How to power the Mini5P from external 5V (no SBC)?
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I am looking at the Mini5P wiring page to understand how to run it on external 5V (no SBC). At one point it says "see the "Powering the board, 5V supply" section below for more information" but I can't find that section. Anybody knows where it is.
https://duet3d.dozuki.com/Wiki/Duet_3_Mini_5plus_Wiring
My understanding is that I can connect 5V at the Ext 5V connector, short the jumber 5V Com / 5V Ext In, and do something with the Internal 5V Disable jumper but would like to be sure about the details before I fry something.
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@zapta use this header to input 5v
and set this header
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@jay_s_uk, thanks for the quick response. There is a third jumper called "Internal 5V Disable". How should it be configured?
I expect to have external 5V all the time and 24V only when PS_ON enables it.
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@zapta said in How to power the Mini5P from external 5V (no SBC)?:
There is a third jumper called "Internal 5V Disable". How should it be configured?
good spot, so there is. remove the jumper
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Hi @jay_s_uk, I wonder if I should to enable the internal 5V (jumper opened) or disable it (jumper shorted).
If enabled, even if the external 5V is turned off, the system will keep from the 24V which may be counter intuitive (?). Also, IIRC, on the Duet 2 Wifi, the 5V DC/DC was the hotest spot on the PCB.
Is the general recommendation to leave the internal 5V enabled?
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@zapta yes, sorry. add a jumper to it as well
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@jay_s_uk, thanks!
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@zapta too early in the morning and my brain isn't fully in gear!
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@zapta said in How to power the Mini5P from external 5V (no SBC)?:
At one point it says "see the "Powering the board, 5V supply" section below for more information" but I can't find that section.
Sorry, that should link to https://duet3d.dozuki.com/Wiki/Duet_3_Mini_5plus_Hardware_overview#Section_5V_Power_Options on the Hardware page. Copy/paste error, will fix.
Fixed. Also changed Hardware page to recommend disabling internal 5V regulator:
5V_EXT_INPUT: With the 5V_SELECT jumper set to this position, 5V is passed through to both 5V_EXT and 5V_INT from the EXT_5V header. When using EXT_5V, add jumper to Int_5V_Disable, to disable the onboard 5V regulator. The EXT_5V header also has a pin for controlling an external power supply (note signal shared with io4.out). This allows for the board to be powered from 5V, with an external supply for VIN turned on and off as required.
Ian
TronXY X5S with Duet 3 MB6HC and Roto toolboard : Cartesian bed-slinger with Duet 3 Mini 5+ WiFi and 1LC : RRP Fisher Delta v1 with Duet 2 Maestro : Polargraph with Duet 2 WiFi
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Thanks @droftarts.
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Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6
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@fcwilt, my goal is having the duet being able to shut off power in emergency to heaters and motors while still staying alive so I can see its status.
I plan to achieve it using a electromechanical relay that is controlled by ps_on and feeds the 110VAC to the 24VDC power supply and the 110VAC heatbed's SSR.
For 5V I plan to use Mean Well RS-25-5 which is small and fanless.
Any reason not to go with this plan?
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@fcwilt, that's the plan. (Relay flyback diode not shown).
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@zapta said in How to power the Mini5P from external 5V (no SBC)?:
@fcwilt, my goal is having the duet being able to shut off power in emergency to heaters and motors while still staying alive so I can see its status.
I plan to achieve it using a electromechanical relay that is controlled by ps_on and feeds the 110VAC to the 24VDC power supply and the 110VAC heatbed's SSR.
For 5V I plan to use Mean Well RS-25-5 which is small and fanless.
Any reason not to go with this plan?
What sort of emergencies do you anticipate?
In the years I have been building and using 3D printers I have never encountered a need for this sort of setup.
Frederick
Printers: a small Utilmaker style, a small CoreXY and a E3D MS/TC setup. Various hotends. Using Duet 3 hardware running 3.4.6
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@zapta I do this on my Duet WiFi and plan to when I get round to building my next printer (toolchanger with a D3Mini + expansions).
Two things to be aware of. If you use expansion boards, they won't be powered until you turn on the 24v supply, so have to be reconfigured after. I guess you can just turn on the relay from config though, or do a macro that turns it on and configures the expansion boards.
Other thing is inrush currents from DC PSUs which can be several times the normal peak current. I welded my first relay shut with the inrush current after a few cycles when first setting up my printer. That was a cheap 10A relay. Now I use a pair of 30A relays on both the HV and LV side of the PSU and not had any problems
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@fcwilt said in How to power the Mini5P from external 5V (no SBC)?:
What sort of emergencies do you anticipate?
Mostly a heater power mosfet/ssr becoming permanently short.
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@zapta said in How to power the Mini5P from external 5V (no SBC)?:
@fcwilt said in How to power the Mini5P from external 5V (no SBC)?:
What sort of emergencies do you anticipate?
Mostly a heater power mosfet/ssr becoming permanently short.
I'm not sure what you can learn from the firmware if a device like that fails.
Perhaps install thermal cutouts on the heat generating devices which will protect you from any source of too much heat, not just device failures.
Frederick
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@fcwilt said in How to power the Mini5P from external 5V (no SBC)?:
I'm not sure what you can learn from the firmware if a device like that fails.
If it happens during printing, the firmware detects it (abnormal PID behavior) and shuts off PS ON. I have a similar setting in my current printer (HEVO) and I confirmed that it works.
I also have thermal fuse on the bed but not on the nozzle heater.
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@zapta said in How to power the Mini5P from external 5V (no SBC)?:
@fcwilt said in How to power the Mini5P from external 5V (no SBC)?:
I'm not sure what you can learn from the firmware if a device like that fails.
If it happens during printing, the firmware detects it (abnormal PID behavior) and shuts off PS ON. I have a similar setting in my current printer (HEVO) and I confirmed that it works.
I also have thermal fuse on the bed but not on the nozzle heater.
I know it does that but the firmware doesn't know the reason.
As long as you are happy with the result that is all that matters.
Frederick
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@fcwilt you're right you don't know the 'reason' but you at least know which heater it is, and can maybe see the temperature graph
