SPOT
THE MISTAKES!
Page 36
 

Page 1   Page 2   Page 3   Page 4    Page 5   Page 6   Page 7   Page 8   Page 9
Page 10   Page 11   Page 12   Page 13   Page 14   Page 15   Page 16   Page 17
Page 18  Page 19   Page 20  Page 21  Page 22  Page 23  Page 24   Page 25
Page 26  Page 27  Page 28  Page 29  Page 30  Page 31   Page 32   Page 33
Page 34   Page 35  

If you don’t spend time each day on studying electronics, don’t expect to gain the knowledge you need to make a success in this field.
You can see how much knowledge you need by simply going to the websites and video presentations where the presenters produce projects and modules with very little discussion and almost not technical information.
Most of the courses are also in this boat. The courses l have reviewed are mainly worthless. None of them discuss the actual operation of the circuit and it’s just a matter of “build it and watch the LEDs flash!” 
I actually gained my immense understanding of electronics by repainting thousands of electronics products. 
Not only did l have to learn how the circuit worked, but how it failed and why it failed and sometimes how to prevent it failing again.
This is way beyond building something and see it work.
The only time you will actually learn is when the circuit DOES NOT WORK. That’s when you have to sit down and think.
And that’s what is missing from all the University lectures.
Not one lecture or one text book, in 50 years, has mentioned the word:  IF IT DOESN’T WORK.
I call it:  REVERSE LEARNING.
I can prove my point.  A student came to my TV repair business. He was 16. He had never seen the inside of a TV.  He watched us for a few weeks. He then stayed in the workshop one night and fixed 3 TV’s with only “snow” because the channels went off at 10:30 at night.  He fixed a weak pictures via “snow level” and another sound problem  via “snow level.”
And he was fixing other problems from the knowledge he gained by watching us.
You may not have the advantage of learning in a laboratory or apprenticeship situation, but you can certainly gain a lot of understanding by building things all the time and use either a breadboard or a kit.
Electronics is one of the most difficult subjects to master and that’s why there are so few of us.
And the absence is in the basics. I have 250 modules on sale throughout the world and not one has been copied.
That’s because you need a fair amount of understanding to copy something and be prepared to build it and understand how it works so that any failures can be fixed.
The old saying is:  “DO YOU KNOW?  And do you know that you know you know?”   

3-TRANSISTOR AMPLIFIER

There is one problem with this circuit. It does not work

.

The problem is the value of the 330R across the speaker.
If we remove it, the electrolytic in series with the speaker will charge when the emitter rises but will not discharge when the voltage on the emitter reduces.
This is because the emitter lead does not have any connection to the capacitor when the voltage on the emitter is reducing.
This is how we see what the transistor is doing. When the voltage on the emitter is rising, the transistor is like a resistor that is reducing resistance and more current will flow through it and this current will charge the capacitor.
When the voltage on the emitter is reducing, the transistor is effectively increasing resistance and less current flows into the capacitor. It never gets to the situation where the capacitor is discharged.
All that will happen is this: The capacitor will gradually charge on each cycle and eventually become fully charged.
The circuit works like this: When the capacitor is uncharged, the transistor turns ON and current flows through the capacitor to charge it. This charging-current also flows through the speaker to produce sound.
On the next cycle, the capacitor will be slightly charged and so the chagrin current will be slightly less and the speaker will get less current to move the diaphragm.
Eventually the capacitor will be fully charged and the speaker will not produce any sound.
This is because the voltage across the capacitor is equal to the voltage supplied by the transistor. When this occurs there is no extra voltage for the “charging-process.”
Not w we add the 330R resistor.
One the first half cycle of the demonstration, the capacitor will be charged a small amount. During the rest of the first cycle we want the capacitor to be discharged so that is can be charged again. But to discharge it we need the discharging resistor to be the same value as the charging resistor. The charging resistor is the 8R speaker. So we want the discharging resistor to be 8R also. The only way to get this is with a zero ohm wire from the top of the capacitor to the 0v rail. This is called a short circuit and we cannot provide this. The best we can provide is a low value resistor of about 8R to 10R. This means the best we can do is half-discharge the capacitor. And it means current will be flowing through the resistor during both halves of the cycle. Current will flow through this resistor when the circuit is supplying current to the speaker and the circuit immediately becomes less than 50% efficient.
The discharge will be the ratio of 8R to 330R and is something less than 3%.
That’s why this arrangement is so bad.
The way the electrolytic works is this:  When it is uncharged, it acts like a low resistance resistor that connects the emitter to the speaker. When it goes high, the cone of the speaker responds. When it goes LOW, the cone returns to its rest position. But when the electrolytic charges, the slight voltage across its terminals DETRACTS from the rising voltage. This reduces the output from the speaker. If the electrolytic charges fully, the speaker gets no increase in current and the cone does not respond.

If the electrolytic is not discharged fully on each cycle it will gradually charge and the sound from the speaker will get weaker and weaker.
This is because the emitter will only start to pull the electrolytic up when the voltage is nearly at the maximum because the electrolytic already has a voltage across it. And this voltage detracts from the effectiveness of the transistor. When the capacitor is fully charged the emitter of the transistor will not be able to pull the capacitor up AT ALL.
We have already said the emitter has no ability to push down on the capacitor and the only thing that will discharge the capacitor is a resistor across it to the 0v rail.
The most effective value is 8R or less and since this will pass the same amount of current as the speaker, you might as well connect the speaker directly to the emitter and remove the capacitor.
This will solve all the problems as it will take no more current and deliver the maximum output.
There was no reason to add the capacitor. It did nothing and only created problems.
But you have to design the circuit slightly differently if you don't want "set the cone." This is the term used for reducing the current through the coil when it is directly coupled. The signal has to range from very low to a maximum. It cannot range from "quite a bit" to "a lot."  This will put current through the coil all the time a "SHIFT IT" from its rest position.
This adjustment is made by turning ON the first transistor quite a lot so the collector voltage is about 1.8v. This will make the emitter voltage of the emitter-follower transistor less than 06v and cause very little current to flow in the speaker coil.
You have to go through each component and work out what it is doing and if it is necessary. And if you can improve things.
It’s called: THINKING OUTSIDE THE BOX.

