External Relay with PS_ON - Which line to switch?
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I am facing same dilemma. Got this relay https://www.amazon.com/gp/product/B0117FB276 and plan to use it to switch the +24V to the two heaters. Duet will be powered all the time by 24V. Haven't tried it yet.
Will consider later to add a +5V PS and cut the the +24V Vin to the duet to reenergize also steppers and fans. Not sure if this is necessary though.
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It really depends on how "safe" you want to be. If you switch the mains feeds to the power supplies then there could be some delay between the input going off and the 24V dropping since the capacitors will keep the 24v going for a second or two. On the other hand, if you leave the power supplies always powered and switch the 24v going to the duet and external mosfet, then you may not be able to turn off the mains quickly in the event of a PSU short, fire, etc.
In practice, I think most folks switch the mains (as I do) since the time between you recognizing an issue and hitting your emergency stop button will probably be longer than the time it takes for moving kinematics to drain the PSU caps.
You only need to switch the line/hot wire to the PSUs and an SSR might be better than a relay. SSRs when they fail, they usually fail cosed but as you've discovered overloaded relays will also fuse closed.
You can control the SSR or relay from the PSU_ON pin on the duet and you can also wire your emergency stop button (if it's normally closed) in series with that line so the button will trigger the SSR/relay as well as the PSU_ON signal.
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Thanks for your input @gtj0 & @zapta
I think what I'll do is get one of the 30A electro-mechanical relay modules to switch the 24V side of both power supplies and also get an SSR to cut the live wire going in to them. I'll drive all of them via the Duet's PS_ON. That way I can get the best of both worlds.
My physical E-stop button is already wired to cut the mains supply to both 24VPSUs so I'll keep that separate and up-stream of the SSR. I generally keep that depressed unless printing (and especially will do with this setup) in case I accidentally activate the PS_ON when I didn't mean too. You can see it in DWC too as it reports the input voltage
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@engikeneer, be aware that PS_ON provides protection only during printing. If for example your printer is in idle mode, you set the temp manually from PanelDue and the system has a thermal runaway, e.g. due to a shorten mosfet, duet will detect it but will not disable PS_ON.
(your plans sounds reasonable to me, I don't have a suggestion).
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@zapta It still provides "manual" protection in that you can send M81 via the DWC "ATX Power" buttons or any other means at any time.
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Hi Guys,
@gtj0 , Can I take you back to the following post where you replied regarding adding an addition SSR instead of an opto relay;
https://forum.duet3d.com/topic/6287/5v-supply-using-ps_on-to-enable-24v-and-120v-ssr
I'm new to duet and planning on upgrading my X5sa Pro with my Duet3 I purchased a couple of years ago (moved house and only got the printer running again last month). At the moment I'm considering all my wiring options. I don't have an ATX psu, but similar to a meanwell, so no PS_ON facility
If the the opto relay is replaced with an SSR, how is this wired, as the SSR only has the 2 inputs and 2 outputs and the diagram shows the 5v and Gnd, and the PS_ON signal cable?Just seen you your ‘little’ Black Beauty. Wow, I like that very much. I bet you don't have a wiring diagram!
I'd be grateful for you advice.
Dizzwold.
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@dizzwold said in External Relay with PS_ON - Which line to switch?:
Hi Guys,
@gtj0 , Can I take you back to the following post where you replied regarding adding an addition SSR instead of an opto relay;
https://forum.duet3d.com/topic/6287/5v-supply-using-ps_on-to-enable-24v-and-120v-ssrWhew, gonna need the way-back-time-machine for that one
I'm new to duet and planning on upgrading my X5sa Pro with my Duet3 I purchased a couple of years ago (moved house and only got the printer running again last month).
I moved back in March and still haven't gotten Black Beauty up and running again.
At the moment I'm considering all my wiring options. I don't have an ATX psu, but similar to a meanwell, so no PS_ON facility
That's fine. I don't think anyone actually uses a real ATX power supply. The pin on the Duets are just named that since it serves the same function as the similar pin in ATX power supplies.
If the the opto relay is replaced with an SSR, how is this wired, as the SSR only has the 2 inputs and 2 outputs and the diagram shows the 5v and Gnd, and the PS_ON signal cable?
The PS_ON pin goes to ground when you issue an M80 GCode command and open when you issue an M81. So assuming you're powering the board itself with 5V from USB or other external source, you'd connect the negative control terminal on the SSR to the PS_ON pin and the positive control terminal to any +5V pin on the Duet. The line side of the SSR would be connected just like a switch between your mains power and the PSU so the mains hot wire would go to one load terminal on the SSR, the other load terminal on the SSR to the hot/line terminal on the PSU and the neutral terminal on the PSU to the neutral mains.
With this you can issue M80/M81 to control your 12/24V PSU.
Just seen you your ‘little’ Black Beauty. Wow, I like that very much. I bet you don't have a wiring diagram!
I do have a wiring diagram but it's in my head and unfortunately, I've been experiencing bitrot in those sectors lately.
I'd be grateful for you advice.
Dizzwold.
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@gtj0
Hi gtj0,Thank you for you reply and valued information.
@gtj0 said in External Relay with PS_ON - Which line to switch?:
I moved back in March and still haven't gotten Black Beauty up and running again.
Lol, I moved a year ago today, but being disabled has slowed everything down somewhat.
