SPOT
THE MISTAKES!
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These pages are one of the most important features of our website.
They show how easy it is to produce a mistake.
It's very easy to forget to include something, but it is unforgivable to state something that you haven't researched or checked (by simply Googling the answer).
We all thought Google was a made-up word until its meaning came through as the "amount of money you need to retire on" - $10¹⁰⁰
A $1,000 life insurance policy in 1920 could buy a double-brick house.  In 2104 it does not pay for a coffin.
You need $1,000,000 to retire comfortably and this will just buy a rental property to provide a good living.
What will be the statistics in 20 years?
That's why you need a plan to set-up a business that will see a good return so you can buy into the rental market.
Houses are the only reliable safe-guard. Everything else can rise and fall.
You need to think of a product you can market and promote for years to come.
And electronics can do this if you look into the fields of health, aids, and toys.
They are all areas where hundreds of thousands of units are sold and if you simply look around and see something that YOU need, chances are OTHERS WILL NEED THEM TOO.

My biggest regret with TE website is this: I didn't organise it as an ENCYCLOPAEDIA.
There are so many facts and circuits on the site that it will fill a book.
Most of the information is NEW and not just a re-gurgitation of text-books from the past.
Text books are wonderful. But they are frustrating. They explain a point in such a way that the beginner doesn't understand what is being said.
Two facts come to mind:
No text book has explained how the protection diodes on the input of a CD4001 or CD4011 discharge the capacitor in an oscillator.
Text books also say: A collapsing coil produces a voltage IN THE OPPOSITE DIRECTION.
The word: "back EMF" does not have the same impact as saying: the voltage is produced in the REVERSE DIRECTION.   Once you realise it is a REVERSE VOLTAGE, you can understand how a TUNED CIRCUIT WORKS.
However I made a huge change to the website when I introduced "frames" and added the left index. This allowed easy access to all the folders.
But if I had added alphabeticalisation and links within each of the articles, the reader would be able to refer to other articles in the website.
Fortunately we have an answer.
Simply use Google. Type: talkingelectronics.com tuned circuit   into the address bar and within 0.001 seconds you will have all the occasions where I have used this term.
Every word in every sentence of Talking Electronics website has been indexed by Google.
That's the power of the "robot."



Here's some more mistakes from Mike Tooley's text book:

I can't work out what he is talking about, and I have studied the 555 for 25 years !!!
There is No TR1, no IC1, what "buffer" ??? 
How do you expect a beginner to understand this gobbeldy gook !!!
 

The "STOP" should be called "RESET."   

590kH is a $30.00 temperature sensor !!
You can buy a complete IR temperature "gun" for $25.00!!

