New Input Terminals
On the current version of Motobrain, I have the inputs terminated with 2×4 headers sticking out of the epoxy. I didn’t love this design but I wanted to test some things and I didn’t want to delay my testing while I tried to find the “perfect” solution for the inputs. I created a little “disposable” break out board so I could attach wires to the board with standard tools and attach that board to the Motobrain headers. After seeing and feeling this setup, I recognized it just will not be sufficient for our needs. Much too fragile! I’ve redesigned the board with terminals directly mounted to the PCB which will extend out of the epoxy. I ordered these new boards with an express three day turn around. Likewise, I redesigned the mold and also ordered it to be delivered post haste. I also took this opportunity to add some temperature compensation (in hardware) to the inputs. I found on the current version that the voltage sensed would drift a few volts when we approached the far end of its operating temperature envelope. The new amplifiers I’ve included will not drift significantly over the temperature range specified for Motobrain (-20C to 80C). Lastly, I decided to include a thermal cutoff circuit to the device. If the device reaches 112C, it will shut off. This is hardware enforced, so there is no getting around this. As such, it should so a good job protecting itself from would-be Motobrain killers.
Photos of the current board with break out board and renderings of the new board and mold are below.