StepDown 24V-->12V for Noctua Fan

alankilian

@d0minik96 said in StepDown 24V-->12V for Noctua Fan:

But how can it be broken, when it works without the fan.

Well, it's not working properly when connected to the fan so I think it's broken.

Do you have something like a turning or brake lightbulb from a car or motorcycle you can hook to the converter instead of the fan as a test?

d0minik96

@alankilian sadly i dont have anything like this. Tested 3 different ones tho and cant believe all are broken
I think is an electrical issue but i dont know what to do next, so my printer is idle for a while now again..

alankilian

@d0minik96 It's too bad you don't have anything to test with.

You can even try using a lightbulb from your house. (Not an LED bulb)

I live in a 120 Volt country, and a 65 Watt incandescent lightbulb drew about 0.25 Amps at 12 Volts when I connected to a power supply.

Can you try that?

jens55

@alankilian, based on no connection to the duet and the way things are connected, I am taking a guess that your voltage readings are not giving you a true value. It is possible that the fan electronics are not playing nice with the down converter but my bet is on the meter not giving you a true picture of what is going on on the output.
I agree that it is highly unlikely that all the converters you have tested are defective. That kind of converter is extremely common and I have a bucket full of them myself with never a failure.
Is the fan running at a reasonable speed or is it trying to lift itself into orbit?
Use a real multimeter to measure what is happening.

alankilian

@jens55 If you go to the Amazon link for the converter and read the comments, several people got 3 out of 5 converters arrived broken, so it might be that this manufacturer is building poor-quality converters.

GeneRisi

@d0minik96 A circuit under load doesn't always behave the same way as when it is very lightly loaded. The volt meter probably presents a very high resistance / light load to the converter. As others have said, there is probably a bad component or a broken trace on the board

d0minik96

@generisi but not on 4 of them.

alankilian

@d0minik96 What do you think the problem is?

Are you really not able to test with a load other than a fan?

mrehorstdmd

@d0minik96 This is a lot simpler than you're making it out to be. It's a 12V fan. If it runs properly when you connect it to the DC-DC converter it's fine. A 12V fan will run extra fast and will probably burn up in short order if you connect it to 24V. Is the fan behaving normally? Did it burn up?

d0minik96

@mrehorstdmd
I dont think this is true. I measue the voltage drop over the Fan with a Multimeter. Its 24V. The Fan can handle 24 v but Not for a lang duration.

It is Turning fast, but since i have no reference i can Not say if it too fast or Not.

I will check tomorrow my wiring, mabye there is something wrong with the wires from my artillery, i dont know. But im Sure the stepdown converter works as it should, just Not with the Fan.
As i tested the with this liste voltage Display for drones that i had flying arround.

I would say im pretty fit with Electronic but this duet conversation is just a night mare for me so far. Did Not find anybody with the same Issue, so must be wiring or some electrical Circuit issue

alankilian

@d0minik96 Maybe add a capacitor across the step-down converter's output terminals.

Something like 1000 microFarads should be enough to smooth things out if the fan is doing something that gets the converter to fail to control its output voltage.

jens55

@d0minik96 said in StepDown 24V-->12V for Noctua Fan:

@mrehorstdmd

I will check tomorrow my wiring, mabye there is something wrong with the wires from my artillery, i dont know. But im Sure the stepdown converter works as it should, just Not with the Fan.

You stated that you went from the power supply to the converter to the fan .... are you now saying that other stuff is attached anywhere?
If so, remove whatever else is hooked up and then see what you get!

d0minik96

I did some more testing:

The buck converter works. I directly solderd my fan to the buck converter and i had 12 V on the fan and the fan was moving quieter than before.

But after using the cables of my Artillery it is running with 24 V again.

So there must be a problem with the wiring. I am using the preinstalled
ribbon cables of my Artillery. There is a small pcb inside of the printer where the cables change from ribbon to normal. Im sure that i have the right pair, as the fan is not moving when disconnect this 2 specific wires. My guess is that on the PCB is something that converts my 12 V to 24 V but i am not sure why. I will check google if this is common Artillery problem....

dc42

@d0minik96 said in StepDown 24V-->12V for Noctua Fan:

I did some more testing:

The buck converter works. I directly solderd my fan to the buck converter and i had 12 V on the fan and the fan was moving quieter than before.

But after using the cables of my Artillery it is running with 24 V again.

So there must be a problem with the wiring. I am using the preinstalled
ribbon cables of my Artillery. There is a small pcb inside of the printer where the cables change from ribbon to normal. Im sure that i have the right pair, as the fan is not moving when disconnect this 2 specific wires. My guess is that on the PCB is something that converts my 12 V to 24 V but i am not sure why. I will check google if this is common Artillery problem....

Most likely that PCB is using a common positive wire for the hot end heater and the fan.

d0minik96

@dc42 yes i just found out, that the 24V line is shared, so that is where my problem is comming from. I solved it by placing the buck converter between my PCB and the Fan at the hotend.

jens55

... and this is why I am reluctant to help people over the internet. You just can't rely on them to convey the true nature of the situation. It is always tainted by the same mind that can't see the forest for the trees.
If we had known that the wiring involved the printer rather than going straight from the power supply to the buck converter and straight from the converter to the fan then instead of 22 posts on this issue it would have been just a hand full.

That's a whole lot of people trying to help one person that can't be bothered to fully explain how things are connected.

d0minik96

I'm sorry that i wasted your lifetime. Ty all for your suggestions. Helped me to find the problem !

alankilian

@d0minik96 said in StepDown 24V-->12V for Noctua Fan:

Ty all for your suggestions. Helped me to find the problem !

Hey, you got a working step-down converter and fan, so it's all good.

I hope next time when someone says "...just in case you missed something, can you post a photograph of your wiring and maybe a video of your testing?" you can take the time to do that. I could have saved you a lot of time and frustration.

MarkJohnston09

I have also checked the converter with my drone DJI Mini, and it worked quite well.