REGULATED SUPPLY

All the writings in this books are simply a re-gurgitation of things you can find in ANY text book. Nothing has been explained in a way that is NEW or easy for a beginner to understand.
Take the Regulated Supply for example.
The output transistor is actually an EMITTER-FOLLOWER and when you draw the circuit as shown in the second diagram, this is obvious.
The pot forms a voltage divider in which the slider (the wiper) is picking off a voltage from 0v to 13v from the outer track of the pot.
This is passed to the transistor and it "rises and falls."  The emitter lead is the output and it is always 0.7v below the voltage on the base. That is why it is called a "follower."
But the transistor provides an additional feature.
The emitter voltage is much smoother than the voltage on the collector. And this is why:
As you increase the voltage (by turning the pot), the current required by the load will increase and the voltage on the 2,200u can drop from say 15v to 14v. This is because the electrolytic is like a miniature rechargeable battery and it charges-up when the voltage is high and delivers its energy when the voltage is lower.
But when the current you are drawing for the circuit increases, the electrolytic cannot deliver enough energy and the voltage "dips." There will be 100 "dips" for a 50Hz input from the mains.
If you deliver this voltage directly to an amplifier you will hear a lot of buzz and hum. But if you are able to use the voltage UP TO 14v, the result will be perfect.
That's what the transistor does.
It just uses the voltage from 0v to about 13.9v so no hum is delivered to the output. 
So, what happens in reality is the output voltage can reach a maximum of 12.3v and the 15v appears on the collector so the transistor "deals" with 15v - 12.3 = 2.7v across the collector-emitter terminals  (collector-emitter junction). The voltage can go as low as 14v - 12.3 = 1.7v across the junction.
The transistor can only perform this "magic" with currents up to 350mA because the transformer can only deliver 500mA AC and when this is passed to the transistor, the current must be de-rated.
WHY?
Because the wattage delivered by the transformer is an AC rating of 12v and 0.5 amps = 6 watts. The 12v is an RMS value and when it is rectified, it emerges from the bridge as a peak value. This value is 40% higher than 12v and becomes 17v. So, to keep the wattage emerging from the rectifier 6 WATTS,  we must DE-RATE the current by 40%.   In other words xxmA x 17 = 6    xx  = 6/17  = 350mA
This explanation has been missed by Mike Tooley. He said the circuit is capable of supplying up to 500mA. This is UNTRUE.
Instead of my simple explanation, he says the transistor is used to provide current gain.  How is a beginner supposed to know what that means????
He doesn't explain ANYTHING.
But what he is trying to say is this:
The zener is providing a stable voltage of 13v. If you use a high-wattage zener and a high-wattage wire-wound pot, you could get 0v to 13v from the wiper (slider) and remove the transistor.
But this would produce a lot of wasted heat and the circuit would be very inefficient and completely "unregulated."
By using a transistor we can reduce the wattage of the zener to 1% and the wattage of the pot to 1% and get REGULATION. This is because the transistor has a gain of 100. We are saying the transistor has a gain of 100 to make our discussion easy to understand.
The transistor will amplify the current one-hundred-times. It will amplify the current into the base one-hundred-times.
This is what he means by the transistor is used to provide current gain.
The current into the base will be multiplied 100 times and this is the maximum current that can be delivered by the collector-emitter leads.
But Mike Tooley does not realise the current into the base is very small. He has not worked out the actual current that will be delivered as the pot is rotated. 
This value MUST be worked-out if you want the circuit to work.
This is called the CURRENT-SIDE to designing the power supply.
The output current will be 350mA, so the base current will need to be 3.5mA.
This 3.5mA will be "robbed" from the zener.
In other words, the zener must pass more than 3.5mA because we will be taking 3.5mA from it.
The voltage on the 2,200u will be 12v x 1.4 - voltage drop across two diodes = 15.4v
The zener voltage is 13v so the current through the 150R will be 16mA.
The zener is passing 16mA and we want to rob 3.5mA.  This part of the circuit is correct.
BUT:
The current through the 5k pot will be as low as 2.6mA when it is turned towards the 0v rail. So you can see the pot will not be able to deliver the 3.5mA required by the transistor.
The pot should be 1k. But a 1k pot will allow 13mA to flow and this will make the pot very HOT.
This is where the circuit "FALLS OVER."   It has not been tested or designed correctly. 
The transistor actually has a maximum gain of 70 and is a very poor choice for this circuit.
The end result is: THE CIRCUIT DOES NOT WORK.


SINEWAVE OSCILLATOR

These circuits produces a sinewave very nearly equal to rail voltage.
The important feature is the need for the emitter resistor and 10u / 47u bypass electrolytic. It is a most-important feature of the circuit. It provides reliable start-up and guaranteed operation. For 6v operation, the 100k is reduced to 47k.
The three 10n capacitors and two 10k resistors (actually 3) determine the frequency of operation (700Hz).
The 100k and 10k base-bias resistors can be replaced with 2M2 between base and collector.
This type of circuit can be designed to operate from about 10Hz to about 200kHz.
Both these circuits are NOT VERY RELIABLE. They work with some transistors better than others. They stop working when you touch some of the parts. The frequency changes when you add a 100u across the power rails. They are too fiddly to be recommended.  Place a piezo diaphragm across the collector load and experiment yourself. Try changing the 1k and try 6v to 12v to see what I mean.

