This is a bump to keep this topic from slipping into the abyss.
Things are at a standstill pending yet another surgery on my left eye, which at close range is functionally blind right now. Oddly enough, I can see distant objects with some clarity, which means I can still drive an automobile. I just can't do much in the way of close-up work.
I was able to assemble a prototype module that will be part of our line of railway riding scale automatic block signal system (ABS) modules, but it's all through-hole parts, many with large spacing between the pins. It was a struggle to solder in a DIP-8 package and I did get one accidental bridge between two pins. I also managed to install two transistors (TO-92) backwards.
After tracking down and fixing this stuff the module worked. However, I was pushing it trying to do this assembly work, and this experience definitely tells me I'm not ready to tackle POC V2 with its much tighter parts spacing.
Attachment:
File comment: ABS Module Undergoing Test
dbod_proto01.jpg [ 1.55 MiB | Viewed 1194 times ]
Incidentally, the PCB for this unit was made by a
USA company called EPEC. I generated the PCB layout in EPCB, used Copper Connections to convert the EPCB file to Gerber and shipped the Gerbers in a ZIP file to EPEC. The cost for 15 boards was about 25 percent less than if I had used EPCB's production service for the same quantity. In addition, EPEC does some QC checks on the boards (including a hi-pot test) that EPCB doesn't do, and includes a QC report with the shipment. The bare boards are UL recognized, which can be useful in Canada, the USA and some other countries that recognize the
UR mark. I was quite pleased with the product, which was as good as EPCB's in all respects.
We have a pretty substantial order pending for ABS modules of several types, which is was prodded me into finding an alternate to EPCB for board production purposes. I've never had a complaint with EPCB's product, but also have been underwhelmed with their production pricing, which is more like prototype pricing from other board houses. After reviewing a number of houses, I decided to place a small order with EPEC to see what we would get for the money. Their stuff is good, so they will be getting the entire order for all PCBs in the set of modules we have to build.