Nova's Power System Nova's power system takes power from the battery pods and converts it into regulated voltage for sensors and the computer. It provides 5V, 12V and 24V at different points.
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Each battery pod contains a single Thunder Power RC 22.2V, 4450 mAh Lithium Polymer Battery. A circuit board provides overcurrent and overdischarge protection, communication with the rest of the vehicle, and status monitoring. These functions are provided through a fuse for over-current protection, a comparator for under-voltage shutdown, and a dedicated fuel gauge IC that measures voltage and current flow to provide precise Coulomb counting and full charge detection. The LED fuel gauge bar graph can be activated manually by a reed switch, through serial communication and automatically when the remaining capacity changes. |
Aft Power Board
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The Aft Power Board draws power from the vehicle's battery pods, merges this power into battery voltage that is distributed throughout the vehicle. Signals from the battery pods are routed through the board to the Serial Board. Aft Power converts the battery voltage into an isolated 12V to directly power the CPU. The board measures current draw from the CPU, and provides these signals to the Sensor Power board. The 12V supply is also distributed to up to 4 fans. Temperature sensing is also performed, and this signal is provided to the Sensor Power board. The battery voltage is supplied directly to the Thruster Board and the Sensor Power Board. |
Sensor Power Board
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The sensor power board is responsible for distributing power to that various sensors on the vehicle. It receives 24V from the batteries and runs it through various DC/DC converters to output 5V, 12V, and 24V. It also monitors current use of the sensors, shutting power off if the sensors draw more than their pre-specified amount of power. It is responsible for reporting voltage levels and power use to the CPU through the serial board. A secondary responsibility of the sensor power board is using its ADCs to handle raw output data from the Aft Power board. |
Thruster Control Board
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The motor controller board facilitates the computer’s control of the actuators. It communicates with the computer through a RS232 connection and listens for commands to drop markers, change thruster speed, or requests for current status. It also contains the switches for the vehicle, which include kill/unkill, on/off, and mission start. The current design is able to control two marker droppers, one torpedo launcher, and eight thrusters. The marker droppers and torpedo launchers are either enabled or not and share a single fuse and current monitor. Each thruster has an H-Bridge which has its direction and speed controlled by the microcontroller. Each thruster also has its own fuse and current monitor. Actuator Conrol Datasheet |
