying. Depends on
> > the mode the encoder is running in.
> >
> > > Cheers!
> >
> > 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)
> > If we desire respect for the law, we must first make the law
> > respectable. - Louis D. Brandeis
> > Genes Web page 
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] SPAM: hypothetical, maybe not, switching psu question

[Gene Heskett]

On Tuesday 19 May 2020 18:09:37 andy pugh wrote:

> On Tue, 19 May 2020 at 21:35, Todd Zuercher  
wrote:
> > Are  you sure your 40 amp SSR was what it claimed it was.   I recall
> > someone on this list telling a story about how he opened up some
> > inexpensive SSRs to find woefully under spec-ed internal components
> > (like 1/4th the units rated capacity).
>
> I had some 40A SSRs with a 15A device inside that blew at 2A.

Do you recall the brand label? And more importantly, what was the load 
device?

I had, when I was the CE at WDTV, a studio lighting control with 36 3k 
watt channels, full of crydom 30 amp SSR's.  The studio, since I've 
retired has better cameras and much of its lighting in now led based 
except the overheads which are now various types of HO CCFL's. But in my 
18 years there I had probably 6 or 7 cd4000 logic chip failures in the 
control panel, and zero SSR failures.  Patch cord burnups, several, but 
no SSR failures.  I came to the conclusion that crydom makes very good 
stuff.  Other brands not so lucky maybe. IDK, this one blown shorted is 
the first failure I have had of any of this "style" of SSR's. When I 
have removed it and built the soft start in its place and have it 
working I may grind this one open and report what I find, if by then my 
back still feels like messing with it. Since I'll be 3 steps up a ladder 
doing all that, doubtfull.

Thanks Andy & Todd.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Triggering an external relay from a BOB

[Dan Henderson]

The CUI ATM 103. The PPR is set at 100 both on the device and in HAL. I’m
not using scale mode since I needed Quadrature in order to detect CCW for
rigid tapping.



On Tue, May 19, 2020 at 5:03 PM Gene Heskett  wrote:

> On Tuesday 19 May 2020 17:28:40 Dan Henderson wrote:
>
> > Thanks Gene.  I too dabbled in Amiga ARexx back in the day. I was /
> > still am a Commodore aficionado. To this day, I have working Amiga,
> > C-128, and C64 hardware. I prefer Assembly Language over BASIC for
> > obvious reasons with speed being foremost among them. But I digress...
> >
> > I ended up building a reversing cirucuit with a Tyco 12v DPDT relay
> > capable of 15a / 30 VDC switching. So long as I don't attempt a
> > direction flip that exceeds those max ratings I should be good. I've
> > tested 800 rpm CW - CCW -CW without so much as a batted eye -- it was
> > quite smooth with the delays factored in and all. Quite happy with
> > this setup. I have the added bonus of a semi brake action on the CCW
> > motion. An M5 will stop that rotation quite quickly due to the the
> > mc2100 power off which kills the slow decell ramp built-in with that
> > board.
> >
> > Now to move on and dial-in the RPM reading in PY Panel. My scale /
> > range is not set right. I can turn the RPM at 50 or less and it shows
> > 200 rpm on the Pypanel.
>
> What do you have for an encoder? Remember, a 50 slot opto disk is
> actually 200 "edges" which is what you may be displaying. Depends on the
> mode the encoder is running in.
>
> > Cheers!
> >
>
> 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)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] SPAM: hypothetical, maybe not, switching psu question

[andy pugh]

On Tue, 19 May 2020 at 21:35, Todd Zuercher  wrote:
>
> Are  you sure your 40 amp SSR was what it claimed it was.   I recall someone 
> on this list telling a story about how he opened up some inexpensive SSRs to 
> find woefully under spec-ed internal components (like 1/4th the units rated 
> capacity).

I had some 40A SSRs with a 15A device inside that blew at 2A.

