Duet Wifi SSR wiring for 'soft on' button.

What I'm trying to achieve is an SSR to turn the duet off after a print using M81. I probably won't be supplying a 5v to the board, so as a work around I have a momentary switch at the front of the printer that allows the live to connect long enough to power the board and run M80 command.

My main worries are:

1) Have I got the wiring right? I'm following this guide: http://doc.3dmodularsystems.com/ps_on-kit-assembly/, but if I'm correct the duet does not supply 5v via the PS_on next to the VIN connectors, this is instead 5v in. Does this mean I have to run 5v from the first pin on the expansion pins, and then run ground from PS_on to the relay?

2) SSR's leak residual power and this can charge up diodes / capacitors over time to make the machine appear like its on. Is this a risk? Can this happen with a 24v supply + duet wifi? Safety is my concern here and I'd hate for someone to think the machine is off or safe to use.

3) With the above in mind, if it is an issue, does anyone have any recommendations for mechanical relays? When they fail, they turn the load off by default and cannot leak residual charge. Am i over thinking this? The relay will only be used to turn the power supply on before setting up a print, and off after printing

Edited 1 time(s). Last edit at 03/11/2018 08:57AM by Origamib.

1. Connect the negative SSR control terminal to PS_ON, and the positive control terminal to either +5V or +3.3V from the expansion connector.

2. I've never heard of an SSR leaking enough to start the sorts of power supplies used to power 3D printers. If it did, then the symptom would be that the power supply runs in very short bursts at regular intervals. A remedy would be to put a light resistive load in parallel with the mains input terminals of the PSU. Something like a 120K 0.5W resistor with an appropriate voltage rating.

Edited 1 time(s). Last edit at 03/11/2018 08:00PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
1. Connect the negative SSR control terminal to PS_ON, and the positive control terminal to either +5V or +3.3V from the expansion connector.

2. I've never heard of an SSR leaking enough to start the sorts of power supplies used to power 3D printers. If it did, then the symptom would be that the power supply runs in very short bursts at regular intervals. A remedy would be to put a light resistive load in parallel with the mains input terminals of the PSU. Something like a 120K 0.5W resistor with an appropriate voltage rating.

Thanks for your reply. Just as I thought to be honest but thought I'd check for peace of mind. I have not heard of an SSR starting up a power supply, but it's not something I'd like to happen either.

Edited 1 time(s). Last edit at 03/12/2018 09:43AM by Origamib.

I think I understand, but can someone provide a diagram so I don't blow anything up, especially my brand new Duet Wifi?

I don't have a diagram to hand, but some have been published on the forum at duet3d.com.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
Connect the negative SSR control terminal to PS_ON, and the positive control terminal to either +5V or +3.3V from the expansion connector.

Actually, since the SSR control voltage says 3-32, I could just tap into the 24v I am supplying to the Duet, right (instead of the 5 or 3.3)?

If you wire it like that then the Duet won't be able to turn the power off. Wiring it to PS_ON lets the Duet turn it off.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I just finished wiring my Duet, and at first glance it looks like PS_ON is not going low to keep the SSR set. As soon as I release the switch that connects the load side of the SSR, the power goes off.

with the Duet turned on (holding the switch) , if I check the voltage between the 5v pin on the expansion connector and ground, it is 5 volts. If I check between the same 5v pin and PS_ON, it is zero.

Is there something I need to do to enable the PS_ON pin?

I just tried M80 from the console and that seems to work.

I'll try adding it to config.g