Mike Tooley says: This is the book that I wish I had when I first started exploring electronics nearly half a century ago.
Apart from the fact that many of the explanations are given in a complex way, nowhere in his book does he mention the TUNED CIRCUIT. This is the most important building block to be invented. It pioneered the ability to transmit a signal over a long distance with very little power and obviously was the basis to RADIO. Without radio we would not have TV, RADAR, internet and the most important thing of all APPLICATIONS ON iPHONES.
He also mentions the inductor and the fact that the voltage produced by a collapsing magnetic field produces "back e.m.f "
But that will go over the head of a beginner without saying this is the most amazing thing of all. The voltage produced by an inductor (when it is turned OFF) produces an OPPOSITE POLARITY VOLTAGE (to the supply voltage) - a voltage IN THE OPPOSITE DIRECTION.
Once you know this, you can work out how a capacitor and coil in parallel produce a natural sinewave without any other components. And the voltage they produce can be TWICE the value of the supply !!!! It is called a  TUNED CIRCUIT or TANK CIRCUIT (when referring to radio circuits and transmitters).

Mike Tooley has never learnt how to draw circuit diagram. That's because they don't mean anything to him.  He draws 555 blocks with pins "all over the place" and connections to these pins all over the circuit.
In fact he has hardly covered the 555 at all. This is one of the most popular chips and he has only shown a few circuits.
Also he has not even covered the most universal Schmitt Trigger IC - the 74c14. This is a hex Schmitt Trigger with an enormous number of applications.
As I said, it is obvious he is not a "down-to-earth" design engineer and cannot relate to the circuits because he has never even built any of them.
One FLIP-FLOP circuit does not make you a DESIGN ENGINEER.
His book is like giving you all the fancy LEGO BLOCKS without the 3 BASIC BLOCKS. What can you build ??
No transistor circuits, no gate circuits, no microcontroller circuits - no nothing.

Here is a paragraph from 2015 "Teach-In."

The maximum total power dissipation is important in a number of applications, particularly for devices where appreciable power is being delivered. In the case of this family of devices, the total power dissipation (the sum of the power dissipated in the two junctions) should be no more than 500mW. So, in an application where the collector-emitter voltage is 15V and the collector current is 400mA the device will be operating outside its maximum permissible ratings even though the collector-emitter voltage and collector current do not individually exceed the manufacturer’s specification.

What is he talking about ???
I don't know.  How can a beginner understand this ???

You don't calculate 500mW by multiplying 15v by 400mA.  500mW is determined by measuring the voltage across the collector-emitter terminals when 400mA is flowing. The voltage might be 300mV to 800mV.
If the transistor is turned on FULLY, the collector-emitter voltage will be about 300mV. If the current is 1,000mA, the dissipation will be 300mW. (1,000 x 0.3)
If the base current is not sufficient to FULLY turn the transistor ON, the collector-emitter voltage will be higher than 300mV and can be say 800mV. In this case the dissipation will be 1,000 x 800 = 1,000 x .8 = 800mW and the transistor will overheat. 

Here's more "technicalese" that needs simplification.   Remember, he is supposed to be talking to BEGINNERS:

Look at the quality of this board from Gadget Gangster

PC boards made by Chinese manufacturers cost LESS than doing it yourself.
The board above is a double-sided, plate-through-hole with tinned solder-lands and a legend on both the top and bottom.
It is made by Nicholas McClanahan, a hobbyist who takes pride in his work and produces BEAUTIFUL boards.
This is the sort of quality that should be presented in Mike Tooley's text book, to show the reader HOW things should be done.

Here's a piece of re-gurgitation I spoke about above:

It is a common base stage.
Although the arrangement is correct, a practical arrangement is different. More biasing components are needed. The operation of the stage is not covered in the text. Why include an impractical layout for a beginner and fail to describe it. ????
The common base stage will interface (connect) a very low impedance transducer (such as a speaker or coil) and amplify the signal 100 to 200 times with minimal distortion because of the direct coupling. One or two practical circuits are needed to show the value of the surrounding components.
The author is treating the readers as IDIOTS. He is asking them to buy a magazine and then producing HOT AIR. You can get better information on the web FOR FREE.
The Phase Shift for a common base stage is 0°.   In other words, the input and output are IN PHASE. The waveforms on the diagram above are NOT CORRECT. The red output wave should be drawn "up-side-down."
 
