ELECTRICAL
Projects
Safety first!
Never take unnecessary risks!
Do not try experiments at home!
Call an expert if you are not qualified!
How did I build Electrical knowledge?
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About 15 years ago, I built a closer friendship with electricity only for my own purposes, but so to say, the beginning was not a super easy period. I indeed studied physics at a higher level in high school, I mean in a separate faculty group of physics, and in addition, I have regularly participated in physics-related competitions, mostly with pretty good results, plus a little later, I did tons of exams in electrical engineering subjects at the university, but despite all this, my experience was not too much in the field of practice.
So, I was aware of the scientific details of electricity already relatively early, but I gathered most of the practical knowledge little by little at home. At first, I tried to solve the less serious non-high-current challenges alone with more or less success, and after a few years of practice, I was able to solve the more complex issues that required much deeper knowledge.
Of course, I needed strong perseverance because I restarted this rather dangerous profession multiple times from different aspects. I quickly learned that the first step is to accumulate reliable experience, and only then can I move on to complex issues.
As far as practical knowledge is concerned, I would like to give some more specific examples. I started my electronics career with those classic DIP, TO-3, TO-220, and TO-247 through-hole style electronic components, where the pin spacing was only 2.54 mm. I soldered mainly these types of integrated circuit elements as different kinds of operational amplifiers, 555 timer ICs, power or switching transistors, or thyristors. Let me note that even though these types of through-the-hole packaging are considered quite outdated compared to SMDs, there are still many devices that can be built from them.
Nowadays, the users are very pampered because everyone prefers to use the ready-made goal-oriented modules, as they are available very cheaply for almost a few jacket buttons. Anyway, I also have some storage boxes full of gadgets like this since a lot of issues can be solved by them with minimal creativity. So, these panels have incredibly huge benefits because I can save a lot of time, effort, and raw materials, and in addition, much more serious things can be built from them.
Obviously, without confidence and strongly grounded knowledge isn't worth playing with any AC 230 V devices because this kind of super reliable experience requires a few years of deep practice, of course, beyond the appropriate qualifications. What’s more, officially, electrical appliances can only be repaired by a qualified electrician in any country in the world.
As I pointed out above, a master’s degree certificate provides only a scientific approach, without too much experience, since the acquired practical routine expands nicely step by step over time.
So, I would say briefly that keep gathering information from various trusted sources, and try to put them into practice, of course, according to your current level of knowledge, if you start your electronics career alone as I did 15 years ago.
Of course, I also made many mistakes in this learning process, from which I gained almost the best experiences, and I still have enough room for improvement. This is a very powerful method that primarily requires patience, self-confidence, and a lot of effort.
As a consequence of all of this, the problem-solving attitude is a learnable skill because all it takes is only motivation and enough commitment.
Of course, in the field of electronics, I always have to be extremely precise to avoid unexpected inconveniences and accidents, and in addition, I can only move within fairly strict limits because everything is based on facts, calculations, and measurements in this area. Especially the design and construction phases require a high degree of precision, thoroughness, and a so-called system approach skill to avoid problems that may arise later. It is enough to think only of properly sized active or passive cooling or the crucial touch protection standards, or even frictional insulation wear due to resonance.
Physics of Electric Current
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Let me say a few sentences about electricity. In my experience, many people would be confused only by the sight of the colored cables, and hearing the 50 Hz noise of a standard electricity meter - which can be found in every household - the majority would rather step back two.
This is very understandable and completely okay because this mostly invisible friend can be very dangerous and can easily surprise - a little tiredness and inattention is enough - even the most experienced professionals too. I also burned myself accidentally a few times by AC 230 V, especially in the beginning.
The electric current can be regulated very nicely if we know its natural behavior. The current consumption is consumer dependent and it always flows under the influence of voltage. So the current flows in the conductor, and the voltage is measured between two examined points and as a result of the potential difference, can begin the electric current to flow. In the case of constant current, the amount of charge (Q) flowing through the cross-section of the conductor during the unit of time (t) is called the strength of electric current (I).
I = Q / t
Let me mention here a particularly interesting property of the physics of electron flow, which is related essentially to the construction of different types of wires. It may be surprising, but the electrical charge density in a given conductor wire does not show a homogeneous distribution.
The point is that if we take a given wire cross-section, we can see that the electrical charge density within the wire is essentially zero, and it follows briefly that the free charge flow is at the surface of the wire. So this is the reason why most electrical wires are twisted, as they have a significantly larger surface this way than fully solid types with the same cross-section.
Electric current is present everywhere in nature from the smallest to the largest dimensions.
I have just said everywhere because according to the rules of physics, strictly speaking, there is no perfect insulator in the world, and it follows that everything can conduct electricity, even if only to a very small extent.
If I remember well, the electrical signal of a very small fraction of nano Amperes can usually run between the nerve cells at a voltage of a few tenths of a millivolt, but a flash of healthy lightning usually begins to flow from a few tens of thousands of Amperes even to hundreds of thousands of Amperes at a voltage of hundreds of thousands of volts. Let’s stop here for a bit because I didn’t accidentally write the former formula.
I calculated several times already in high school that despite the enormous current and voltage of lightning, its electric charge is actually very small, and that’s the point because even if we could use it, we wouldn’t go too far only with 1 piece of powerful lightning.
So in a normal situation, the lightning lasts only a few thousandths of a second, but our eyes see it much longer. To make it even more illustrative, I took a high-resolution fine-textured photo of the discharge channel of an electric arc and its light distribution. Just to make the picture even more accurate, I triggered here a 12000 V discharge only with 6 J of energy.
