Alternate Power DC-IN on the Euler Bus also with PI filter for batt operation

[MarkHaysHarris777]

   

In this post I have remade the PI low-pass filter so that it can be replicated more easily;  I'm using the Sparkfun solderable mini breadboard and the same components from my previous board-- I've just moved them over to the new board which mimics physically (more precisely) the schematic in the pic above;  the left hand cap is the storage cap, and the right hand cap is the smoothing cap.  The inductor is in the positive feed;  while it does not matter which end of the board is input and output the larger of the two caps would typically be the output end;  in my version the caps are both the same. 

   

The mini solderable breadboard is similar to the plastic pluggable ones; the five vertical pins in each column on the top are connected together; similarly , the five vertical pins in each column on the bottom are connected together.  The components will be moved so that the positive rail is at the top and the negative rail (ground) is at the bottom.

         

The pics above are the new board; top and verso.  The black edge of the board is negative, and the red edge of the board is positive;  it is very important that the electrolytic capacitors are connected to the positive and negative rails in the right orientation (the neg lead has the silver band) or else they will explode when the power is connected !

   

The pic above is the finished PI filter connected for use with the Rock64 board, or the Pinebook.  Remember check twice, plug once;  reversing the polarity of the wiring is disastrous for the capacitors !