-- 
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


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Triggering an external relay from a BOB

[Gene Heskett]

On Tuesday 19 May 2020 17:28:40 Dan Henderson wrote:

> Thanks Gene.  I too dabbled in Amiga ARexx back in the day. I was /
> still am a Commodore aficionado. To this day, I have working Amiga,
> C-128, and C64 hardware. I prefer Assembly Language over BASIC for
> obvious reasons with speed being foremost among them. But I digress...
>
> I ended up building a reversing cirucuit with a Tyco 12v DPDT relay
> capable of 15a / 30 VDC switching. So long as I don't attempt a
> direction flip that exceeds those max ratings I should be good. I've
> tested 800 rpm CW - CCW -CW without so much as a batted eye -- it was
> quite smooth with the delays factored in and all. Quite happy with
> this setup. I have the added bonus of a semi brake action on the CCW
> motion. An M5 will stop that rotation quite quickly due to the the
> mc2100 power off which kills the slow decell ramp built-in with that
> board.
>
> Now to move on and dial-in the RPM reading in PY Panel. My scale /
> range is not set right. I can turn the RPM at 50 or less and it shows
> 200 rpm on the Pypanel.

What do you have for an encoder? Remember, a 50 slot opto disk is 
actually 200 "edges" which is what you may be displaying. Depends on the 
mode the encoder is running in.

> Cheers!
>

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Triggering an external relay from a BOB

[Dan Henderson]

Thanks Gene.  I too dabbled in Amiga ARexx back in the day. I was / still
am a Commodore aficionado. To this day, I have working Amiga, C-128, and
C64 hardware. I prefer Assembly Language over BASIC for obvious reasons
with speed being foremost among them. But I digress...

I ended up building a reversing cirucuit with a Tyco 12v DPDT relay capable
of 15a / 30 VDC switching. So long as I don't attempt a direction flip that
exceeds those max ratings I should be good. I've tested 800 rpm CW - CCW
-CW without so much as a batted eye -- it was quite smooth with the delays
factored in and all. Quite happy with this setup. I have the added bonus of
a semi brake action on the CCW motion. An M5 will stop that rotation quite
quickly due to the the mc2100 power off which kills the slow decell ramp
built-in with that board.

Now to move on and dial-in the RPM reading in PY Panel. My scale / range is
not set right. I can turn the RPM at 50 or less and it shows 200 rpm on the
Pypanel.

Cheers!




On Tue, May 19, 2020 at 4:01 PM Gene Heskett  wrote:

> On Tuesday 19 May 2020 16:15:31 Dan Henderson wrote:
>
> > Update for everyone. I now have two working relays controlling the
> > operation of the spindle motor via BOB and Parallel Port. I've also
> > now successfully tested the G33.1 Rigid Tapping cycle with this setup.
> >
> > Relay #1 is used to power on/off the motor controller board (MC2100).
> > (M5 or S0 triggers off, M3 or M4 triggers on)
> > Relay #2 is used to reverse the polarity of the spindle motor
> > providing CCW operation. (M4 Triggers on, M3 or M5 triggers off)
> >
> > In order to get these functioning properly, I had to implement two
> > different "timerdelay" functions in HAL.
> > One delay is needed to allow the MC2100 board to power on and
> > initialize before PWM signals are sent.
> >
> > The second delay is needed to slow down the reverse polarity relay in
> > order to ensure the motor controller is properly powered off before
> > allowing the relay to flip back to normal polarity. Otherwise the
> > spindle would flip rotation to cw once triggered.
>
> Glad you have it sorted. :)
>
> > HAL may not be the easiest to understand, but it can do some amazing
> > work if you figure it out!
> >
> I have only found one other language more versatile than hal, arexx on
> the amiga, but it had hooks into the deepest workings of amigados that
> hal will never have. It is IMNSHO, the best language that linux itself
> will tolerate in the same building, very very little it cannot do.
>
> > Thanks for all the help on this thread!
> >
> > Dan
>
>
> 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)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] SPAM: hypothetical, maybe not, switching psu question

[Gene Heskett]

On Tuesday 19 May 2020 14:01:23 Todd Zuercher wrote:

> Are  you sure your 40 amp SSR was what it claimed it was.   I recall
> someone on this list telling a story about how he opened up some
> inexpensive SSRs to find woefully under spec-ed internal components
> (like 1/4th the units rated capacity).
>
I have that in mind, these are from mpja.com, HOYMC brand. I bought a big 
bills worth of them several years back, this was the first failure, and 
I had zero trouble talking mpja into adding a freebie to todays order 
for 5 more. I am currently useing 2 to switch the vfd power from LCNC on 
the sheldon, and 2 to time the soft start of the spindle motor supply on 
the G0704, and by the time I'm done playing, I'll be switching the 704's 
XYZA supply too.  Then TLM is next. I'm already using hard contact 
relays for all that on the 6040, but they will eventually weld shut I 
expect. I haven't really put it to work yet, heart attack got in the way 
and it took from late sept to mid January to get that all sorted.

