Saturday, June 13, 2020

What Is Electrical Engineering?

Electrical Engineering

What Is Electrical Engineering?

Electrical Engineering is a very broad major that encompasses a lot of sub disciplines within the umbrella of Electrical Engineering, there are fields like RF which is basically wireless communications or you could work on satellite communications for defense purposes so the signal cannot be jammed by an enemy, there's electronics where you could design the circuit boards within computers or phones or the control systems within autonomous vehicles or the circuitry and a prosthetic arm there's power wheel you'd work with high voltage systems and delivering or generating lots of electric power that could include working at a power plant working with solar panels or something like electric motors and regenerative braking where like in certain electric vehicles when you take your foot off the accelerator the motor turns into a generator due to changing speeds of certain components within the system and then the kinetic energy of the wheels is used to generate electricity that can be stored for later use.


There's controls where you work on things that have some sort of electrical feedback like propulsion systems in various aircrafts all the way to your cruise control where your speed is monitored then depending on what it receives the system turns the wheels faster or slower accordingly which then affects your speed which is then fed back into the system and this control loop continues.


There's instrumentation which deals with designing sensors and equipment to measure physical quantities like pressure temperature motion position, and so on you can design motion detection sensors for a security system GPS for aircrafts or all the sensors in your car that to analyze fluid levels temperatures battery voltage anti-skid braking system or more advanced systems for driverless cars these types of electrical engineers often work with controls engineers because after all a controls engineer could design a great system to control the speed of an aircraft, let's say but if all the sensors cannot accurately determine the speed air pressure and so on the control system is basically no good there are many of these fields for the last one I'll explain .

Signal Processing

The signal processing this is simply about the manipulation and analysis of signals signals being essentially functions that convey some sort of information maybe you have this sinusoidal voltage at some frequency and then a sensor in the system causes an increase in the frequency, and that frequency change is related to the temperature that the sensor is picking up now that changing voltage or signal it contains information about the temperature in the room though we could convert to a text on a screen, let's say but when it comes to signals in general you might have to amplify them like for an earpiece or filter them where there's background noise and much more and this can apply to radio signals cell phone signals radar missile guidance systems speech image or video processing that all involve signals that need manipulation there's GPS signals noise cancelling headphones and of course way more okay now I've all right throw a lot at you to encompass a lot of what you can do as an electrical engineer and as you can see it's very broad it's not just one thing as in to people who majored in electrical engineering as with many other engineering disciplines could be in two totally different fields or careers and have very little knowledge about each other's work and this is also not about being an electrician by the way which is a common misconception electrical engineering is not where you go in and install or repair electrical systems in people's houses or in offices and so on but if you're debating picking this as a major all the fields I discussed could seem like a lot and you may be thinking wait what does an electrical engineering major look like and what can I expect, and that's will go into now while all schools are a little different a typical electrical engineering.


Curriculum consists of a few circuit analysis classes to just get you started digital design a Power Engineering class continuous-time signals and discrete-time signals which will get you started with analog and digital signal processing respectively you'll think of controls class a communications class which will learn the basics of FM and AM radio a basic electronics class which likely is followed by analog and digital electronics some electromagnetism courses which are basically physics classes and a microprocessor class there are some others you'll take and this doesn't cover the math or physics classes that you'll see but these are the big major classes, you'll take some classes on most of those sub disciplines I mentioned earlier you got your power class you got some signals classes wireless communications controls and so on as an undergrad you get exposure to a lot of foundations of Electrical Engineering and you become well-rounded but you don't become an expert in really any field that's where masters and PhDs come in or just simply working in a field for many years of course you will be taking electives in the subfields you're most interested in though towards the end of college so you will gain a little more mastery in those classes.

Circuit Analysis

The circuit analysis classes now if you've taken physics classes in high school, maybe you've seen the basics of resistors capacitors and inductors and you're going to learn how to find the voltage and current in circuits that contain these three components first starting off with just resistors though in the real world circuits are normally extremely complicated and engineers usually use software and simulations to analyze the circuit but in school you gotta learn the basics of voltage and current in a circuit for those who may be unfamiliar if you imagine a network of pipes you could use a pump that creates a pressure difference and causes water to flow around and through all the pipes if the pipes are skinny let's say it'd be harder for water to flow through them and if they're thicker that of course would be easier well in a circuit the voltage from maybe a battery is like the pressure difference from the pump the current or electron flow is like the water and the resistors are like the pipes high resistance is like a skinny pipe harder for water or the current to go through your electronics work for many reasons but mainly it's because electrons are flowing through the device in school we learned techniques to find the voltage difference across various resistors just like there'd be some pressure difference across each individual pipe circuits classes are a lot of systems of equations just like you learned in school, before but more variables usually instead of X and Y it's usually V and I for voltage and current and to begin all the circuits have a constant voltage as an input like a 9 volt battery that is not changing.

