Optical Sensor for Noise Flickering

Group Members

Eric Cheung Jun Hao; Lee An Min, Amanda; Loh Jia Ying Whitney

Set-Up

Equipment Needed

S/N	Item	Description/Model No.
1	Soldering Iron	-
2	Soldering Tin	-
3	Wires	-
4	Resistors	10k, 100k, 500k, 1M, 10M
5	LDR Photoresistor	GL5528 / GL5537
6	DC Power Supply	Matrix MPS-3005L-3
7	Signal Generator	Agilent 33220A
8	40 MHz Analog Oscilloscope	Hameg HM400

LED S/N	Colour	Wavelength (nm)	Size (mm)
1	Red	643	5
2	Orange	625	5
3	Amber	605	5
4	Green	570	5
5	Blue	-	5
6	Red	650	3
7	Orange	625	3
8	Green	570	3
9	Blue	-	3

Experimental Set-up

Circuit Design

The circuit consists of a simple potential divider, with a resistor and a photodiode. By exposing the photodiode to visual noise tags, such as the flickering of LEDs, the output voltage. The photodiode resistance is a function of light exposure. The resistance is reciprocally proportional to light intensity. The output can be observed on an oscilloscope to determine the performance of the photodiode.

Variables

The performance of the photodiode will be determined by varying the following parameters: 1. Wavelength of LED 2. Resistor in circuit 3. Frequency of blinking (1Hz - 100kHz)

The dependent variables that will be measured are: 1.

This will allow us to determine the following parameters: 1. Efficiency (Time decay) of photodiode at different wavelengths

Timeline and Milestone

Week	Dates	Tasks
Week 7	4 - 8 Mar	Collecting equipment and prelimary set-up
Week 8	11 - 15 Mar	Complete circuit set-up and prelimary measurements
Week 9	18 - 22 Mar	Data collection (vary LEDs)
Week 10	25 - 29 Mar [Well-being day (28 Mar), Good Friday (29 Mar)]	Data collection (vary resistance)
Week 11	1 - 5 Apr	Data Analysis and further measurements (if needed)
Week 12	8 - 12 Apr [Hari Raya (10 Apr)]	Data Analysis and explore other light sources (phone/computer screens)
Week 13	15 - 19 Apr	Analyse experimental results and complete documentation