> Todd Zuercher
> P. Graham Dunn Inc.
> 630 Henry Street 
> Dalton, Ohio 44618
> Phone:  (330)828-2105ext. 2031
>
> -Original Message-
> From: Gene Heskett 
> Sent: Tuesday, May 19, 2020 1:49 PM
> To: Enhanced Machine Controller (EMC)
>  Subject: SPAM: [Emc-users]
> hypothetical, maybe not, switching psu question
>
> [EXTERNAL EMAIL] Be sure links are safe.
>
> Greetings all;
>
> Having destroyed one 40 amp SSR by turning on the switching psu;s for
> the two running the X motors and the builtin supply of the even
> bigger drive running the Z axis, already, I am now contemplating how
> to do a soft start to limit the initial in-rush of charging up those 3
> power supplies.
>
> And doing it in a lower powered version of how I am doing the huge
> analog supply that runs the spindle motor.
>
> There, I have two timers which are controlling two 40 amp SSR's with a
> 50 ohm 200 watt resistor, so it starts charging that supply with its
> thousands of u-f's by applying the power thru that big resistor, then
> the 2nd SSR comes on applying it directly 3 seconds later.  This has
> worked flawlessly for about 4 years now.
>
> Now I have obtained two more used genuine crydom 40 amp 480 volt
> SSR's, and am considering doing the same thing in essence, only with a
> much smaller ohmage R to limit the in-rush this batch of switchers in
> a similar manner.
>
> But switchers, I have heard, need that initial bump to get started
> correctly. To that end I've also ordered a pair of 10 ohm 70 watt
> resistors, which if need be can be paralleled for 5 ohms in series
> with these supplies for the first 1/2 to 1 second.
>
> But I intend to use one of these in another analog supply, starting
> the spindle psu in The Little Monster too, putting all its heavy power
> under LCNC's control.  But that is a different project.
>
> These switchers are, or s/b all fused to protect them in the event
> they don't start.  So I don't expect a start failure to do more than
> blow the fuse.
>
> Has anyone else any experience with this, that can add gotcha's to
> watch for in such a current limited startup?  10 ohms in series with
> the power to protect the SSR's is the basic idea. 10 ohms would limit
> at 12.5 amps of in-rush, which seems reasonable.
>
> Thanks all.
>
> 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)
> If we desire respect for the law, we must first make the law
> respectable. - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Triggering an external relay from a BOB

[Gene Heskett]

On Tuesday 19 May 2020 16:15:31 Dan Henderson wrote:

> Update for everyone. I now have two working relays controlling the
> operation of the spindle motor via BOB and Parallel Port. I've also
> now successfully tested the G33.1 Rigid Tapping cycle with this setup.
>
> Relay #1 is used to power on/off the motor controller board (MC2100).
> (M5 or S0 triggers off, M3 or M4 triggers on)
> Relay #2 is used to reverse the polarity of the spindle motor
> providing CCW operation. (M4 Triggers on, M3 or M5 triggers off)
>
> In order to get these functioning properly, I had to implement two
> different "timerdelay" functions in HAL.
> One delay is needed to allow the MC2100 board to power on and
> initialize before PWM signals are sent.
>
> The second delay is needed to slow down the reverse polarity relay in
> order to ensure the motor controller is properly powered off before
> allowing the relay to flip back to normal polarity. Otherwise the
> spindle would flip rotation to cw once triggered.

Glad you have it sorted. :)

> HAL may not be the easiest to understand, but it can do some amazing
> work if you figure it out!
>
I have only found one other language more versatile than hal, arexx on 
the amiga, but it had hooks into the deepest workings of amigados that 
hal will never have. It is IMNSHO, the best language that linux itself 
will tolerate in the same building, very very little it cannot do.
  
