Transcript Hot Dog Solar Powered Heated Doghouse

Solar Powered Heated Doghouse
Lynn Deasey
Krista Giacobazzi
Gurbaaz Sidhu
ECE 445 Senior Design
Spring 2013
Group 5
Introduction

The desired temperature specified by the owner is
maintained

Thermistors send feedback to the circuit that determine
whether to turn the heating on or off

Generates power via solar panels

Battery for energy storage

Heating element underneath the floor to provide heat

Fans to cool the interior during summer months
Outline

Design

Fabrication

Requirements

Verification

Problems

Ethics

Summary

Questions
Design

On/Off
Switch
Top Level Schematic
Battery
Protection
Charge
Controller
18 V → 12 V
Solar Panel
18V
+
12 V
Battery
-
Heat
Controller
and
Element
Cooling
Controller
and Fan
Design

Original Battery Protection Schematic
Design

Revised Battery Protection Schematic
Design

Heat Controller Schematic
Design

Cooling Controller Schematic
9.1 KΩ
Fabrication

Battery Protection Board
Fabrication

Heat Controller PCB
Fabrication

Cooling Controller Board
Fabrication

Doghouse

Control Panel

Floor

Enclosure

Fan

Panel supports

Thermistor/Wire
Requirements

Solar Panel


Charge Controller/Battery



Solar panel must charge the battery
Battery must not be overcharged
Charge controller must step down the panel voltage to 12-14V
Battery Protection Circuit

Turns off the load current when the battery goes down to 10.5 V

Turns on the load current when the battery goes back to 12.5 V

Load current turns off when load current exceeds 5 A
Requirements


Heating Controller

When the house is cooler than desired temperature setting, the controller
sends power to the heating element

When the house is warmer than desired temperature setting, the
controller turns off power to the heating element

If the floor reaches 102°F the heating element shuts off regardless of
temperature setting
Cooling

When the room is cooler than 65°F the fans should not run.

When the room is warmer than 80°F the fans should be on high

When the room is between 65 and 85 the fans should be on low
Verification

Solar Panel/Charge Controller/Battery

Battery Protection
Current Supplied to Load (Amps)
Current Supplied to Load vs. Voltage Across Power Supply
5
1) Start input
voltage at 12.8 V.
2) When input voltage is 10.5V
current drops to 0 A.
4
3
3) Once voltage
reaches 12.5V the
current goes back
to about 4 A.
2
1
0
10
10.5
11
11.5
12
Voltage Across Power Supply (Volts)
12.5
13
Verification

Heating Controller- With 13.3V from power supply
105
100
95
90
85
80
75
70
65
Heater turns off.
Reached setting
Heater turns off.
102°F reached
Heat setting
increased to max
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
105
110
115
Temperature of Floor (°F)
Temperature of Floor vs Time
Time (minutes)
Verification
Fan Controller

Voltage Across Fans vs. Temperature
Voltage Across Fan1 (Volts)
14
12
10
8
6
4
2
0
HOT
80°F
Temperature
65°F
COLD
Problems

Failed Verification



Battery Protection Circuit

Small transistor blown due to current

Reworked with BJT and relay

Switch failed, during debugging attached capacitor, blew op amp chip.

Redesigned board using relay and BJT, added hysteresis
Heating Element


Battery
Shortened length and condensed element pattern to under two tiles to increase
effectiveness
Fan Controller

Delay in PCB fabrication required us to use vector board

Also adjusted base resistor for lower fan speed
Ethics

Safety of dog
 102°F
safety
 Waterproof
 No
boxes for circuitry
exposed wires
 Moisture
 Current
resistant floor
limiting fuse
Summary

All of the requirements and
verifications were met except for
the battery.

We were able to successfully demo
all components separately as well
as all together.

We ended with a fully functioning
deployable temperature controlled
doghouse.
Special Thanks

George Middleton



Construction
PCTEL

James Giacobazzi

Steve Brown
ECE Staff and Part Shop

Mark Smart

Kevin Colravy
Questions?