Optical Sensor for Noise Flickering

Group Members

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

Set-Up

Equipment Needed

• Soldering Iron
• Soldering Tin
• Shrink Tubes
• Wires
• Resistors: 10k, 100k, 500k, 1M, 10M
• LDR Photoresistor: GL5528 / GL5537
• DC Power Supply (Matrix MPS-3005L-3)
• Signal Generator (Agilent 33220A)
• 40 MHz Analog Oscilloscope (Hameg HM400)

Experimental Set-up

Circuit design concept

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

Timeline

Week 8 (11 - 15 Mar)	Complete circuit set-up on PCB 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