> Thanks for all the help on this thread!
>
> Dan


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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] hypothetical, maybe not, switching psu question

[Gene Heskett]

On Tuesday 19 May 2020 15:44:51 John Dammeyer wrote:

> Hi Gene,
> Since I'm running DC Servos I wanted the ability to clamp the back emf
> from a decelerating motor.  I built a small circuit that sensed both
> high voltage and AC power.   It puts a resistor across the DC rail to
> pull it down and the resistor is connected with both a relay and a FET
> in parallel.
>
> When power vanishes the relay is de-energized and the 105VDC power
> supply is quickly drained through the NC connection on the relay.  The
> FET does the same but at high speeds to avoid that over voltage
> condition.
>
> Since the little PIC processor senses AC voltage it can also run a
> relay on a second small board that switches across an inrush resistor.
>  The advantage over a high power thermistor is no heat and you can
> cycle power without worrying about the inrush thermistor still being
> way too hot and therefore too low a resistance.
>
> Schematics attached.
>
Both would seem to be more complex than a few lines of hal code I can 
easily write. The only time energy recovery is/is not a problem is 
during a full song reverse, where the full 4 quadrant pwm-servo runs my 
126 volt supply up to about 170 volts by the time it has bought that big 
motor to a full stop, which is well above the 65V x 2 of the filter 
caps, but its used up respinning the motor in the other direction in 
another 200ms, so cap heating from the caps leakage is not a problem.  
Essentially the same condition exists for TLM's reversal since It also 
uses Jon's pwm-servo, but there the caps are rated at 150 working, 175 
surge, and the surge is of such short duration its a never mind.  With a 
5" chuck for inertia to reverse, its obviously longer, around a second, 
but I don't tap at more than 200 revs anyway. More revs=more overshoot, 
hard to guess so I don't.
 
> John Dammeyer
>
> > -Original Message-
> > From: Gene Heskett [mailto:ghesk...@shentel.net]
> > Sent: May-19-20 10:49 AM
> > To: Enhanced Machine Controller (EMC)
> > Subject: [Emc-users] hypothetical, maybe not, switching psu question
> >
> > Greetings all;
> >
> > Having destroyed one 40 amp SSR by turning on the switching psu;s
> > for the two running the X motors and the builtin supply of the
> > even bigger drive running the Z axis, already, I am now
> > contemplating how to do a soft start to limit the initial in-rush of
> > charging up those 3 power supplies.
> >
> > And doing it in a lower powered version of how I am doing the huge
> > analog supply that runs the spindle motor.
> >
> > There, I have two timers which are controlling two 40 amp SSR's with
> > a 50 ohm 200 watt resistor, so it starts charging that supply with
> > its thousands of u-f's by applying the power thru that big resistor,
> > then the 2nd SSR comes on applying it directly 3 seconds later. 
> > This has worked flawlessly for about 4 years now.
> >
> > Now I have obtained two more used genuine crydom 40 amp 480 volt
> > SSR's, and am considering doing the same thing in essence, only with
> > a much smaller ohmage R to limit the in-rush this batch of switchers
> > in a similar manner.
> >
> > But switchers, I have heard, need that initial bump to get started
> > correctly. To that end I've also ordered a pair of 10 ohm 70 watt
> > resistors, which if need be can be paralleled for 5 ohms in series
> > with these supplies for the first 1/2 to 1 second.
> >
> > But I intend to use one of these in another analog supply, starting
> > the spindle psu in The Little Monster too, putting all its heavy
> > power under LCNC's control.  But that is a different project.
> >
> > These switchers are, or s/b all fused to protect them in the event
> > they don't start.  So I don't expect a start failure to do more than
> > blow the fuse.
> >
> > Has anyone else any experience with this, that can add gotcha's to
> > watch for in such a current limited startup?  10 ohms in series with
> > the power to protect the SSR's is the basic idea. 10 ohms would
> > limit at 12.5 amps of in-rush, which seems reasonable.
> >
> > Thanks all.
> >
> > 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)
> > If we desire respect for the law, we must first make the law
> > respectable. - Louis D. Brandeis
> > Genes Web page 
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users


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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list

Re: [Emc-users] SPAM: hypothetical, maybe not, switching psu question

[Todd Zuercher]

Are  you sure your 40 amp SSR was what it claimed it was.   I recall someone on 
this list telling a story about how he opened up some inexpensive SSRs to find 
woefully under spec-ed internal components (like 1/4th the units rated 
capacity).