Here is another circuit with the same fault.  No-one on the web builds any of the circuits they show in their blogs.
The 560R to 100R ratio will deliver less than 10%. And the 10k to the electret microphone should be 100k for 12v
supply.

             THIS IS HOW TO ACTIVE A LED

Here is your instructor with his up-side-down circuit, showing ??????

I have no idea what he is showing.  I don't understand up-side-down circuits.

Here is the circuit correctly drawn. It is supposed to show a small current via the base  and a larger current via the emitter by the fact that the LEDs illuminate with different brightness. But HIGH BRIGHTNESS LEDs will illuminate with very little current and this demonstration will show nothing.
A circuit is an instantaneous picture. It is not to be turned-around or held up-side-down. If you can't see what is happening, you need to find out who is drawing the circuit. It looks like a BEGINNER.

I have looked at the ETron course for $99.00 and cannot see any value at all. The circuits have been taken from the web with no descriptions or explanations or details of how they work and overall the course has no benefits at all.
You can get all the components for a fraction of the cost from Chinese suppliers such as Aliexpress or eBay and look on the web for hundreds of circuits.
There are also many free courses but none of them explain anything and are construction projects without any learning.
This is generally the case because very few people understand how a circuit works and even fewer know how to write a technical description.
ETron is a typical example of a course containing more mistakes than you can “poke a stick at.”
It is so bad that l could not even give it a beginning rating. It has a value less than zero.
It ranks in my “Spot the Mistake” as a learning curve to teach you how not to design a circuit.
And for that reason l have included it here.
You can also get my previous comments on page 30:



MAKE
Once again, MAKE have sent me an email from their bulk-emailing list and have the cheek to send out a promotion of all their old books with the myriad of mistakes, for an absurd price of over $120.00. They say they have sold over 200,000 of the first edition and that’s 200,000 beginners who have been “lead down the garden path” and steered in the wrong direction, with the enormous number of mistakes in these books.
That’s why, overall, sales of kits and projects to American students have been incredibly low. They are not being taught anything from these books and don’t understand what they are doing.
Electronics is not a “build it and watch the LED turn on and off.”
This teaches you NOTHING.
After all, our TV’s were made down the road by local women and after 20 years, they learned nothing about electronics.
The author behind these books has a very little understanding of electronics and explains nothing about how the circuit works, or how to fault-find.
I have already contacted the author and the publisher and absolutely nothing has been done to rectify or remove the mistakes or provide an “errata sheet.”
And now they send out another email with edition 2, 3 and 4. But when you go to the listing you find the edition is an old version.
The same applies with the courses from other “shysters.” Their $100.00 course is simply old circuits from the web, constructed on bread-board that is no longer available, with photos that l cannot follow.
In both cases you can get the components from Aliexpress for much less than half the cost.
I would not complain if the courses provided the slightest amount of instruction. The slightest amount of learning. The slightest amount of education.
The problem is they ruin it for genuine kit suppliers. The enthusiasts have already “had their fingers burned” by these “rouge” shysters and have stopped buying.
The internet started with lots of “criminals” wanting $30.00 per month to join a course or data sheet supplier. Eventually this failed and one suppler made the offer FREE.
All l have done is ask these suppliers to send me a copy of their work so l can correct the mistakes.
Not a reply.
They have no interest or incentive or intention to improve their “junk.”
There is no-one more stupid than “he who does not see.”
They are so dumb as to be unable to “get out of their own way.”
There is very little need for electronics understanding because most electronics is built around digital circuitry and modules.
But the problem exists when interfacing a design to an input device.
This is where your knowledge of impedance-matching and programming is most-needed.
And that’s where the vacuum is.
No course or lecture explains this.
And that’s why you have to go through my hundreds of pages of explanation of how circuits work, to learn about this.
It is all provided for free and over 25 million visitors have come to the website.
It is up to you to get involved and create your own projects and products.

And finally, l received an email from a professor, touting his capability in teaching how to improve your life and business skills.
Remember this. Professors are no better than the worst employee you could ever imagine.
They are totally incapable and incompetent in this world.
The only thing they are good at it is: REMEMBERING.
They are “parrots.” They simply regurgitate what they have been taught.
I am mainly talking about the electronics industry where you need to understand. With mechanical engineering you can see what you are doing. Electronics is invisible. You have to understand. That’s why it is one of the highest disciplines.
And in that regard l have not seen a single lecture where the professor has explained anything at all level that the beginner can understand.
They have no concept of “thinking outside the box.” Come down “three rungs of the ladder” and say: “this pushes UP, this pushes DOWN.” Forget mathematics, forget microscopic differences. Forget calculating to the “n’th” degree.
Get the message across with a huge prototype showing the transistor operating.
This might cost $2.45. But “hang the expense.” Throw all your money into the demonstration. Get your lecture across.

The correct layout from the discussion above