Next Prototype PCBs arrived

January 8, 2014 in 8 Channel PDU by Joshua Oster-Morris

The new PCBs arrived a couple days ago. I got 100 of each type (Power & Logic). I noticed right away that the holes drilled and plated for the power terminals were too small. It took a couple of days to come up with a procedure that will allow me to use them, and it remains untested, but I expect it will work. The vendor believes they met the agreed upon specification but I am unconvinced. I am having a calibrated measurement being made now and we should have some clarity as to the solution going forward (we are arguing over about 40 microns). The boards as is will not work for production (because the assembly labor is excessive), but they should be usable for prototypes which is good enough. I’m more concerned about the time cost of running to boards than I am about the dollar cost of producing another run at this point so I’d rather just move forward if at all possible.

You will notice in the photo below that I got rid of the spade connectors in this iteration and instead went with high current power bushes. These screw down terminals are waterproof and very high current capable. Plus they will package up nicely in a retail box and will be comprehensible to the users without being “scary” looking with a mass of wires hanging everywhere.

The logic boards have only modest changes. The only significant update is the 4 addition analog inputs (a total of 8 now) and the way I bring the inputs lines out of the device. I’ve got a standard header which I will use with a sacrificial breakout board which will cheap to replace and easy to change going forward. I went with maximum future flexibility solution.

I’m going to build up prototypes ASAP and get them tested and shipped out to a few prospective customers for testing.