“Final Design project Paper”
By: Alfonso Raymundo & Can Liang
Alfonso Raymundo
Can Liang
E E 230
Final Design project
December 10, 2012
Final Design project
Introduction
The goal of this lab is to build a simple build a simple optical signaling device that lights
a red LED when one button is pushed and green LED when another button is pushed.
Experiment 1 - Building the circuit
The first thing they did was Google transmitter low freq. That way we know what to
build real to build a high pass filter which is shown below in the picture. Just so I can simplify
the report better I will provide images of our circuits shown below with colored boxes that
explain what they are and what they do and don't talk about them in my report later on.
The first part of our circuit is the 2K Oscillator & 9K Oscillator. An Oscillator is an
electronic circuit that produces a repetitive often a sine wave or a square wave. We use these
oscillators to produce the right frequency we needed that way just by switching oscillators we
will have different frequencies. Images of the frequency and sideways from these oscillators are
shown below.
project_01_transmitter_low_freq
project_02_transmitter_high_freq
The second part circuit is the receiver and also the multiplier. The resistor is supposed to
receive the signal from the infrared LED which is found on the Switch & Transmitter circuit.
The multiplier is supposed to convert the current has been received into voltage. Images of our
voltage from the high and low filter are shown below.
project_03_receiver_low_pass
project_04_receiver_high_pass
The third part of the circuit is the rectifier. A rectifier is an electrical device that converts
alternating current (AC) to direct current (DC), the reason we decide to use a rectifier if so we
always have a constant supply of direct current now with the LED stays lit as a blink on and off
very fast. Here are our waves from a rectifier after we finished building them.
Project_05_receiver_rectifier_2khz
Project_06_receiver_rectifier_9kHz
The final part of our circuit is the peak detector. A peak detector is used to keep the peak
voltage level of a any type of wave. A partially for this part we were not able to get it to work
completely so we got zero voltages from the output voltage of the peak detector. Images of our
work are shown below.
Project_07_receiver_peak_detector_2kHz
Project_08_receiver_peak_detector_9kHz
Conclusion
After finishing the final project I realize we were unable to get the LED to light because
the peak detector was unable to keep the voltage at the high point we needed so we can have
a constant voltage going into the LED. I myself believe the reason we were not able to get
any voltage was because we probably designed to be detector too well and it refused to allow
any voltage to go through it and lets it was really high voltage. We also have a trouble with
our multiplier because our multiplier refused to work when it was put together with the rest
of the circuit but individually we got it to work.