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Gene Heskett  
Sent: Tuesday, May 19, 2020 1:49 PM
To: Enhanced Machine Controller (EMC) 
Subject: SPAM: [Emc-users] hypothetical, maybe not, switching psu question

[EXTERNAL EMAIL] Be sure links are safe.

Greetings all;

Having destroyed one 40 amp SSR by turning on the switching psu;s for the two 
running the X motors and the builtin supply of the even bigger drive running 
the Z axis, already, I am now contemplating how to do a soft start to limit the 
initial in-rush of charging up those 3 power supplies.

And doing it in a lower powered version of how I am doing the huge analog 
supply that runs the spindle motor.

There, I have two timers which are controlling two 40 amp SSR's with a 50 ohm 
200 watt resistor, so it starts charging that supply with its thousands of 
u-f's by applying the power thru that big resistor, then the 2nd SSR comes on 
applying it directly 3 seconds later.  This has worked flawlessly for about 4 
years now.

Now I have obtained two more used genuine crydom 40 amp 480 volt SSR's, and am 
considering doing the same thing in essence, only with a much smaller ohmage R 
to limit the in-rush this batch of switchers in a similar manner.

But switchers, I have heard, need that initial bump to get started correctly. 
To that end I've also ordered a pair of 10 ohm 70 watt resistors, which if need 
be can be paralleled for 5 ohms in series with these supplies for the first 1/2 
to 1 second.

But I intend to use one of these in another analog supply, starting the spindle 
psu in The Little Monster too, putting all its heavy power under LCNC's 
control.  But that is a different project.

These switchers are, or s/b all fused to protect them in the event they don't 
start.  So I don't expect a start failure to do more than blow the fuse.

Has anyone else any experience with this, that can add gotcha's to watch for in 
such a current limited startup?  10 ohms in series with the power to protect 
the SSR's is the basic idea. 10 ohms would limit at 12.5 amps of in-rush, which 
seems reasonable.

Thanks all.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] hypothetical, maybe not, switching psu question

[Gene Heskett]

On Tuesday 19 May 2020 14:39:28 Chris Albertson wrote:

> The usual method to limit inrush that is used in almost all
> electronic devices is to place an NTC thermistor in series with the AC
> mains supply.  If you take apart any TV, stereo amp, or PC power
> supply that was built this century you find them inside.
>
> They are really easy to use.  They act just like a resister and
> limt current just like a resistor but the resistance changes with
> time. When you first hit the "on" switch the thermistor might have a
> resistance of 100 Ohms, then after a second it falls to about 2 ohms. 
>  Ametherm is a major manufacturer of these and will give anyone a
> handful of samples and there is a ton of information on their web site
> about how to select and use these devices.

> https://www.ametherm.com

I'll do some reading. The first schematic shown there basically uses one 
of those in place of my fixed R, but the 2nd SSR still shorts it, 
exactly as my timers do.  So it is not an obvious cost saver.

> The trick to using these is to match their specs to your needs.  Yu
> need to use one that has the correct resistances, and time constant. 
> It is like building an RC lowpass filter.
>
> Yes, you could simulate a thermistor with some switches, a timer, and
> load resisters or just ask Ametherm and they give you a dozen samples.
>
> There is a technical article on the above web site that is titled
> "limiting in-rush current in DC motors".   They work out a problem
> where you place an NTC Thermister in series with a large DC motor.  In
> this case the resistence starts at about 1 Ohm and falls to about 0.01
> Ohms when the motor is running full speed.
>
> With motors they place them in series with the motor.  In a power supy
> they place them in series with the AC mains or in series with the
> transformers winding that has the most current.
>
> The best thing is that these things are so simple that the can't fail
> and they are way-cheap.
>
This might be true, but the truth is that they are also one of the more 
troubling failures in home electronics/  They are not new by any means, 
so my history with them goes back about 40 years. The failure is 
generally that the NTC fades over time, until they either start a fire, 
or simply turn the center section into ash which is so weak the 
connections at their soldered joints pulls them open.  And they do it 
with no drama until the customer brings it to me saying it doesn't turn 
on anymore. Finding the one with suitable characteristics can be fun too 
because the maker usually flat lies about the actual power drain.  So 
you put in the recommended one, but the tubes are tired so it workls but 
doesn't draw the target power, causing the device to run cold and 
temporarily at a higher resistance, further hurting the performance.

