Electrical System
Overview
The increased enclosure length allows all electronics to be housed with 3 layers instead of 4 to allow for ease of access within Onyx’s 8 inch diameter chamber. This will also increase heat dissipation within the enclosure. Further thermal management include various heatsinks and fans, which route hot air toward the aluminum end caps. The aluminum will conduct this heat into the water surrounding the enclosure.
System Diagrams
Custom PCB
For our power distribution board we designed a PCB (Printed Circuit Board). The controller swaps batteries when the active one drops below 12.8V. If both batteries are below 12.8V, they will be put in parallel until they die (you need to replace them!). If a battery is removed, the controller will automatically swap to the battery that is installed.
Onyx’s custom PCB is based on Græy’s electrical architecture and unifies the power distribution and conversion functions within one compact board. Combined with a microcontroller, the Unified Power Controller is capable of managing hot-swapping between batteries, intelligent error reporting/datalogging, control from external computer, and temperature monitoring. The hot-swapping system gives our sub over 1.5 hours of runtime on both batteries while allowing us to install new batteries without turning off any part of the sub. Additionally, swapping between batteries allows us to better maintain the health of our batteries for future tasks.