Saudi Arabia College of Engineering King Saud University Electrical Engineering Department Applying the LED System instead of the RFID system in transportation’s toll. EE-411 Optoelectronic Systems and Devices 2009-2010 (2nd Semester) Dr. HabibFathallah Dr. NacerDebbar By: Ahmad Hani Ismail –42710173 Mohammed Al-Masoudy– 425113782
The principle of the Optoelectronic System in the Television Remote Control The Circuit Board of the Television Remote Control LED Description LED as Sensor Comparison between RFID system and LED system
Parameters and calculations for the System Distance Wavelength, Frequency and Photon Energy Divergence & Intensity & Power LED Driver circuit LED photo-receiver drive circuit Programming Code
What is theapplication of the (RFID System) which is already existed? Introduction
RFID (radio frequency identification) Salik was already applied In Dubai City in toll gates of 4 different places in the city.
Its purpose is not to effect impact to traffic flow.
It allows vehicles to move freely through the tolling point at highway speeds without stopping.
1.2.3 LED As Sensors A LED light sensor is a Light-Emitting Diode used as a photodiode, But it is biased in reverse voltage, and it work as current source. (look at Figure down)
Comparison between RFID system and LED system 1.2.4
Chapter Two Parameters and calculations for the System. 2.1
We're going to determine the parameters for the components of our new LED system by calculations and formulas, which are:
Distance Wavelength, Frequency and Photon Energy Divergence & Intensity & Power
Distance 2.1.1 Distance between LED transmitter and Photo-Receiver was assumedto be 5 meters. 5 m.
Wavelength, Frequency and Photon Energy 2.1.2 We studied that we can determine all of the wavelength, frequency and photon energy by a given Figure to be determined and known as standards. (Look at the Figure) From the figure above we find that Infrared has a frequency of , wavelength of and energy of .
Divergence & Intensity 2.1.3 Wavefronts of a Gaussian light beam. Light intensity across beam cross section. (c) Light irradiance (intensity) vs. adial distance r from beam axis (z).
The beam diameter 2wincreases linearly with distance z making an angle 2θ at O
Divergence & Intensity 2.1.3 [we assume it is 0.5 mm]
Divergence & Intensity 2.1.3 By Fethagorse we find (X) which is in the cross section of the beam at receiving. . . X = 3.18 cm (Cross section area of the beam at receiver in at distance 5m )= X * 2 = 3.18cm*2 =6.36 cm .
Divergence & Intensity 2.1.3 Due to the divergence we found, we come up with some designing issue like the ability of detecting the LED Beam even in the worst cases of weather or temperature. We started a designing the photo-receiver by designing a system with one LED Photo-receiver as shown in Figure below.
Divergence & Intensity 2.1.3 After the previous design we considered the divergence and the attenuation of the air medium, We suggested that we better put many photo-receiver instead of one so it can receive the beam in different photo-receivers then it can be gathered in the end as one code.
Divergence & Intensity 2.1.3 And then we thought of developing the system to make it work in more effective way to receive all beams heading toward all directions by creating conditions most suited. We applied a Photo-receiver in the right and the left side of thePassageway, also we used a kind of medium which is suitable to reflect any beam heading toward the two sides of the passageway so we applied a surface of medium such as mirror on the two sides of the passage way. As in Figure.
LED driver circuit. 2.2 This is the components and its details that can be determined due to the parameters and the calculations, the circuit is as shown in Figure: -For the previous circuit the manufacture has determined that: Minimum input voltage for 1 LED : 5VAC The evaluation board is designed to display the full functionality as a LED driver to drive 1W at 12Vac input. Based on this circuit, there are nine different configurations with different input voltages and output power levels that could be derived by making minor components changes to the evaluation board.
LED Photo-receiver drive circuit 2.3 This is an example of the photo-receiver drive circuit that takes advantage of the photo-voltaic voltage of an ordinary LED. The LED voltage is buffered by a junction FET transistor and then applied to the inverting input of an op-amp with a gain of about 20. This produces a change of about 5 volts.
Each vehicle must have a different code that can be determined as pulses and this should be done by programming codes due to the transmitter and receiver ships inside the LED drive circuit and LED photo-receiver.
The LED drive circuit can be contains of PCI Controller or 555 ship to generate LED beam with pulses and we applied the PCI controller because the 555 need more programming than the PCI which is better.
Conclusion: The principle of our new optoelectronic system has the same principle of the applications of the LED system in Television remote control. LEDs can have a relatively long useful life. It can estimate 35,000 to 50,000 hours of useful life, which means up to 6 years, though time to complete failure may be longer. LED less harming for humans and will decrease the danger of radiations in the RFID system. The LED drive circuit can be contains of PCI Controller or 555 ship to generate LED beam with pulses, and we applied the PCI controller.
Light Emitting Diode (LED) consists of a chip of semiconducting material doped with impurities to create a p-n junction. The principle of our new optoelectronic system has the same principle of the applications of the LED system in Television remote control. Each vehicle will have its own coding just like the coding in the television remote control. We are studying the system to develop a successful LED optoelectronic system so it can be used instead of the RFID system in Toll gates for transportation. We design the system of the LED regarding to our calculations of distance, wavelength, divergence, frequency, and power. Due to the distance, we can determine the power needed with regard to that the photo-receiver sensor must have properties that allow receiving a determined power. Conclusion:
Development: We Can develop our LED System and apply a small Solar-cell part instead of car Battery. That would : 1- Save power in car’s Battery 2- Make LED life longer
Development: We Can connect our LED system with the car’s system so the code can contain information such as some more information about how many Kilometers the vehicle has go and what is the speed of the car and that must be connected with the car’s system of Speed and the Meter’s counter. This would :
help the Government in statistics and other services existing in Saudi (Saher) system, and can be an alternative.
Applying the LED System instead of the RFID system in transportation’s toll. The END Thank You! Ahmad Hani Ismail & Mohammed Al-Masoudy Email: email@example.com & firstname.lastname@example.org