Let's suppose we have a more serious 1/1000 sec lightning with a powerful 50 000 Amperes and 400 000 volts. Anyway, in its main branch, it has such a thick discharge channel that it can be well over a meter.
Q = I * t = 50 kA * 1/1000 sec = 50 C
Then, according to my calculation, this tremendously large lightning has only a charge of 50 C.
Well that's not much. I calculated its electrical energy to be around 20 MJ, and 1 kWh = 1000 W * 3600 sec = 3,6 MJ, so it means only 5.5556 kWh.
In summary, the 20000 MW power of lightning is enormous, but its electrical energy is very small due to the shortness of time. So to make this surprising result a little more clear, using a 100 W lamp for exactly ten hours is equivalent to 1 kWh. :)
Moreover, I would like to note here that the awful strong electric car charging poles - compared to the household power - even with the general 50 kW electric power are slowly becoming small, because I recently read about the introduction of the 120 kW chargers, but we don't even have to go that far because a simple toaster with its 1,3 kW power can be an enough serious Ampere consumer on the kitchen table too.
Of course, if we would examine the exact process of lightning at a much higher level, then this electric discharge would be not just an almost constant signal, but there would be shock waves of both current and voltage components, which have up and down phases with appropriate peak and average values, and last but not least with corresponding peak and half value times.
Furthermore, I would also take into account the resistance of the atmosphere (~ 15-20 Ohm) for the given length. Moreover, at an even higher level, the current density distribution can be examined and calculated separately in the main and side branches of the spark channel too.
So, it can be seen, the study of electric current can also be cultivated at a much deeper level.
Know-how = Competence
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I believe that the acquired practical knowledge - the real know-how - has the greatest weight in the Market. This is exponentially true in the electronics sector, which is improving awful fast, and it is especially worth keeping up with technical innovations, even if it means sometimes a serious challenge. Fortunately, many branches of electricity can be cultivated very deeply, even at home too. From the initial design steps to the production of the printed circuit boards, there is a pretty smart solution for almost everything, of course, according to the needs.
Electricity can be found in almost every single device, but there are certain topics I especially like. I'm interested in microelectronics, vehicle electronics, and high current topics as well, such as:
​​- Power supplies
- Electric motors
- Battery chargers
- Measuring instruments
- Alternators and stators
- Engine speed control circuits
- Temperature regulating circuits
- Repair of vehicle electronic components
- Installation of vehicle electronic accessories
There are even further plans in my task queue, such as inverter electronics or MPPT and PWM chargers for solar panels, but I would like to learn about transformer and motor winding too.
Anyway, I recently tasted the last type of activity because I built a winding machine. I wound up mainly high-frequency transformers, but due to frequent air gap losses, I abandoned this line for an indefinite amount of time.
My custom solutions are mostly result-oriented and not profit-based because they are prepared only for individual needs. These are not the most beautiful tools and they are made not for the shelves in the shop window of today’s stores, but the devices I have built so far have done their job almost failure-free, and that’s the point that is important to me.
I think that's the best thing when creativity is limited only by time and money.
Mistake => Experience => Knowledge?
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Making mistakes is a natural part of every process. The only question is whether we can convert the experience gained in this way into knowledge.
I find that seemingly contradictory regularity interesting that almost the most valuable knowledge usually comes from mistakes. It is true that in the field of electronics, this can be quite a sensitive factor, as an unexpected mistake can even lead easily to serious accidents, but of course, I didn't think of them right now.
In my experience, the less successful projects, except for the most critical cases, can often be used to gain particularly valuable knowledge. This fact is not always super clear to understand immediately, especially in the case of costly failures, but it still works, even though we don’t pay enough attention to it.
So the experiences are accumulating continuously, which should be constantly filtered only for the best solutions. I would say that it is also a kind of skill to see the benefits in bad results, and I think so it is definitely an upgradeable ability too.
To shorten this section, I believe that always double-checking and making control measurements from different aspects are the best methods to avoid unexpected surprises that could arise during the project life cycle.
Be overprepared in every Field
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This is the best strategy for guaranteed success that almost always works, but what does it mean to me? Being overprepared is the wisest goal in terms of expertise, available tools, and parts since there is more room for maneuver if there are more alternatives.
From another aspect, I especially like to work with correctly calculated - or at least well-estimated - components in such a way that I prefer to use at least + 25% stronger building elements than expected. If this method is applied consistently, it can increase the upper tolerance of the system.
As I mentioned earlier, it’s worth being aware of the fine theoretical details, even for a cable that seems simple, because I find it necessary to know what material and what cross-section, and how many cores should I use for a given length. I didn't even mention my favorite well-proven cable brands. I am referring here to the quality of PVC or silicone insulation and the solderability of copper cores.
Of course, there are other important considerations as well. In addition to the calculated power transmission demand, it is essential to know whether our cable is intended for indoor or outdoor use. When choosing a cable, it also matters a lot whether it is used underground or on the roof in the sunshine and strong frost. What’s more, we even need a completely different oil-resistant cable if we want to use it in a garage for strong mechanical applications.
In summary, before we begin on such a seemingly simple task, it doesn't hurt to be overprepared with the necessary information before we buy something.
​​To achieve the best results, in other words, the desired quality, it is usually not worth replacing the necessary special tools with other doubtful bridging solutions, based on the well-known - this will be here certainly enough - principle.
That is why I prefer to use always the best quality tools and equipment, especially for electrical works. Last but not least, I think conscious and precise work makes a lot more sense.
