₦airaland Forum

doghorp:
Good nairaland group
I have always want to learn more about Automation. I have HND Mechanical Engineering Bsc Physics and I want to do a masters Degree Instrumentation and Control Engineering. Good group to learn from

You are in the right place

Southboy:


Are the following statements accurate?

1. Electric charge is produced when voltage pass through a capacitor.
2. Magnetic field is produced when current flows through an inductor.
If these statements hold true,
3. Is this the sole method for generating electric charge and magnetic fields?

Don't confuse charge and field, they are two different things.
Go back to Faraday's laws on electricity generation.
Inside electronics,
Voltage is the only source of electric field
While current is the only source of magnetic field.
There is nothing outside
a. Voltage
b. Current
c. Load (Resistance)
In a circuit. Remember Ohms law.
Every other variant like Frequency, power factor etc is explaining voltage, current and resistance

Southboy:


Are the following statements accurate?

1. Electric charge is produced when voltage pass through a capacitor.
2. Magnetic field is produced when current flows through an inductor.
If these statements hold true,
3. Is this the sole method for generating electric charge and magnetic fields?

You still need to get this clear. Am going to open a thread on Career in Electronics. I will explain capacitor in more detailed form. I said it earlier that capacitor is a mini battery.
Now let's explain voltage. Capacitor/ battery is a source of voltage. Voltage does not pass through a capacitor but is established across the two terminals.
Battery is a source of EMF - Electromotive force meaning force that set electrons in motion. Voltage is a potential difference between two point which is the same meaning as EMF.
Let's explain what it means by difference in potential.
Get a 12 by 1 inches plank( wood), at the two ends mark point A and point B. Put the ball at point A, the ball remains there. Remove the ball and put at point B, the ball remains there.
Question:
Why didn't the ball move from point A to B?
Answer:
It's because point A and point B are at the same level (Potential)
Now, slant the wood to an angle say like 60 degree. Point A at the top, point B at the bottom, point A is no more on the ground level as before (higher potential), point B still remains at the bottom level ( lower potential).
You can see that you have succeeded in creating a potential difference between point A and point B.
Put the ball at point A and observe what happen, you will see that the ball moves from point A to point B just because there is a potential difference.
In battery/ capacitor, point A and point B represent the positive and the negative terminals. Both are at different potentials. The ball represents the electron. The force that caused the electron to move (EMF) is the voltage.
Voltage is the source of force that drive electron in motion within a circuit. The flow of electron produces CURRENT though in opposite direction.
Hope I have not confused anybody

@Southboy, a very good attempt. Keep it up.
I want to make one point clear. We have two energy storing systems
a. Capacitive
b. Inductive
Capacitive systems store energy in electric field
Inductive systems store energy in magnetic field
Battery belongs to capacitive systems, hence have no business with magnetic field
In a circuit that integrate capacitor and inductor, we have the combination of the two field. - Electromagnetic field.

More input brings more clarification. Let everybody get involved. Kudos @Southboy

Happy Sunday to all
Am very happy with the response from our class rep(Southboy). The answer brought out the exact information that I needed.
It's good to have a good understanding of something. All my write up here are not copied from any note or book but directly from my head. Let's us have a deeper understanding of whatever we discuss here for future sake.

It's now very clear that the nature of magnetic field produced from AC and DC current are different. One is building and collapsing while the other is stable.

Another question that will earn you #200 recharge card from me is this:
What's the application of magnetic field produced from
a. AC current
b. DC current.

Please everybody get involved. That's sure way of knowing it deep

[quote author=Southboy post=125224495][/quote]Very good answer

Let's consider the type of magnetic field produced by
a. AC current
b. DC current
And their applications.
Because ac current is changing ( positive and negative half cycle), you have a magnetic field that builds up and collapses
On the other hand, since DC current is not changing, the field produced is fairly constant, does not collapse until the current is removed

In a normal life, you cannot separate fire and smoke. Fire produces smoke. So also smoke produces fire.

Same way, you cannot separate electric current from magnetic field. Whenever there is flow of electric current on a conductor (Inductor), magnetic field is produced.
Also, whenever there is changing magnetic field, an electric current is produced.
Any confusion at this point?

I appreciate your input @Newusername.
Where is my class rep(southboy) and others?
Waiting for your contributions

We are going to discuss inductor base on the two pictures below. That's after my questions are answered or attempted.

Still waiting for answer to my question about an Inductor.

janga02:
Well done boss,

Thank you for this mentorship class, I hope students and young grad will take advantage of this class seriously because, what he is trying to dish out to you free of charge here, somebody spent #800,000 to 1 million to get this from an institute.


I am an electrical engineer by the way and I know what it's like to be a resource person in a department.

Hopefully, I would be able to contribute to this as the class progress.

Kudos to Oga "ytdivine"

Thanks for the compliment. I said it before that young graduates and students will not appreciate this golden opportunity. Its only those working in industries that knows the value.
This is my own contribution to national development

What do you know about an inductor. What happens when
a. ac current
b. DC current
Passes through it

Rome was not built in a day. A journey of 1 mile begins with a step. This journey of skill acquisition is a gradual one. Get serious with it. Little by little, you're there

Newusername:
Good evening boss. It's not like that oo. I have been busy. I will be doing all your assignment tomorrow.

You're forgiven but make sure you participate very well

Southboy:
If I get you correctly, electric signal is used to charge the capacitor?
Can the device work when the capacitor is not fully charged?