My cobbled up timers and SSR circuitry may cost 50x the price one of 
those, but so far the failure rate has been zero.  But doing that softer 
start to a switcher makes me ask for other peoples experience since I 
have only relatively ancient history to go by.

> On Tue, May 19, 2020 at 10:51 AM Gene Heskett  
wrote:
> > Greetings all;
> >
> > Having destroyed one 40 amp SSR by turning on the switching psu;s
> > for the two running the X motors and the builtin supply of the
> > even bigger drive running the Z axis, already, I am now
> > contemplating how to do a soft start to limit the initial in-rush of
> > charging up those 3 power supplies.
> >
> > And doing it in a lower powered version of how I am doing the huge
> > analog supply that runs the spindle motor.
> >
> > There, I have two timers which are controlling two 40 amp SSR's with
> > a 50 ohm 200 watt resistor, so it starts charging that supply with
> > its thousands of u-f's by applying the power thru that big resistor,
> > then the 2nd SSR comes on applying it directly 3 seconds later. 
> > This has worked flawlessly for about 4 years now.
> >
> > Now I have obtained two more used genuine crydom 40 amp 480 volt
> > SSR's, and am considering doing the same thing in essence, only with
> > a much smaller ohmage R to limit the in-rush this batch of switchers
> > in a similar manner.
> >
> > But switchers, I have heard, need that initial bump to get started
> > correctly. To that end I've also ordered a pair of 10 ohm 70 watt
> > resistors, which if need be can be paralleled for 5 ohms in series
> > with these supplies for the first 1/2 to 1 second.

The heating pulse in the R during the turn on is significant, but very 
short in duration.  That is why the relatively large mass of the R.
 
> >
> > But I intend to use one of these in another analog supply, starting
> > the spindle psu in The Little Monster too, putting all its heavy
> > power under LCNC's control.  But that is a different project.
> >
> > These switchers are, or s/b all fused to protect them in the event
> > they don't start.  So I don't expect a start failure to do more than
> > blow the fuse.
> >
> > Has anyone 

Re: [Emc-users] Triggering an external relay from a BOB

[Dan Henderson]

Update for everyone. I now have two working relays controlling the
operation of the spindle motor via BOB and Parallel Port. I've also now
successfully tested the G33.1 Rigid Tapping cycle with this setup.

Relay #1 is used to power on/off the motor controller board (MC2100). (M5
or S0 triggers off, M3 or M4 triggers on)
Relay #2 is used to reverse the polarity of the spindle motor providing CCW
operation. (M4 Triggers on, M3 or M5 triggers off)

In order to get these functioning properly, I had to implement two
different "timerdelay" functions in HAL.
One delay is needed to allow the MC2100 board to power on and initialize
before PWM signals are sent.

The second delay is needed to slow down the reverse polarity relay in order
to ensure the motor controller is properly powered off before allowing the
relay to flip back to normal polarity. Otherwise the spindle would flip
rotation to cw once triggered.

HAL may not be the easiest to understand, but it can do some amazing work
if you figure it out!

Thanks for all the help on this thread!

Dan



On Fri, May 15, 2020 at 8:10 PM Dan Henderson  wrote:

> Great idea Andy!
>
> On Fri, May 15, 2020 at 6:02 PM andy pugh  wrote:
>
>> On Fri, 15 May 2020 at 18:40, Dan Henderson  wrote:
>>
>> > One BOB requires an external 5v supply the other is able to use a USB
>> port
>> > from the PC for power.
>>
>> You might be able to steal 5V from the second for the first.
>>
>> --
>> 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
>>
>>
>> ___
>> Emc-users mailing list
>> Emc-users@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/emc-users
>>
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] hypothetical, maybe not, switching psu question

[John Dammeyer]

Hi Gene,
Since I'm running DC Servos I wanted the ability to clamp the back emf from a 
decelerating motor.  I built a small circuit that sensed both high voltage and 
AC power.   It puts a resistor across the DC rail to pull it down and the 
resistor is connected with both a relay and a FET in parallel.  

