This project was proposed. Is basic principles of signal transmission through a fiber obtic in a simple and saves.
A simple communication systems to home use. Video Door Phone Intercom is going to happen in the future. or Meetings monitor route. via the computer network with Electromagnetic wave Or transmitting visual information, audio and more. By is connected through a Conductive metal wire or electromagnetic waves. It’s complicated. And not very effective. We so find another intermediary, so found that the light can lead them to the same destination. Without distortion at all.
The working principle.
In figure 1 The circuit is divided as 2 main section are transmitter and receiver.
– The receiver consists of 3 parts are : 1. the signal receiver 2. the amplifier and 3. the converter.
– The transmitter, A MIC1 act as the sound receiver once we talk to a microphone, the voice is converted to the electrical signal.
Next wire connected to a capacitor C1 smooth a fluctuating signal. To bias a transistor Q1, but the signal get from the output of Q1(2SC1815) still not heavy enough so must increase up by the Q2(2SC1815).
And then the signal is sent to the MFOE76 photo diode. To convert electrical signals into optical signals. It is a red light that we can see.
Figure 1 Diy fiber optic intercom circuits
On the receiver section, the MFOD73 photo transistor act get the optical signals from the transmitter by through the fiber optic wire, then the optical signals is converted to electrical to bias with the Q3(2SC1815). But the signalHowever, the signals have very low the voltage. Not enough to drive the speakers. must using IC LM386N amplifier to increase up the signal strength. The VR1 is adjusted with the strength of the signal.
How to assemble circuit
Due to both the transmitter and receiver circuits are separated from each other. We need to create two unit are one transmitter and one receiver unit. Each device will use battery 9 volts is the applied a voltage to the circuit.
First, make PCB is 2 sheets. Characteristics copper pattern shown in Figure 2. When it comes to printed circuit boards. The soldering equipment. According to Figure 3. Be careful leg devices, transistors, ICs, capacitors, must enter it correctly. Then solder the wires to the external device attached to the box. on the prototype use the versatile box. Which can be mounted PCB to fitted.
Figure 2 Diy fiber optic intercom PCB.
We can use it as a general intercom. However, because this project is a one-way intercom. Can send audio signal only. And that’s important. Using a fiber optic transmission. Should be careful not to make the twisted fibers within it may be broken.And should not be Using too long. Because it is implemented in a simple way. No repeater station.In an experiment at a distance of 14 feet the sound quality is also good. So it may be Using fiber optic cable was longer. Applications may be used as a tool for communication between one room to another room that was around the same time.
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