I had some time this evening to assemble a prototype for the power supply.  It immediately drew 1amp and started to blow up a capacitor.  Not good.  I’m not completely sure what was wrong.  The only deviation had been using a 1N5818 diode instead of a 1N5822 on the feedback circuit.  I don’t think this is critical and it looks like it’s used to bleed down voltage when the circuit is off.

There were a number of minor things wrong, so I incorporated some changes and made v1.2   The input/output headers weren’t labeled and were too close together for screw terminals.  The diode pads were drilled too small and too close together, i.e. I used the wrong package size.  I also didn’t like the input and output side by side.  I also changed the package layout for the IC.  I’m not going to bend the thing over on it’s side.  That’s silly for this application.

I ordered new boards from OSHPark tonight.  Should have them in a couple of weeks.

The new board layouts:

OrangePS1.2 OrangePS1.2-btm

Old board layouts:

front bottom

One Response

  1. Nice revision…do you have a heatsink on the vertical LM2576 chip. I’m suprised you didn’t use a surface mount IC on a large copper pour for heatsinking. Either way..have you tested them..do they work well?