When power vanishes the relay is de-energized and the 105VDC power supply is 
quickly drained through the NC connection on the relay.  The FET does the same 
but at high speeds to avoid that over voltage condition.  

Since the little PIC processor senses AC voltage it can also run a relay on a 
second small board that switches across an inrush resistor.  The advantage over 
a high power thermistor is no heat and you can cycle power without worrying 
about the inrush thermistor still being way too hot and therefore too low a 
resistance.

Schematics attached.

John Dammeyer


> -Original Message-
> From: Gene Heskett [mailto:ghesk...@shentel.net]
> Sent: May-19-20 10:49 AM
> To: Enhanced Machine Controller (EMC)
> Subject: [Emc-users] hypothetical, maybe not, switching psu question
> 
> Greetings all;
> 
> Having destroyed one 40 amp SSR by turning on the switching psu;s for the
> two running the X motors and the builtin supply of the even bigger
> drive running the Z axis, already, I am now contemplating how to do a
> soft start to limit the initial in-rush of charging up those 3 power
> supplies.
> 
> And doing it in a lower powered version of how I am doing the huge analog
> supply that runs the spindle motor.
> 
> There, I have two timers which are controlling two 40 amp SSR's with a 50
> ohm 200 watt resistor, so it starts charging that supply with its
> thousands of u-f's by applying the power thru that big resistor, then
> the 2nd SSR comes on applying it directly 3 seconds later.  This has
> worked flawlessly for about 4 years now.
> 
> Now I have obtained two more used genuine crydom 40 amp 480 volt SSR's,
> and am considering doing the same thing in essence, only with a much
> smaller ohmage R to limit the in-rush this batch of switchers in a
> similar manner.
> 
> But switchers, I have heard, need that initial bump to get started
> correctly. To that end I've also ordered a pair of 10 ohm 70 watt
> resistors, which if need be can be paralleled for 5 ohms in series with
> these supplies for the first 1/2 to 1 second.
> 
> But I intend to use one of these in another analog supply, starting the
> spindle psu in The Little Monster too, putting all its heavy power under
> LCNC's control.  But that is a different project.
> 
> These switchers are, or s/b all fused to protect them in the event they
> don't start.  So I don't expect a start failure to do more than blow the
> fuse.
> 
> Has anyone else any experience with this, that can add gotcha's to watch
> for in such a current limited startup?  10 ohms in series with the power
> to protect the SSR's is the basic idea. 10 ohms would limit at 12.5 amps
> of in-rush, which seems reasonable.
> 
> Thanks all.
> 
> 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)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
> 
> 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


SoftStart1.10.pdf
Description: Adobe PDF document


DrainControl1.20.pdf
Description: Adobe PDF document
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] hypothetical, maybe not, switching psu question

[Chris Albertson]

The usual method to limit inrush that is used in almost all
electronic devices is to place an NTC thermistor in series with the AC
mains supply.  If you take apart any TV, stereo amp, or PC power supply
that was built this century you find them inside.

They are really easy to use.  They act just like a resister and
limt current just like a resistor but the resistance changes with time.
When you first hit the "on" switch the thermistor might have a resistance
of 100 Ohms, then after a second it falls to about 2 ohms.   Ametherm is a
major manufacturer of these and will give anyone a handful of samples and
there is a ton of information on their web site about how to select and use
these devices.
https://www.ametherm.com
The trick to using these is to match their specs to your needs.  Yu need to
use one that has the correct resistances, and time constant.  It is like
building an RC lowpass filter.

Yes, you could simulate a thermistor with some switches, a timer, and load
resisters or just ask Ametherm and they give you a dozen samples.

There is a technical article on the above web site that is titled "limiting
in-rush current in DC motors".   They work out a problem where you place an
NTC Thermister in series with a large DC motor.  In this case the
resistence starts at about 1 Ohm and falls to about 0.01 Ohms when the
motor is running full speed.

