Purpose of Document

Complete review of the EPS board version 1.

High-Level Overview

Generation

Component	Overview
Solar panels	Gathers energy from the sun 😎
Solar panel protection	Protects against reverse, short current, overvoltage
“Voltage regulator” MPPC	Regulates output voltages of the solar panels
Load sharing component	Takes in 3 sources and combines them to create 1 source/output

Why did we put them connect the solar panels as we did? What is our reasoning behind the configuration?

All in series - lots of voltage drop from the diodes if shading happens
Mounting complications - it’s hard to connect solar cells that are on different sides of the Cubesat so we avoided doing that

Schematic Review

The three solar panel strings are fed through individual LTC3130 (MPPCs / buck converters) to regulate the power coming out of the panels. These regulated power supplies are then fed into the LTC4370s (load sharer) in a cascaded manner to provide load sharing across three sources and create one output.

Solar Panels

MPPC - LTC3130

Current Balancing Controller - LTS4370

Storage

Component	Overview
Batteries	Stores the energy from the sun; 2p2s
Battery Charger	Manages power going into batteries
Battery fuel gauge	Controls how quickly the batteries charge and discharge
Battery Protection & Balancing	Distributes energy amongst multiple loads evenly
Current monitors	Monitors current :)

Schematic Review

The unregulated output from the Generation stage is connected to the battery charger. The battery charger will take in power to charge batteries and send out excess? to the rest of the system.