Meanwell HRP-600-24 PSU on/off??
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Well how is everyone doing this evening?
I got my grubby little hands on a new Meanwell HRP-600-24 power supply for a new printer design I am working on.
I just noticed that this power supply should have an on/off function like an ATX supply I believe. It has a connector labeled GND/DC-OK/S-/S+. How would this be wired to say a momentary push button like a desktop case has?I think it would be a neat function to incorporate into the front panel of my frames enclosure alongside the PanelDue.
Ideally I would like the push button for turning the power on and off (main priority) it would also be nice to retain the "M" code setup for having the Duet turn itself off after a print once temperatures reach "x", but, I don't know if this would work alongside having the power on/off button. This is new to me since the meanwell PSU I normally use is the SE series and I just have the plugins with integrated rocker switches on the back of all my other printers/cnc/lasers.
Here is a link to meanwells site/manual for the PSU
http://www.meanwell.com/productPdf.aspx?i=471
THANKS!
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I don't see any indication in the data sheet that those PSUs have a remote on/off facility.
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I think the HRPG-600 (not the HRP-600) has the remote on/off. However, I don't think it will work easily with the duet3d.
I remember looking into MW's remote on/off functionality at some time in the past, and I found that it wasn't "ATX compatible." ATX (and duet3d) signals power on by grounding a 5VDC standby (closed circuit == power ON.)
In contrast, the meanwell system works by shorting two contacts to turn power OFF and opening that circuit to turn power ON.
This can be seen on the 3rd page of the HRPG-450 series specification here: https://www.mouser.com/ds/2/260/r1549_3-1109569.pdf
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Looks like the Meanwell system is like ATX power but in reverse. I guess it would be possible to have an M-code to reverse the sense of PS_ON.
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The S+/S- lines are for remote sensing that allows the supply to compensate for voltage loss over the lines. DC OK is a signal to let something know the supply is on and working.
The descriptions below are from the HRPG-450 manual since they don't seem to appear in the HRP-600 or SE-600 manuals, DC OK may have a different implementation on the HRP but the S+/S- should be the same on HRPH, HRP, and SE supplies.
S+ = Positive sensing. The +S signal should be connected to the positive terminal of the load. The +S and -S leads should be twisted in pair to minimize noise pick-up effect. The maximum line drop compensation is 0.5V.
S- = Negative sensing. The -S signal should be connected to the negative terminal of the load. The -S and +S leads should be twisted in pair to minimize noise pick-up effect. The maximum line drop compensation is 0.5V.
DC OK - DC-OK signal is a TTL level signal. High when PSU turns on.
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Looks like the Meanwell system is like ATX power but in reverse. I guess it would be possible to have an M-code to reverse the sense of PS_ON.
I don't know if that would work… (Or perhaps it'd be better if I said that I'd be paranoid about it.)
With ATX, the PS_ON pin is grounded to a common ground. The point here is that there doesn't seem to be specific ground contact for the PS_ON pin.
With the MW, it's closing/opening a specific set of pins (usually labeled RC+ and RC-) but nothing states that RC- is a common ground or if it's safe to tie RC- to the PSU's common ground. It's "probably" okay, but I'd be paranoid about doing it when RC- is a specific pin and the specs don't just state something like "short RC+ to GND to power OFF."
Adding to the annoyance is that the auxiliary power (similar to ATX 5VDC standby) on those MW PSU's is limited to 0.3 amps (1.5W) which is less than the 2W suggested to power only the duet3d board. That means that the 5VDC power for the duet3d board (so that you can send the M80 command to begin with) will have to come from a secondary source such as USB, and that introduces multiple grounds...
It seems like a lot of headaches, and being that a secondary 5VDC source needs to be put on the system anyway, a person might be a lot better off getting a less expensive MW PSU (without the remote control and auxiliary functions) and just use a simple relay for ATX-like on/off. (A mechanical relay should work fine for this.)
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Well I would most definitely take the route of paranoia in this case then. I will stick with using a simple switch on/off like I've always done. Now I just have to find some sort of push button style switch I can use to toggle the mains (120v) going to the power supply.
I'd really like to run a switch like this on this machine (a side note, machine is supposed to be a showpiece machine as well as new main workhorse that I can showcase to customers rather then show them the army of open frame extrusion based printers. So a sleek setup is desired)
https://www.amazon.com/gp/product/B06XRFCSGC/ref=ox_sc_act_title_1?smid=A1THAZDOWP300U&psc=1Also looking to add a manual reset/EM stop button on front control panel of machine.
Also does Duet support a physical "feed hold" button for 3d printing. This is a random idea that popped into my head as I was typing while staring at my minimill.
edited for additional info -
Wouldn't feed hold be equivalent to using pause/resume with empty pause.g and resume.g files? That wouldn't be desirable when 3D printing because you would get a blob or worse.