With motors they place them in series with the motor.  In a power supy they
place them in series with the AC mains or in series with the transformers
winding that has the most current.

The best thing is that these things are so simple that the can't fail and
they are way-cheap.





On Tue, May 19, 2020 at 10:51 AM Gene Heskett  wrote:

> Greetings all;
>
> Having destroyed one 40 amp SSR by turning on the switching psu;s for the
> two running the X motors and the builtin supply of the even bigger
> drive running the Z axis, already, I am now contemplating how to do a
> soft start to limit the initial in-rush of charging up those 3 power
> supplies.
>
> And doing it in a lower powered version of how I am doing the huge analog
> supply that runs the spindle motor.
>
> There, I have two timers which are controlling two 40 amp SSR's with a 50
> ohm 200 watt resistor, so it starts charging that supply with its
> thousands of u-f's by applying the power thru that big resistor, then
> the 2nd SSR comes on applying it directly 3 seconds later.  This has
> worked flawlessly for about 4 years now.
>
> Now I have obtained two more used genuine crydom 40 amp 480 volt SSR's,
> and am considering doing the same thing in essence, only with a much
> smaller ohmage R to limit the in-rush this batch of switchers in a
> similar manner.
>
> But switchers, I have heard, need that initial bump to get started
> correctly. To that end I've also ordered a pair of 10 ohm 70 watt
> resistors, which if need be can be paralleled for 5 ohms in series with
> these supplies for the first 1/2 to 1 second.
>
> But I intend to use one of these in another analog supply, starting the
> spindle psu in The Little Monster too, putting all its heavy power under
> LCNC's control.  But that is a different project.
>
> These switchers are, or s/b all fused to protect them in the event they
> don't start.  So I don't expect a start failure to do more than blow the
> fuse.
>
> Has anyone else any experience with this, that can add gotcha's to watch
> for in such a current limited startup?  10 ohms in series with the power
> to protect the SSR's is the basic idea. 10 ohms would limit at 12.5 amps
> of in-rush, which seems reasonable.
>
> Thanks all.
>
> 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)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>


-- 

Chris Albertson
Redondo Beach, California

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] hypothetical, maybe not, switching psu question

[Gene Heskett]

Greetings all;

Having destroyed one 40 amp SSR by turning on the switching psu;s for the 
two running the X motors and the builtin supply of the even bigger 
drive running the Z axis, already, I am now contemplating how to do a 
soft start to limit the initial in-rush of charging up those 3 power 
supplies.

And doing it in a lower powered version of how I am doing the huge analog 
supply that runs the spindle motor.

There, I have two timers which are controlling two 40 amp SSR's with a 50 
ohm 200 watt resistor, so it starts charging that supply with its 
thousands of u-f's by applying the power thru that big resistor, then 
the 2nd SSR comes on applying it directly 3 seconds later.  This has 
worked flawlessly for about 4 years now.

Now I have obtained two more used genuine crydom 40 amp 480 volt SSR's, 
and am considering doing the same thing in essence, only with a much 
smaller ohmage R to limit the in-rush this batch of switchers in a 
similar manner.

But switchers, I have heard, need that initial bump to get started 
correctly. To that end I've also ordered a pair of 10 ohm 70 watt 
resistors, which if need be can be paralleled for 5 ohms in series with 
these supplies for the first 1/2 to 1 second.

But I intend to use one of these in another analog supply, starting the 
spindle psu in The Little Monster too, putting all its heavy power under 
LCNC's control.  But that is a different project.

These switchers are, or s/b all fused to protect them in the event they 
don't start.  So I don't expect a start failure to do more than blow the 
fuse.

Has anyone else any experience with this, that can add gotcha's to watch 
for in such a current limited startup?  10 ohms in series with the power 
to protect the SSR's is the basic idea. 10 ohms would limit at 12.5 amps 
of in-rush, which seems reasonable.

Thanks all.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] timestamp ethernet hardware

[Jon Elson]

On 05/18/2020 10:40 PM, Thomas J Powderly wrote:

I think timestamping was a benefit, esp for PPMC.

Some PPMC devices can use time stamps to estimate encoder 
velocity. I don't think that has anything to

do with Ethernet packets.

Jon


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users