solar energy meter lab

• ENGR 1181 First-Year Engineering Program

College of EngineeringEngineering Education Innovation Center

First-Year Engineering Program

Solar Energy Meter Lab


Solar Energy MeterOn a bright, sunny day, solar energy strikes the earth at therate of approximately 1000 Watts/m2 – this is called the solar energy intensity.

In lab today, you will build a solar energy meter to measurethe energy intensity from the sun at the earth’s surface.


Solar Energy Meter PartsHere are the parts you will use:• +5 Volt modular power supply • DMM*

• Breadboard

* For a detailed explanation of the DMM, see the video from the Circuits Lab.


Solar Energy Meter “Circuit”

This is the circuit you will build:• Breadboard• Switch Box• Light Sensor• TrimPot• Binary Voltmeter• LED Display (8-bits)• Wires for connecting components


Solar Energy Meter “Schematic”

A “schematic” is a drawing of an electronic circuit made by an electrical engineer.

+5 V +5 V+5 V

P C B 1

Light S ensor

5

2 1

63 4

V O

ut

+5V

+5V

V O

ut

Gnd

Gnd

P C B 2

Bina ry Voltm e te r

6

2 1

75 14

4 3

8 9 10 11 12 13

D7

(MSB

)

+5V

+5V

D6

V In

put

Gnd

+5V

+5V

D5

D4

D3

D2

D1

D0

(LSB

)

D 7 D 6

D 5

D 4

D 3

D 2

D 1

D 0

BINA RY DISPL A Y

SHORTW IRE

S o la r E n e r g y M e te r C ir c u it

L EDs


ComponentsThe parts (Components) you will use to build the

Solar Energy Meter are:• Light Sensor Board

• Senses the sun’s energy• Uses a Photodiode and an Op-Amp• Has an analog output voltage signal of 0 – 5 Volts

• Binary Voltmeter Board • Changes the input voltage signal to binary “Bits”

• LEDs• Display an 8-Bit binary number

• Wires• Connect the parts together electrically


Task 1 – Check the Breadboard Setup

Measure the Power Supply Voltage, V = ______ Volts

+5V

Gnd


Task 2 – Calibrate the Binary Voltmeter

+5 V

+5 V +5 V

1 0 K

P O T

13

2

P C B 2

Bina ry Voltm e te r

6

2 1

75 14

4 3

8 9 10 11 12 13

D7

(MSB

)

+5V

+5V

D6

V In

put

Gnd

+5V

+5V

D5

D4

D3

D2

D1

D0

(LSB

)

D 7 D 6

D 5

D 4

D 3

D 2

D 1

D 0

SHORTW IRE

B in a r y V o ltm e te r C a lib r a tio n C ir c u it

L EDs

0 to +5 V OL T S

BINA RY DISPL A Y

DMM


Task 2 – Calibration Circuit Breadboard


TrimPot• Total resistance (Pin 1 to Pin 3) = 10 kOhms• Resistance at Pin 2 varies by turning the small

adjustment screw (0 to +5V on Pin 2)• Use it to calibrate the Binary Voltmeter circuit• It is a variable resistor.

+5 V

1 0 K

P O T

13

2

Pins 1 2 3


8-Bit Binary Display• The LEDs at the output of the

Binary Voltmeter are labeled from D7 to D0

• The LEDs have two digital states, on and off, representing the binary numbers “1” and “0”

• D7 is the Most Significant Bit (MSB). D0 is the Least Significant Bit (LSB)

• The 8-bit binary number can be converted to a decimal number using a formula

D 7 D 6

D 5

D 4

D 3

D 2

D 1

D 0

8-BIT BINA RY DISPL A Y

L EDs

MSB LSB


The Decimal Equivalent of the Binary Number

•


Why use Binary Numbers?

• Binary numbers are used in almost all computers due to its use of digital electronic circuitry and logic gates.

• Numbers are written in a combination of bits.

• Counting in binary is straightforward.

P. 13


How does counting in Binary work?

• It works the same way that you have learned to count with Arabic numerals– Instead of 0-9, you now use only 0 & 1

• The pattern goes according to the following form: 8-Bit Binary

Number Decimal Equivalent

0000 0000 0 0000 0001 1 0000 0010 2 0000 0011 3 0000 0100 4 0000 0101 5 . . . . . . 1111 1110 254 1111 1111 255


8-bit Binary Numbers

00000101 = 5

LSBMSB

…. + 0*23 + 1*22 + 0*21 + 1*20

= 5

For example, convert binary 0 0 0 0 0 1 0 1 into a decimal:


More Examples

Binary Number

Decimal Equivalent

11 3

100 4

1101 13

111101 61

•


Task 2 – Finish building the Calibration Circuit

+5V

Gnd

Short wire

• Connect the Binary Voltmeter board to Gnd (orange wire)

• Place the TrimPot as shown and:• Connect Pin 1 to

Ground• Connect Pin 3 to

+5 Volts• Connect Pin 2 to

V Input on the Binary Voltmeter

• Connect the LEDs• Connect the Red

DMM wire to V Input


Task 2 – Calibrate the Binary Voltmeter CircuitTable A

Set Voltage Record Binary Numbers Calculate Decimal Values0 0 0 0 0 0 0 0 0 0

0.51.01.52.02.53.03.54.04.55.0

Full CW


Task 3 – Solar Energy Meter Schematic

+5 V +5 V+5 V

P C B 1

Light Se nsor

5

2 1

63 4

V O

ut

+5V

+5V

V O

ut

Gnd

Gnd

P C B 2

Binary Voltm e te r

6

2 1

75 14

4 3

8 9 10 11 12 13

D7

(MSB

)

+5V

+5V

D6

V In

put

Gnd

+5V

+5V

D5

D4

D3

D2

D1

D0

(LSB

)

D 7 D 6

D 5

D 4

D 3

D 2

D 1

D 0

BINA RY DISPL A Y

SHORTW IRE

S o la r E n e r g y M e te r C ir c u it

L EDs


Task 3 – Solar Energy Meter Breadboard


Task 3 – How the Light Sensor Works

• The Photodiode converts light photons to a current

• The Amplifier converts the current to a voltage

• The voltage output of the Light Sensor Board is proportional to the intensity of sunlight (Isolar, Watts / m2)

The calibration equation for the Solar Light Meter is:

Isolar = 5.0 Ndecimal (Watts / m2)

Isolar

AmplifierPhotodiode

V Output


Task 3 – Finish building the Solar Energy Meter

• Remove the TrimPot and its wires

• Plug in the Light Sensor Board (as shown)

• Add an orange ground wire

• Add a red wire from Vout to V Input


Task 4 – Use the Solar Energy Meter to measure the intensity of a light source

• Place the spotlight in the ring stand so that the front of the bulb is 13 inches away from the top of the Light Sensor.

• Make sure that the Photodiode is directly in the center of the beam.

• Measure the Intensity of the light source at distances of 23, 19, 15, 11 and 7 inches.


Task 5 – Measure the Intensity of the Light Source at various distances

Table B

Distance( Inches ) Binary Number Decimal Value Intensity

( Watts / m2)23.019.015.011.0

7.0

solar energy meter lab

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