Michael Davies Andrew Mountain Dan Hoang Daniel Brink
description
Transcript of Michael Davies Andrew Mountain Dan Hoang Daniel Brink
Michael Davies
Andrew Mountain
Dan Hoang
Daniel Brink
Michael Davies
Andrew Mountain
Dan Hoang
Daniel Brink
Power Distribution Control Unit
Power Distribution Control Unit
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
Schematic
• 17 – 4-Pin solid state relays
• Control using 5V logic
• Direct I/O with PIC
• Connected with desired voltage
Distribution of Power
Schematic
• Voltage Divider
• Maximum range voltage – low power consumption
• Analog multiplexer
• A/D converter on chip
Temperature
Schematic
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 stability7.15" 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
Microcontroller
Relays
ThermistorsTemperature Resistance Characteristic
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
-40 -20 0 20 40 60 80 100 120
Temperature [celcius]
Res
ista
nce
[o
hm
s]
Flight Computer InterfaceSerial Communication
PC Interface
Basic Software Functions
INITIALIZE
VOLTAGES
CURRENTS
TEMPS
DELAY
SEND INFO?
Basic Software FunctionsVOLTAGES
SET ANALOG SWITCH POS 1
A/D CONVERSION
SAVE VOLTAGE 1
SET ANALOG SWITCH POS 2
SAVE VOLTAGE 2
SET ANALOG SWITCH POS n
SAVE VOLTAGE n
RETURN
Basic Software Functions
INTERRUPT
RECEIVE TRANSMIT OTHER?
RETURN
Basic Software FunctionsRECEIVE
SET RELAYS SEND INFO
RETURN
READ BYTE
BOOT SEQUENCE
CD&H
1 min delay
ADCS
3-5 sec delay
Mnet
3-5 sec delay
Science
3-5 sec delay
Deploy
REQUIRED
-extra delay for FC
ARBITRARY
Basic Software Functions
Schedule
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