source of voltage near the nextruder?  

RE: source of voltage near the nextruder?

The Love Board filament sensor connector has 3V3 output pin. I suppose you could attach something inline there: https://www.prusa3d.com/downloads/Electronics_drawings/FDM-MK4-LoveBoard-38.pdf

RE:

There is a +5V supply on pin 14 of the large connector (to the main "umbilical cord") on the LoveBoard. The +5V supply also shows up in a few other places on the LoveBoard -- see the attached circuit diagram.

Are you sure about the stated current? 50 µA would be very little for an LED. Might it be 5 mA or (for illumination purposes) even 50 mA = 0.05 A?  In any case, make sure to provide a suitable series resistor to limit the current.

Edit: Ah, hyiger beat me to it... I would prefer the +5V supply, especially if you want to use a blue or white LED; gives you more headroom for the series resistor. 

RE: source of voltage near the nextruder?

Thanks, Jürgen. You are absoulty right. 0.05 A, or 50mA. 

Thanks for the suggestion and the circuit diagram.

Tom

RE: source of voltage near the nextruder?

I was planning to do something similar (bling out the Nextruder) but then it’s going to get removed in a month or two. Let us know how your project goes!