I was also thinking of adding something like I found here;
https://forum.duet3d.com/topic/6185/switching-psu-on-off
As stated previously, I'm just starting this process so I still have a lot of reading and learning to do, but I'm guessing that the above will also be related to the following config example by armysolo /Duet-PS_ON;
https://github.com/armysolo/Duet-PS_ON
Sorry for all the toing-and froing back and forth with previous threads and examples.I'm currently still using the box-standard Tronxy X5SA Pro 24v heatbed, but do plan on getting a mains powered in the future (like a Keenovo), fitted to a cast aluminium tool plate. I'm also going to use a Raspberry pi and I have a handful of PSU's 5v3a, 12v10a, dual 5v/12v 100w, 24v25a, the original x5sa pro 24v (400w i think), and I'm sure I've got a 36v600w kicking around somewhere, so I spoilt for choice.
I have 2 lots of different SSR's. I have 2 x SSR's (TE Connectivity/Tyco SSR-240D50) and 2 x SSRT's (TE Connectivity/Tyco SSRT-240D10). Would one type be better than the other?
I'm going to have to find some-kind of design software so I can try to start schematically drawing everything up on my mac.
On Black Beauty, am I correct in stating your printhead and part cooling are blown in from outside the printer down a pipe?
Again, I'm very grateful for your time.
Dizz.
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@dizzwold said in External Relay with PS_ON - Which line to switch?:
@gtj0
Hi gtj0,Thank you for you reply and valued information.
@gtj0 said in External Relay with PS_ON - Which line to switch?:
I moved back in March and still haven't gotten Black Beauty up and running again.
Lol, I moved a year ago today, but being disabled has slowed everything down somewhat.
I was also thinking of adding something like I found here;
https://forum.duet3d.com/topic/6185/switching-psu-on-off
As stated previously, I'm just starting this process so I still have a lot of reading and learning to do, but I'm guessing that the above will also be related to the following config example by armysolo /Duet-PS_ON;
https://github.com/armysolo/Duet-PS_ON
Sorry for all the toing-and froing back and forth with previous threads and examples.No worries! The possibilities are endless.
I'm currently still using the box-standard Tronxy X5SA Pro 24v heatbed, but do plan on getting a mains powered in the future (like a Keenovo), fitted to a cast aluminium tool plate. I'm also going to use a Raspberry pi and I have a handful of PSU's 5v3a, 12v10a, dual 5v/12v 100w, 24v25a, the original x5sa pro 24v (400w i think), and I'm sure I've got a 36v600w kicking around somewhere, so I spoilt for choice.
I have 2 lots of different SSR's. I have 2 x SSR's (TE Connectivity/Tyco SSR-240D50) and 2 x SSRT's (TE Connectivity/Tyco SSRT-240D10). Would one type be better than the other?
The SSR-240D50 is a dual SCR unit. SCRs are unidirectional which is why 2 are needed in a single AC SSR. The SSRT-240D10 is a Triac based device which is natively bidirectional so only 1 is needed in an AC SSR. You'd think that'd make the Triac version "better" than the SCR version but the SCRs can handle much higher current than the Triac. I'm not enough of an expert to say which is better assuming both can handle the current you expect to pull with plenty of headroom.
I'm going to have to find some-kind of design software so I can try to start schematically drawing everything up on my mac.
On Black Beauty, am I correct in stating your printhead and part cooling are blown in from outside the printer down a pipe?
Correct. There are 2 blower type fans mounted to the back of the frame and the air travels through 2 flexible Tygon tubes to the tool mount. With all the pictures I have of Black Beauty you'd think I'd have some of the fans, but no. I had to take them off to get BB through my new front door so I can't get any at the moment.
Again, I'm very grateful for your time.
Your welcome!
Dizz.
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With the SSR-240D50, I'm a little confused. So is this not an SSR?
Is there 2 of these SCR's with-in the one device that make it an SSR, or would I need two of these units to make them work like an SSR?
Dizz.
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@dizzwold said in External Relay with PS_ON - Which line to switch?:
With the SSR-240D50, I'm a little confused. So is this not an SSR?
Is there 2 of these SCR's with-in the one device that make it an SSR, or would I need two of these units to make them work like an SSR?
Dizz.
Oops, sorry I should have been clearer... There are two different types of Solid State Relays...
Silicon Controlled Rectifier (SCR) and Triode for Alternating Current (Triac).
SCRs can only pass current in one direction which makes them great for DC switching but not so much for AC switching but they can handle more current than Triacs. Triacs, as the name implies, were designed to handle AC switching which makes them great for switching AC loads but they can't handle the same current as SCRs. So, to get the best of both worlds, manufacturers create SSRs with 2 SCRs hooked up in "inverse parallel". One handles the AC current flow in one direction and the other handles the current in the other direction.
The SSR-240D50 has 2 SCRs in it and the SSRT-240D10 has 1 Triac in it. Functionally they are exactly the same but the current ratings are different.
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Just found this and thought it might be handy for future use considering the wiring.
If you click the link at the top to open in a browser window, then save, download. Then you can play with it.
https://jubilee3d.com/index.php?title=Duet3_Frame_Wiring_DiagramsDizz.
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@dizzwold Good find!
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@gtj0 Hi,
Going back to the diagram above and swapping out the opto relay for an SSR.
On the control side of it you would have the 5v on one terminal of the SSR, and you would have the PS_ON on the other terminal. Would you also have the Ground wire from the duet to the SSR (the same terminal as the PS_ON), or would you just omit the ground wire?
Dizzwold.
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@gtj0
This is what I'm trying to describe above. Would this edited diagram work?
Or does the -Negative from the 5v PSU only go to the EXT 5V and not 'also' to the SSR?
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@dizzwold That's gonna require a bit of studying.
I'll get to it later today.