Capacitors and Inductors

Capacitors and inductors you'll use those same certain analysis techniques and the voltage source will still be constant like a battery but current and voltage in the circuit across those components change in an exponential way like charging up a capacitor to a max voltage in order to find that max value or the time it takes to charge up to let's say half the max value you will use circuit techniques to find the resistance in the circuit and so on then you'd quickly move on to AC circuits or alternating current where the input voltage is no longer constant but sinusoidal and changing over time for these circuits there's some more complexity added where a capacitor or inductor in a circuit with a resistor causes the voltage to change its amplitude but also shifts it the capacitor or inductor can change the phase of the voltage within the circuit the math behind this actually involves imaginary numbers that square root of negative one you learned in high school actually has a ton of applications and this is one and it's not because current or voltage are imaginary but using imaginary numbers just makes the math work when it comes to changing the phase or theta offset in a cosine or sine function don't worry about all that now, but it is something you will learn there's of course plenty more in the basic circuits classes.


The signals classes these are essentially math classes and will be one of the most math intensive electrical engineering classes you'll take before this you've dealt with constant voltages and then sinusoidal voltages but what about well everything else you would have a triangle wave a square wave or some really complicated and messy voltage which is what real-world signals can be like so what happens if you put a circuit well in first signals class, you'll learn something called the Fourier series and Fourier transform something very important in physics engineering and applied math this says that any function can be made up of a bunch of cosine and/or sine functions added up often an infinite amount we can see just a plain square wave but if you have a sine wave and add it to another and then another and you keep going picking sine waves to the right amplitude and frequency it will approach that square wave in this class.

You will use some calculus and some new math concepts to find those frequencies and amplitudes of the sine functions that make up some other function so now if we put a square wave into the circuit and want to know what the voltage and current will look like we can mathematically model it like putting in a bunch of sinusoidal waves of different amplitudes and frequencies which you will already have under your belt you'll learn lots of mathematical techniques to simplify this for you now two specific types of signals you see that kind of like sinusoidal but not really are AM and FM radio signals which brings us to your wireless communications course this class is not about physics but just more of the math behind specifically AM and FM signals if you look at a simple AM signal you'll notice the amplitude oscillates up and down and if look at an FM signal the frequency oscillator throughout the wave by making the signals look like this it causes the frequencies to move up to some specific unique center frequency like 94.1 megahertz that the radio station transmits at this is what the station 94.1 fm is just that station transmitting at that specific frequency yes it's more complicated but that's the general idea without that manipulation you could not wirelessly send those signals for people to listen to in their cars, you'll learn why this has to be done and all the math behind that in this class.


Will be pretty much all physics and involve a good amount of calculus you'll see how when you have a changing current it creates a magnetic field around it which then in turn creates an electric field around that and this continues in this propagates as an electromagnetic wave because it's electric and magnetic fields are coupled together you'll learn a lot about what those waves do when they interact with objects like what if they hit some metal barrier or they encounter water how far could they penetrate if there was a receiver at some depth you'll also learn about transmission lines which aren't probably what you think of the ones you learn in this class are cables that handle very high frequency signals that oscillate back and forth very quickly you cannot just put a very high frequency signal into a normal circuit issues come up simply due to the laws of physics and you'll learn about all that as well many of your other classes tell you about how to analyze signals and manipulate them various purposes but this class really teaches you about the physics of the waves so you can understand things like how our wireless signal will be affected as it travels through Earth's atmosphere when we have to communicate with a satellite for example.


You'll finally learn about the transistor there are billions of these in your laptop and millions in your phone to make them work there are lots of kinds of transistors but to simplify in a circuit the current often flows and of little flows and they combine and flow out, you'll learn more certain analysis techniques to analyze voltage and current in circuits as always but the thing is by changing this voltage on the transistor you can control how much current flows through the transistor meaning the transistor can essentially act as a switch it can allow current to flow which is basically like the transistor being on I think shut off curtain flow which is it being off of course this can create a high voltage like five bolts and change it to a low voltage like zero bolts this is the binary or ones and zeros that are really under the hood of your computer you will learn about making circuits that can switch quickly and efficiently in your digital electronics class analog electronics is more about using transistors to amplify a voltage which is their other main application where amplification would of course be needed for music or hearing aids as an example now.


you'll analyze electric motors and generators new circuit analysis with those you'll do labs where you work with much higher voltages than normal like over a hundred volts you'll see how much power is
dissipated and the resistor networks and so on and the controls classes do mainly with systems that involve some sort of feedback you'll look at things like stability because if you're constantly feeding information back into your system and something goes wrong it could continuously be maybe amplifying some output which will lead to issues you'll also see a lot of graphs where you have some target output signal and in some cases that are will be overshoot and then the signal will settle back to that target after certain amount of time versus just slowly charging up you'll mathematically find that overshoot how to minimize it or avoid it and more hopefully that gives you a good overview of the major.

If you want information on specific labs you'll do from freshman to senior year of college more specifics on the concentrations their applications and previous senior projects what math classes you'll take and how my first job or internship was,  this was a good foundation some schools especially outside the US it seems like offer majors in electronics engineering or telecommunications engineering, lastly as you can see Electrical Engineering can get you jobs in the aerospace field biomedical field that tech companies defense companies in the energy sector and robotics and so much more but so can plenty of other engineering disciplines that are also broad so if you're considering this major make sure this is the type of engineering you want to do specifically when it comes to whatever field or sector you may want to go into.

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