Power to the Thrusters

June 22, 2023
Rev A of the New Thruster Power Board in Altium.

The Problem: Overheating Thruster MOSFETS

One of the biggest issues with the old power board was that it couldn’t handle the high current (up to 40A) supplied to the thruster motors - the MOSFETs would regularly overheat, leaving Kingfisher without any thruster power. We are designing a new thruster power board to handle these currents, with large copper pours and 2 Oz thick layers to dissipate the heat. The old MOSFETs have also been swapped out for newer ones by Infineon that can handle higher currents. The board also includes an upgraded Infineon gate driver, allowing for faster switching, as well as an extra power connector that allows us to power a 9th thruster.

Improved Modularity with Inter-Board Connection

Unlike our previous setup, the new thruster board is separate from the regulated power board. A pair of Samtec inter-board connectors let the two boards interface with each other, and hold them in place. This makes our system more modular and thus easier to maintain, since any issues with the thruster board can be addressed without modifying the main board. Also, given the much lower BOM cost of the thruster board, we could have multiple thruster boards ready-to-use and swap them out during competition, if any issues arise with the MOSFETs.

Inter-Board Connectors on the Thruster Board (left) and the Regulated Power Board (right).