UMO temperature noise SOLVED

[ekh 3]

Hi,

This is my first post.

I have had an Ultimaker Original for a year and an Ultimaker 2 for 2 months.

On the UMO I have experienced noise from the amplifier pcb on the printhead.

It resulted in arbitrary "fishnet" layers due to too low temperature caused by temperature noise.

The cause of the problem is an unstable supply voltage for the operational amplifier.

When you have a pcb with many IC's and low inductive supply planes, then a 100nF decoupling capacitor for each IC do a good job.

But the pcb on the printhead sits in the end of approx 1m cable with self inductance.

I soldered a 1uF ceramic capacitor on top of the existing decoupling capacitor, and have not had this problem since.

IMHO the thermo couple solution is superior to a PTxxx solution.

Ekh

Edited July 5, 2015 by Guest

[gr5 2,189]

I emailed a link to this thread to the hardware guy who actually designed the PCB.

[ekh 3]

I emailed a link to this thread to the hardware guy who actually designed the PCB.

 

Thanks, it was a temporary error coming from time to time, had to discard the print each time it occurred. Hope it can spare others from from this annoying error.

[maartenw 6]

Interesting!

Could the temperature noise be related to the item described in fan-speed-influences-reading-temperature-hot-end (and links)?

Could you post a picture indicating where you soldered the capacitor?

[ekh 3]

Interesting!

Could the temperature noise be related to the item described in fan-speed-influences-reading-temperature-hot-end (and links)?

Could you post a picture indicating where you soldered the capacitor?

 

I can't say, sometimes you are fighting more than one error at a time.

But adding noise near the amplifier can be the problem.

What I can say is, that when operated within specifications, parts from Analog Devices do an excellent job. It is one of the most skilled producers of analog IC's.

I have added a picture showing the pcb on the UMO printhead, where an extra 1uF ceramic capacitor has been added upon the original C1.

On my UMO I have seen no temperature noise since this addition.

[ekh 3]