Motivation

Currently, Big Red Bee is the only electrical component that’s not powered by the CAN bus. The battery is charged outside then loaded into the rocket before tower raising. With the upcoming on-pad charging project to prolong the duration the rocket can stay on the pad, it becomes important for Big Red Bee to be able to recharge inside the rocket as well. This project aims to design a board that can charge and power on/off the Big Red Bee without physical access to it.

Description and Requirements

• The system must be able to charge Big Red Bee without disassembling the rocket

• It is not required to be able to charge while the rocket is raised

• The on/off switch must be simple and reliable

• BRB should be off while charging to simplify the charging circuit and/or use an existing charger

Scope

• Finding a way to access BRB electrically on the nose cone

• Designing a PCB to incorporate BRB, battery, switch, and connector

Documentation

• Charging connector pinouts

• Charging procedure and preflight checklist

Timeline

• Sept 25 complete electrical component part list, schematics reviewed

• Oct 2 PCB and parts ordered

• Oct 15 nose cone connector prototype demo

• Nov 13 PCB full functionality tested

• Nov 30 prototype integration test

• Jan 31 final design demo

Cost

PCB itself should cost less than $10, it’s not too complicated. For the charger, we might be able to use the existing chargers we have.

Nose cone wise, there’s no concrete idea on how to implement yet. But it probably involves drilling some holes and filling them with connectors, and shouldn’t cost much extra to the existing nose cone cost.

Integration and Stakeholder

• Need to work with airframe to see how to break out electrical contacts out from the nose cone

• Need to make sure the new mount doesn’t interfere with parachute lines for recovery