Solar Energy Labs – Part 1 ENGR 1181

Today's Learning Objectives  After today's class, students will be able to: Describe and build both a calibration and solar meter circuit Convert decimal values to binary values Discuss how a potentiometer works Explain how a photodiode light sensor works Compare a pictorial image of a circuit to a schematic wiring diagram Use a Photodiode Light Sensor and a Binary Voltmeter circuit to measure the intensity of light (in Watts/m 2 )

Solar Energy Meter In lab today, you will build a solar energy meter circuit to measure the energy intensity from a light source. solar energy meter Output : watts/m 2

Solar Energy Meter Parts  5 Volt power supply  DMM  Breadboard

Solar Energy Meter Circuit Schematic and Breadboard Layout – Final Circuit

Breadboard Setup Build now in pairs! Measure the Power Supply Voltage, V = ______ Volts +5V Gnd Note DMM usage here Note jumpers

Calibrate the Binary Voltmeter

TrimPot – varies input voltage  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 change the input voltage to the Binary Voltmeter circuit  It is a variable resistor. 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 MSB LSB

8-bit Binary Numbers = 5 LSB MSB …. + 0* * * *2 0 = 5 For example, convert binary into a decimal:

The Calibration Circuit +5V Gnd Short wire of LEDs must be toward ground side 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

ENGR 1181 First-Year Engineering Program Calibrate the Binary Voltmeter Circuit Table A – record and store in lab spreadsheet Set VoltageRecord Binary NumbersCalculate Decimal Values Full CW

Solar Energy Meter Circuit Schematic and Layout

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 (I solar, Watts / m 2 ) The calibration equation for the Solar Light Meter is: I solar = 5.0 N decimal (Watts / m 2 ) I solar Amplifier Photodiode V Output

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. Comment on shading LEDS and Blinking on least significant digits

ENGR 1181 First-Year Engineering Program Measure the Intensity of the Light Source at various distances Distance ( Inches ) Binary NumberDecimal Value Intensity ( Watts / m 2 )

TopicDocument Type Marble Delivery SystemNone Quality and ProductivityExecutive Summary CircuitsExecutive Summary Solar Energy – Part 1-- Solar Energy – Part 2Memo (Combined) Beam BendingMemo Wind Turbine 1-- Wind Turbine 2Report (Combined) Problem Solving Project 1 Project Notebook (Combined) Problem Solving Project 2 Problem Solving Project 3