Yes it works, take for example, your LED touch, the moment you on it, it turns on but fades gradually when turns off. The delay is visibly observed in discharging and not during the charging phase

The next component which is the foundation of our programming is
INDUCTOR.
Our PLC programming language is Ladder Logic Language. This language is based on Relay Logic. Relay is based on Inductor. So pay maximum attention here.
What is PLC?
During interview season, you get amazed by response from job seekers.
There is a computer that control all industrial activities. This computer is called PLC, meaning programmable Logic Controller.
In advance electronics, you talk about Microprocessor and his elder brother, microcontroller. From this, you get Controller (computer). The one you can program or manipulate a lot is PLC.
Hope the point is clear

Practical class number 2 is capacitor.
Note it.

Capacitor is a voltage source
Inductor is a current source
Capacitor produces electric field
Inductor produces magnetic field
Note these points very well.
You can't know electronics without a deep knowledge of capacitor. Good understanding of capacitor alone can put food on your table. Am not going into capacitor in details but it's a component you cannot do without in this field of automation.
To excellent in this field like any other engineering field, you most be good in electronics, the mother of engineering.
We shall deal more on capacitor during the second practical class.

In the above example, we dealt with water flow, let's consider signal flow in a circuit.
Do you know that motion in a television is a multiple of images(continuous image flow). What happen when the motion is fluctuating? Do you know the source of our power supply (NEPA) fluctuates like the water flow from the pump. If this happens, you find out that the images from your TV set keep dancing and in S-Shape form. This is a practical illustration which you may have noticed.
Television is used here for example, this is the case for all the electronics.

Capacitor is a storage tank ( buffer) that stores electric charges(water) in an electric field(water pool/swimming pool)

The following should be noted
a. Charging and discharching (filling and offloading tank)
b. Energy storage (water storage)
c. Source of electric field ( water pool).

So when an electric signal passes through a capacitor, it absorbs the signal until its full and now acts like a new supply source providing a better signal flow(filtered signal). Capacitor is a mini battery in a circuit.

I hope I have not confuse anybody

Moving forward, let's explain what happened in this water supply scenario
In the case of pumping water direct to the tank without a buffer tank, note the following
1. Fluctuations in the water supply due to pump operation is transmitted to each flat ( No constant flow)
2. There is no pool of water created
3. Water distribution is not uniform
4. The moment the pump stops, the flow stops
Looking at the second scenario, the following is obtainable
1. Because there is overhead reserve, there is no fluctuations in the water flow
2. A big pool of water is created
3. The distribution is uniform
4. Continuous water flow even when the pump stops until the whole stored water is discharged.

Please any objections to these assertions?

Kingslaw:
good morning Sir, been busy with my clearance so that I can go for service next month. I will be checking on every morning.

Best of luck.
Good footing

As a punishment for not doing my assignment, the following students should come to the front of the class and kneel down
Zealousayo, bestbiz17, eddyboy, new username, micros
You can stand up and get to your seat once you do your assignment.

I want to make it clear here to young graduates, you have to pursue knowledge with your strength. Don't Wait for it to be served to you.
In 2008 when I was doing my Master in control Engineering, University of Ilorin, our HOD then prof. Ibiyemi will issue you course outline and ask you to provide the materials by yourself. He may have two or three contacts with you if you're lucky before the exam.

My major mentor in this field, a polish man, Mr Arik, does not speak English very well, cut and join English, whenever I ask him certain questions, he will refer me to machine manual. These are things that you may never understand even when read several time except knowledgeable person explains it to you.
Do you know what my mentor will ask me?
He will ask, what language is the book written? I will answer English. Then, the next thing, you understand English more than me. Eventually, I will be the one that provided answer to my question.
Friends, don't be lazy, work out your salvation with fear and trembling. That's the Bible for you

Let's move ahead.
Many of us live in a flat were borehole or well water supply is available to everyone via good water supply network courtesy of Plumber.
Let's consider two scenario
1. Situation where there is no overhead tank, water flows directly from the pump to about 4 block flats
2. Overhead tank is mounted and water is distributed to each flat via the tank.

Let's discuss again, I want an active participation.
Want happen in each of the scenario?
How does each flat enjoy or receive water?

zealousayo:
We should not be selfish. I have learnt many things from threads made as far back as 2008. The forum should be information and knowledge bank. That even in many years to come, people can still benefit from it.

The suggestion was made because people were not responding. We want a very active class

Southboy:
Today is dull ooooo

Yes, not my fault. When people respond to my question, it shows am not dealing with ghost hence more energy for me to dish out information.
I have made myself available, people should draw as much knowledge as possible from my over 15years hand on the job industrial experience

I need more response. Others should respond as well

To continue, let's do little exercise,
What do you understand about a capacitor?

bestbiz17:
Alright sir, I am following your lead. And I want to ask that is there any option for internship for a undergraduate since schools are on holiday?

Not yet

As we go on in this lesson, I will be tracking down some practicals to be performed
Number 1
How to measure
a. 24vdc
b. 0 - 10 v
c. 4 - 20mA
This is one of the job interview practicals.

Let's take a step further, these signals are used in control functions. Very soon, we shall look at control.
Electrical or electronics systems are built or designed to allow various electrical signals to pass through them. In electronics, there are small small components that makes up the electronics units. Each components behaves differently when these signals pass through them.
Let's take this illustration.
Consider three men
Mr A
Mr B
Mr C
Let's simulate them with a slap (Signal)
You will find out that each of them react differently.
Reactions
Mr A : May God bless you
Mr B: a doubled returned slap
Mr C: collapsed
You can see from this illustration that the responses are different even though there were all subjected to the same input signal ( slap)
In engineering, we call it transfer function.
This is another foundation, if we get this point very clear, we will not have problem understanding relay logic which will eventually transform to Ladder Logic.
We shall consider two energy storing electronics components and see how they respond to electrical signal
a. Capacitor
b. Inductor