Mike Tooley claims the voltage gain of common-emitter stage is Medium/High (40). However the gain depends on how the stage is biased. Self-bias gives a gain of about 70 but other biasing arrangements can produce 100 to 250 or more. Power stages can be as low as 10 to 25.

Mike Tooley also talks about transistors with a gain of 100, 220 and 450. What he fails to mention is this:
When a transistor is placed in some circuits, the resulting gain of the stage is almost the same for any of the transistors.
It all depends on the way the circuit is biased. After all, biasing is designed to maintain the same gain, irrespective of the temperature of the transistor and also produce nearly the same stage-gain for a wide variety of transistors. 
It is only under very special circumstances that the full gain of the transistor can be obtained. In fact it is so hard to determine the gain of a stage before-hand, that you need to build the stage and try different transistors to see if any variation is produced.
The worst common-emitter stage has the base resistor connected to the positive rail and the resistance of the collector load is adjusted to produce about half-rail voltage on the collector. If the transistor is replaced or heated, the collector voltage will rise or fall considerably.
The next worst common-emitter stage has the base resistor connected to the collector. This is called SELF BIASING and the collector voltage will change slightly if the transistor is heated or replaced. It is much better than the worst stage but transistors with a gain of 100 will produce a high voltage on the collector and a transistor with a gain of 450 will produce a low voltage on the collector.
The next type of common-emitter stage has an additional resistor between the base and 0v rail.
The produces a lot more stability but it decreases the gain of the stage considerably.
Finally, biasing via 4 resistors in a "bridge" arrangement provides a high degree of stability but the gain of the stage is reduced.

He also throws in things like this: Notice that there is a fair amount of variation across the three gain groups. For example, the data shows that the input resistance (hie) for a device in Group C could easily be more than four
times greater than that of a device taken from Group A.
He offers NO EXPLANATION - so why bring it up??????? He does not know the answer !!!
The reason is this: all the transistors are tested with a collector current of 2mA. To produce a collector current of 2mA with a transistor having a gain of 100, requires .02mA (20uA).  To produce a collector current of 2mA with a transistor having a gain of 400, requires 5uA and the base-emitter junction will not be turned ON as much and it will "appear" to have a higher impedance.

Mike Tooley says:  "where direct voltage is amplified as well as AC."   I have NEVER heard of: "direct voltage." 

How does the circuit remove the charge on the capacitor (the piezo is a capacitor) when the output of the chip is "OPEN COLLECTOR."

How is the circuit improved  ????      Mike Tooley does not say  !!!!!

 Mike Tooley claims these two coils make a transformer. They are so far apart that the magnetic flux from one coil will have very little effect on the other.

His coverage of 5 band resistors is very poor. It is NON-EXISTENT.
5-band resistors are easy to read if you remember two simple points. The first three bands provide the digits in the answer and the 4th band supplies the number of zero's.  
Reading "STANDARD VALUES" (on 5-band resistors)
 5-band resistors are also made in "Standard Values" but will have different colours - and will be confusing if you are just starting out. For instance, a 47k 5% resistor with 4-bands will be: yellow-purple-orange-gold. For a 47k 1% resistor the colours will be yellow-purple-black-red-brown. The brown colour-band represents 1%. 

He has 3 pages on soldering and NOT ONCE does he talk about the diameter of the solder.
He has NEVER SOLDERED IN HIS LIFE.
You must use solder with a diameter LESS THAN 1mm.
0.8mm solder makes a much better connection than 1mm and 0.6mm makes a PERFECT connection.
I have never seen this mentioned in any soldering articles.

