1. Solar Cooler
Team 7
Karim El-Najjar
Hanfei Deng
Kunjie Zhao

2. Problem Statement & Objective
Heavy Cooler
Below 25 Lbs.
Ice melts
Must cool 20 C below ambient temperature (without ice)
Cooling time
Cool longer than 6 hours
Karim

3. Introduction Objective Design Spec. Below 25 Lbs.
Lightweight components
Must cool 20 C below ambient temperature (without ice)
Thermoelectric cooling
Cool longer than 6 hours
Solar power
Karim

4. Design - Heat Calculations
time
in hours
Hanfei
Energy in Joules

5. Design - Overall
Kunjie

6. Design - Thermoelectric Cooling Pad
Lighter and no moving parts.
30mmx30mm
Require heatsink and fan to dissipate heat extracted.
2 cooling pads connecting in series, runs at 5V.
Kunjie

7. Kunjie

8. Kunjie

9. Design - Linear Voltage Regulator
LM1084
Need to output 5V to power the microcontroller and thermoelectric cooler pads.
Problem: Not efficient to convert 12V to 5V.
Kunjie

10. Design - Charge Controller
bq24650
Karim

11. Design - Temperature Sensor
R1 = 5kOhms
R2= 6.3kOhms
I= ~0.3mA
Karim

12. Design - Microcontroller
Hanfei

13. Design - 7 Segment Display
Hanfei
LTC-4727JR

14. Thermoelectric Cooling Pad
Results & Verification
Subsystem
Requirement
Verification
Solar Panel
18V * 1.4A = 25.2W
17.4V * 1.3A = 22.6W
Charge Controller
~12V Output
40mV / 72mA
Battery
11 < V < 13V
11.5V (half charged)
Voltage Regulator
4.8 < V < 5.2V
4.99V
Microcontroller -
7-segment Display
Temperature Sensor
2.68 < V < 3.03V
2.8 < V < 3.1V
Thermoelectric Cooling Pad
Karim

15. Conclusion & Future Work
Bigger Battery
Rework Voltage Regulator & Charge Controller
Temperature Control
Karim

16. Questions?