High Altitude Balloon

Transcription

1 High Altitude Balloon Power Bus Development Team Todd Rogers Aoun Barki Henok Feseha June 2009

2 Faculty Advisors John Wu Bruce Rahn (Mentor)

3 Balloon Setup Balloon Parachute Connection Ring Experiment Box Command Module Antenna

4 Parts of Power Bus Battery Pack (power supply) Micro-converters Casing and boards

5 Li-Ion V 6600 mah PCB protection board Rechargeable Light weight (10 ounces ) Small size (7.0" L x 2.2" W x 1.2" H) Temperature range (-40 C to +80 C)? No memory effect (charge at any time)

6 Battery Testing Room temperature Freezer Design a spreadsheet to analyze how temperature is proportional to battery performance

7 Battery Setup a.jpg

8 A Closer Look

9 1 Amp Results

10 2 Amp Results

11 3 Amp Results

12 Problem Given: Design a Single Source of Power Current source of power is AA and 9V batteries Change from 15 batteries + cases to 1 battery + case Reduce Space and Weight Must be able to connect/disconnect components easily Able to handle future additions

13 Voltage Conversion Goal: To get the most power out of the battery even at lower temperatures Made possible by using High Efficient regulators Efficiency proven with lab testing Regulators are small, and very lightweight Have been tested in a real flight and produced expected results

14 SR7805 Series Voltage regulators / mini-converters 95% efficiency rate. Wide input range (6-32V) Works best for our project because of voltage drops at lower temperatures Able to withstand temperatures as cold as deg Celsius Easy to implement in a circuit.

15 Efficiency Testing Tests done with different input voltages and output currents to find the point where maximum load and highest efficiency meet Input V vs. Efficiency Output Current vs. Efficiency

16 Graphs: Output current Vs. Efficiency SR Output Current VS. Efficiency SR W Output Current Vs. Efficiency 94% 95% 93% 92% 91% 90% 89% SR Output Current VS. Efficiency 90% 85% 80% 75% SR W Output Current Vs. Efficiency Boost Buck Converter. Output Current vs. Efficiency SR W Output Current vs. Efficiency 100% 80% 60% 40% 20% 0% Boost Buck Converter. Output Current vs. Efficiency 94% 92% 90% 88% 86% 84% 82% 80% SR W Output Current vs. Efficiency

17 Boost Buck Converter Astrodyne Model # ASD10 Wide 4 : 1 input range High Efficiency Regulated Output of 12V.

18 Power Bus for the Tear Drop Coaxial connectors Easy connection to 5, 9 and 12V from the battery Slots for battery, and several other components in one box

19 ACS712 Low Current Sensor Sensor gives precise current measurement for both AC and DC signals Measures up to 5A of DC or AC current. Small & Inexpensive

20 Accomplishments Calculated Efficiency Build boards to be mounted on the power bus case. Build connecters for the equipment Cold Test regulators with the Bus Send the power bus up with the new package for a final test.

21 Pictures

22 Basic model Not Including the 3.7V

23 Final List of Regulators SR W : Outputs 5V Input Range : 6-32V SR W : Outputs 9V Input Range : 6-32V Boost-Buck Converter : Outputs regulated 12V

24 Boost Buck Converter Boost-Buck topology will allow the DC input voltage to be higher or lower than the output voltage. With temperature changes, during flight, the converter will ensure a constant 12V supply to units requiring Vin of 12V We are using Model # ASD10

25 Boost Buck Converter Astrodyne Model # ASD10 Wide 4 : 1 input range High Efficiency Regulated Output of 12V.

26 5V Equipment

27 3.3V for GPS Units

28 12V & 9V Equipment

29 Upcoming Schedule For Regulators Calculate Efficiency Build boards to be mounted on the power bus casing. Build connecters for the equipment Cold Test regulators with the Bus Send a test board up with the old package to calculate efficiency in real-time

30 ACS712 Low Current Sensor Sensor gives precise current measurement for both AC and DC signals Measures up to 5A of DC or AC current. Small & Inexpensive

31 Efficiencies Not Included: Converters Tested With Loads Voltage Tested Theoretical Current Resister Used (Ohms) Output current SR W 5 500mA Full ma SR W 5 250mA half ma SR W 5 no load 2 ma D112ER 9 111mA Full ma D112ER mA half ma D112ER 9 No load 15mA 12 ma

32 Power Bus Casing

33 Top Box Switch

34 Circuit Board

35 Cost Equipments Cost Converters $100 Connecters $10 Switch s $4.50 Circuit Boards $3.50 Total = $118

36 Conclusion HIBAL What is HIBAL? Our main objective and solution Centralized Power bus system Battery Micro-converters, voltage converters Team is on schedule

37 Contact Information Todd Rogers Aoun Barki Henok Feseha

38 ANY QUESTIONS????