This module will be a simple power regulator for the rest of the balloon modules. It will regulate the power from a common voltage battery pack out to several required voltages.
A large stack of parallel lithium AA Energizer Ultimate Lithium battery packs will supply raw voltage of 3 to 4v. There will be several stacks in parallel to provide for long duration operation.
Power output should be:
| 12v | 2A |
| 5v | 1A |
| 3.3v | 1A |
This will connect to the main White Star Bus, providing power to all other modules connected to said bus. Please see the hardware specs for the White Star Bus 7-Pin connector. The connector must implement power as well as I2C communications.
The Temp sensor that extends into the battery pack should be logically on the main I2C bus, but the power controller microcontroller needs to identify it in device scans.
The single battery pack will need to connect to the power controller with a connector of some sort mounted on the controller PCB.
| Connections | |
|---|---|
| Pin | Purpose |
| 1 | GND |
| 2 | Batt V+ |
| 3 | Heater Vcc |
| 4 | Pack Temp Sensor ? |
| 5 | Pack Temp Sensor ? |
This module will need to dump heat from the voltage regulators into the actual battery pack. Arrange the regulators on the board so that they are in contact with, or within 5mm of, the battery pack. This module will be the only electronics inside the insulated battery pack chamber, for the purpose of utilizing waste heat from the regulators to heat the batteries.
TI TMP512 - This chip looks like it would kill two birds with one stone!
TI TMP101 - This tiny SMD temp sensor is also a settable thermostat that could control the heater automatically.
max4172 Current monitor and used current accumulator. This chip will tell us how much current has been used in mAh! However, it only works from 3.3v to 5v. No 12v.
DS2741 Current monitor and used current accumulator. No 12v
DS2745 Current monitor, accumulator, voltage sensor, temp sensor