Using 12Vdc fans with 24Vdc powered board

A Former User

Good morning, I use a 24VDC powered Duet 2WiFi, and I've broken two cooling fans moving the printer. I already have the same size fans in my house but 12VDC intead of 24VDC, is there a way to us 12VDC fans intead of 24VDC fans without using stepdowns? The heating cartridge can keep on working at 24VDC

Thanks
Andrea

jay_s_uk

@thedragonlord theres no onboard 12v supply on the duet 2 so you'll need to use a stepdown

A Former User

@jay_s_uk said in Using 12Vdc fans with 24Vdc powered board:

@thedragonlord theres no onboard 12v supply on the duet 2 so you'll need to use a stepdown

ok, thanks

pro3d

This post is deleted!

pro3d

@thedragonlord

You can use 2 x 12V fans in series though. The PWM out pins dont like stepdowns I hear. Not sure though

jay_s_uk

@pro3d i use stepdowns quite happily

cosmowave

@pro3d I also use a stepdown without problems...

Norder

@thedragonlord

My LED lighting is 12V and is connected to a 24V Fan socket on the Duet2 Wifi.
In the config.g I have limited this connection to 20% of the power.

This should also work with the fan.

LED Light Sektion in config.g...

; LED Beleuchtung
M950 F2 C"fan2" Q500                        ; create fan 2 on pin fan2 and set its frequency
M106 P2 I0 B0.0 C"Beleuchtung" X51          ; LED-Strip (12V) auf Fan 2 / (51 von 255 Stufen = 20%)

In the DWC I have a slider for the brightness of the LED lighting.
If I set this to 100%, no more than the 20% limited in config.g is output.

P.S.:
I just see that I0 (i Zero) in the M106 line could go, it's from my old 2.0 firmware configuration.

Google Translate
--- Original Text ---

Meine LED Beleuchtung hat 12V und ist an einem 24V Fan Anschluss auf dem Duet2 Wifi angeschlossen.
In der config.g habe ich diesen Anschluss auf 20% der Leistung begrenzt.

Das sollte auch mit dem Lüfter funktionieren.

Ich habe im DWC einen Schieberegler für die Helligkeit der LED Beleuchtung.
Stelle ich diese auf 100% dann wird nicht mehr als diese in der config.g begrenzten 20% ausgegeben.

P.S.:
Ich sehe gerade dass I0 (i Null) in der M106 Zeile könnte weg, es stammt noch aus meiner alten 2.0 Firmware Konfiguration.

Norder

Addendum

The X51 in the M106 command line limits this port to 20%.
The setting range is from 0 to 255, with 255 being 100%.
So 50% would be X127

But you can also specify X0.5, which would also mean 50%.
The setting range is from 0 to 1, where 1 would mean 100%.

Google Translate
--- Original Text ---

Nachtrag

Das X51 in der M106 Befehlszeile begrenzt diesen Anschluss auf 20%.
Der Einstellbereich geht hier von 0 bis 255, wobei 255 gleich 100% sind.
50% wären demnach also X127

Man kann aber auch X0.5 angeben, was auch 50% bedeuten würde.
Hier geht der Einstellbereich von 0 bis * wobei die 1 gleich 100% bedeuten würde.

jay_s_uk

@norder that's not how PWM power works. It's still 24v

Phaedrux

@jay_s_uk said in Using 12Vdc fans with 24Vdc powered board:

@norder that's not how PWM power works. It's still 24v

24v 20% of the time is still 24v.

LEDs may not mind as much since they probably have some input smoothing, and may just take some hours off the lifespan.

A fan may handle it for a while if it's a good quality fan. Cheaper ones may just up and die.

Norder

@phaedrux @jay_s_uk
I know that it stays at 24V, but it works wonderfully with my LED light, and has been for several years.

The cheap fan can't stand it in the long run... I haven't tried it yet.
Would I try it? Yes !

But everyone has to decide that for themselves.

A stepdown doesn't cost much like a 24V fan.
Maybe you take the X0.5 solution as a makeshift and order a stepdown or a 24V fan and then change the config.g again!?

This method doesn't harm the Duet, at least I haven't had a problem in that direction.

Google Translate
--- Original Text ---

Ich weiß das es bei 24V bleibt, aber es funktioniert bei meinen LED Licht wunderbar, und das schon mehrere Jahre.

Das günstige Lüfter es auf Dauer nicht aushalten... ich habe es noch nicht ausprobiert.
Ob ich es ausprobieren würde ? Ja !

Aber das muss jeder für sich entscheiden.

Ein Stepdown kostet nicht viel genau so wie ein 24V Lüfter.
Vielleicht nimmt man die X0.5 Lösung als Notbehelf und bestellt sich ein Stepdown bzw einen 24V Lüfter und ändert dann die config.g wieder !?

Dem Duet schadet diese Methode nicht, zumindest hatte ich in der Richtung noch kein Problem.

Phaedrux

Yes, for a fan or LED there is little harm, but definitely do no use this method with a heater.

deckingman

I've had some "success" in blowing up 5V fans by setting the vfan jumper to 12V despite using 20% PWM. I've also had "success" blowing up 5V addressable LED's by connecting them to a 12V psu despite using low PWM. Both those "successes" were by accident, I hasten to add.

jens55

Buck regulators are dirt cheap from AliExpress, maybe a dollar or two. No reason to risk killing a fan or LED's.

dc42

24V fans are fairly cheap too!

Duet 3 boards include a 12V regulator.

mrehorstdmd

A string of diodes (15 or so) or a resistor can drop 12V without creating any PWM problems for the fan or controller.