Feedback noise from power supply


i took my time and finished bulding after 45 hours. I took care of every detail
as much as i could

After first try - here is the result

but then i noticed my internet was down
Several changes in using different power plugs didn’t solve the issue that
the printer power supply generates some nasty noise on the power main line in my house
which kills the DSL modem internet connection
I’m using a Fritzbox WLAN 7360 and it’s the the DSL connection (not WLAN) that drops as soon the 3D printer
starts (during printing). I tried direct LAN connection between PC/modem but it didn’t help
Currently i cannot do anything with the 3D printer because others need the internet too
I’m disappointed. What can i do ?


Does not the mains lead supplied with the PS come with a ferrite core to damp interference?

I thought this was to protect the printer circuitry though.


This is solved now

I used 4x 15V á 1.6 A in parallel

If you ask me 100Watts are overdosed
They not even get really warm after 6 hours printing
(60€ without plug connector)

The internet connection works fine now during priniting
Also the snow storm from Webcam is gone, which already appeared after just plugin
of original Velleman power supply


LOL? Thats quite an original solution. Not one Id have picked to be honest, I have terrible experience with these small USB style PSU’s, but if it works for you, so much the better :).

Im actually looking to upgrade my stock PSU to accommodate a more powerful heated bed, and came across this: … wer+supply

Just FYI, not endorsing it, havent tried it yet.

You should probably ask some of your electronic engineer friends before you decide to do something like that. It’s completely insane to do something like that and it can be quite dangerous as well.
Those cheap wall warts are never 100% equal. In fact, they can have quite big tolerances as they are meant to be used in front of some regulation circuit and therefore do not require to be accurate at all. This means that they are uneven loaded. When that happens, one starts to take up all the load and the others lose theirs. This results in either a burning wall wart, or if you get lucky, in a broken thermal fuse (as those cheap ones never come with a real protection circuit as well).

~ Tectu

Actually the voltage level drops if the load gets higher on one PSU that’s when the
others kick in . After all they sync their voltage level themself and the load is always
nicely distributed over the PSUs which can be seen with watt meters measured over longer period

The link for the heatbed PSU? This is a 12V/15A which is useless because resistance of the
heatbed is still the same. You would need higher voltage (then 15V) to get the juice running
(and better cables). Why do you need this ?


Sorry wrong link. … ds=Heng+Fu

Its also 15V but allows for another heated bed with lower internal resistance, like this one: … cPath=1618

I know many use the stock heatbed at 20 or 24V, but Id rather use only 1 PSU and no added electronics.

It certainly looks like it can deliver what the spec says and has earned it’s certification


Hi P4man,

[quote=“P4man”] … ds=Heng+Fu[/quote]
that’s only a 100 W power supply. Depending on the temperature that you want to reach (80 °C? 100°C?) the heatbed alone might use something in the range of 70 to 100 W, so there would be not enough power left for the hotend and motors.

Printing PLA at “low” temperatures should of course easily be possible; at 50 °C (or in other terms: only 30 K above room temperature) the heatbed will need much less power, like e.g. 40 W used in the stock version.


It seems that the no-load voltage fluctuates quite a bit on some K8200 power supplies …

Mine does the same but the driver voltages were steady during calibration so I’m not sure if it’s an issue.

[quote=“OnYerBike”]It seems that the no-load voltage fluctuates quite a bit on some K8200 power supplies …

Mine does the same but the driver voltages were steady during calibration so I’m not sure if it’s an issue.[/quote]
This is a normal thing, don’t worry. Those power supplies are not regulated/stabilized.
As the calibration voltage is generated behind one or two stabilization circuits, that does not matter at all.

~ Tectu