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Power Distribution Control Unit. Michael Davies Andrew Mountain Dan Hoang Daniel Brink. Functionality. Power Distribution Control Unit for Colorado Space Grant’s Satellite Citizen Explorer
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Power Distribution Control Unit Michael Davies Andrew Mountain Dan Hoang Daniel Brink
Functionality • Power Distribution Control Unit for Colorado Space Grant’s Satellite Citizen Explorer • Implement commands from the satellite’s flight computer to provide the desired power to the unit’s subsystems • Monitor specified temperatures and power buses
Distribution of Power • 17 – 4-Pin solid state relays • Control using 5V logic • Direct I/O with PIC • Connected with desired voltage
Temperature • Voltage Divider • Maximum range voltage – low power consumption • Analog multiplexer • A/D converter on chip
Power Supplies • Rigorously test power supplies • Power draw on each bus • Concern with noise on 5V power bus • Pi-Filter near each chip that require 5V
PCB Board • 4-Layer Board • 2 Parallel 7.15" X 7.65" boards • Through hole parts for stability 7.15" X 7.65"
Parts List • Microcontroller: PIC 16C77 • Relays: DMO063 • Clock: ACH-20.000MHz • Thermistor: YSI44901 • 12v to 15v/-15v Converter: JR12D15-330 • 12v to 24v Boost Converter: SI12S24-1250 • 12v to 5v Converter: LANC1205W5S • Flight Computer Interface: RS485/422 Max3082ESH • PC Interface: Max208CN6
Basic Software Functions INITIALIZE VOLTAGES DELAY CURRENTS TEMPS SEND INFO?
Basic Software Functions SET ANALOG SWITCH POS 1 VOLTAGES SAVE VOLTAGE 1 SET ANALOG SWITCH POS 2 SAVE VOLTAGE 2 SET ANALOG SWITCH POS n SAVE VOLTAGE n A/D CONVERSION RETURN
Basic Software Functions INTERRUPT TRANSMIT RECEIVE OTHER? RETURN
Basic Software Functions RECEIVE READ BYTE SET RELAYS SEND INFO RETURN
Basic Software Functions BOOT SEQUENCE CD&H 1 min delay REQUIRED -extra delay for FC ADCS 3-5 sec delay Mnet 3-5 sec delay ARBITRARY Science 3-5 sec delay Deploy
Division of Labor • Michael Davies: Software • Andrew Mountain: PCB/Schematic Design • Daniel Brink: Hardware layout • Dan Hoang: Hardware/Software interfacing
Milestones • Milestone 1: Completed Prototype (wire wrap) and interface-able test code • Milestone 2: Completed PCB Design and ready to order (first revision) • Design Expo