Power Stack V1

This power stack will be a major redesign from previous iterations. The main goals of this version are to separate the thruster power from the regulated board as well as integrating dedicated 12V lines for devices like the Jetson. Future revisions will also allow for the automatic shutdown of certain power lines in the event of a critical battery drop. This will all be controlled via an Arduino and allow for more to measure critical systems and display them during things like water tests as well as collecting data. Future plans have been discussed about adding a micro-controller such as an ATTINY for a smaller overall package.

Major changes from previous designs:

12V lines- Previous iterations made use of 10V lines to provide power to the Jetson but power transients due to thruster draw has necessitated the use of an external 12V regulator to ensure a clean supply of power that the DVL can also work off of. The new design will use 2 separate 12V 6A lines to power the Jetson and other peripherals. Initial prototypes will likely not include this functionality but final revisions will include the ability to shut down one of the 12V lines but keep the Jetson operational in the event of a critical power situation. This is meant to prevent an over-discharge from the battery but still allowing for a proper shut down of any systems/data collection before fully powering down.

No more fuses- It has been determined that fuses are unnecessary and that transient suppression is the primary need to protect sensitive components. Additional capacitance and diodes have been added.

Micro Controller Integration- Adding a micro controller is desirable to have more integrated control over monitoring and commanding the power board. This device could also act as a low cost option for a replaceable serial interface driver to further protect more expensive equipment like the Jetson. A usb connection can easily be run to the rear of the board creating a robust line of communication between the Jetson and power board. Current plans are to use an Arduino seated onto header for ease of use. Future plans are to add a microcontroller directly to the board (Likely in V2 rather than a future revision of V1).

Separation of regulated and thruster power- A lot of space on previous boards was taken up by the thruster connections and power lines to the battery. The traces carrying power to the thrusters were also not able to carry enough current to the thrusters without additional copper/wire soldered to the back of the board. Having a dedicated distribution board will allow for heavier copper pours on a 2-4 layer board. This will bring down the per board cost while allowing the regulated power board to have an increased layer count if necessary.

Rev B Planned Changes

Integrate control for all power lines independently. Maybe isolate Arduino onto a separate 12V line to allow for power cycling of the Jetson and all other lines but maintain control over the Arduino (for timeouts and true power cycle control). This would be done using PMOS logic to allow for operation even if there is no Arduino connected.

Add jumpers to the board to easily control the "key" without needing an external custom connector and other toggles like thrusters.

Increase silkscreen legends for more ease of use and easier identification for users less familiar with the pinout and operation of the board