Boards Arrived, More Holder Tweaks

A project log for TI-59 LiPo Battery Pack

A modern replacement for the TI-58/59 Calculator BP1

tomcircuittomcircuit 01/22/2021 at 04:300 Comments

The PCBs arrived today, and the first board went together well. I had neglected to order the correct USB receptacle earlier, so that’s not populated yet. Those will arrive next week, but for now I can charge the battery using my HP pack boards. 

I was a bit overzealous on making sure the TI contacts would touch the PCB pads. The PCB was so far into the cavity that the attachment screws and the “charging indicator” LED collided with stuff inside the TI-59 and prevented lid closure. So, I quickly tweaked the holder model by reducing its height by 2mm and printed a new one. Perfect fit in two of my TI-59s and with the holder latched I was rewarded with a running calculator.

Tomorrow I’ll print a couple more and check fitment in a few more calculators. I will also connect an AC adapter and ensure the ideal diode and zener protection is working as expected. If all is well I will upload the revised OpenSCAD holder model (ver 0.6 for those keeping track) and some assembly photos. Final release will have to wait for those pesky USB receptacles to arrive...