Another wasted chapter is on MICRO's. He discusses the Z-80 and PIC micro in general terms but does not offer any first-hand commentary.
the Z-80 was one of the first 8-bit microprocessors but needed an external clock, RAM, ROM and decoders as well as latches to get anything up-and-running.
It had about 700 instructions but you very quickly ran out of registers to store information.
Almost all the capability of a Z-80 can be handled with a PIC16F628 at $1.50 and the PIC chip has only 35 instructions to remember. Out of these, you only use about 10 on a constant basis.
He covers the 35 instructions (called mnemonics) because each letter of the instruction represent a word in it capability. But he then presents a program in "C" and never covers a program in ASSEMBLY (a program using the 35 instructions).
It's only someone like me, who has worked with both micros, that can review the chapters and see how badly they have been presented.
A newcomer simply says: "microcontroller programming is NOT for me."
His text book has not give me any incentive to study electronics and you can find more-exciting discussions on Instructables or Make.  
 
I also have a point-of-difference with the way he has described the operation of a simple common-emitter stage.
The stage is biased with a base-resistor to the positive rail and although he has described its operation correctly, this type of biasing is never seen in reality as it depends HEAVILY on the gain of the transistor to maintain half-rail voltage on the collector.
He covers the base current required to obtain mid-rail voltage and then talks about a 15uA input signal to produce a 3v signal on the collector. This is all correct, but in reality, how are you going to find, detect and view a 15uA signal. You may be able to view all this on a simulation package, but in reality a Cathode Ray Oscilloscope only displays signals with AMPLITUDE. 
That's why you have to decide if you want to build "pretend" circuits or learn how to diagnose actual circuits.
He should have made this clear to the beginner and gone on to describe a self-biased stage.
What he has described is quite NON-FUNCTIONAL and useless.

Simply looking at the comments and mistakes above, it is clear Mike Tooley does not have a firm understanding of the basics of electronics.
An email from Mike Tooley confirmed my thinking.  He has no idea how the Regulated Supply (circuit above) works and how to comment about the mistakes.  
We will see what mistakes appear in the second installment of Teach-In 2015.

I received this email today and I am going to respond to it because it brings up two points from the current item.
If anyone sends and email with any derogatory comments I will also present them too, because I intend to cover everything and not filter anything out.

This email comes from Dave Thompson NZ

The magazine subscription figures seem very low and it would be almost not worth publishing. The projects they offer are usually quite good in my inexperienced opinion but with the variety offered and the fact that with electronics every reader's level of experience is different it makes it hard to find the right balance between simple to make and in some eyes a waste of time and money to being too expensive or complicated for the average reader.
Essentially the same four or five guys design projects for Silicon Chip and while I used to subscribe to EPE I flagged it in the end because the projects they were publishing were re-hashed Silicon Chip articles that I'd already paid one subscription fee for.
I sent a letter to the editor of EPE stating exactly that and they didn't deem it fit to print.
Still, the quality of those projects is better than EFY, which I also subscribe to, and which you show up a lot in your 'Spot the Mistake' pages.
I'm not experienced enough to find mistakes as I'm nowhere near the level of 'seeing' circuits in action just by reading the schematic - part of me going to TE is to try and up-skill so that I can get to that level but I think it is something you either have or haven't - and I haven't.
Sadly in Oz and NZ if you stick your head above the parapet you can guarantee someone with no skills and no hope at all will try to shoot you down and that is a culture I cannot abide by - it keeps society in the dark ages and squashes motivation.
If you want to use anything I say as a testimonial on your site you are welcome to do so.

Kind regards --
Dave Thompson
dave@pcanytime.co.nz
Christchurch  NZ

Thanks Dave,
I have had many comments from readers who have written to EPE and not received a reply.
Many readers and advertisers have commented about the re-hashed articles from Silicon Chip.
This whole interaction with EPE started when I offered 30 new projects and they were FLATLY turned down.
On further investigation I learned from an advertiser that Matt Pulzer (the editor of EPE) said he could not accept projects because  "they couldn’t accept them because they had no way of checking them for accuracy."
Then I find Matt Pulzer saying he will learn a lot from the basic "Teach-In" series.
The advertiser went on to say: "I don’t understand why people buy the magazine when they could get the projects from Silicon Chip magazine by subscribing to that magazine instead of waiting a couple of years to see them repeated in EPE."
The second thing I want to comment on is "SEEING A PROJECT WORKING."
I have been criticized by two electronics "PROFESSORS" for making such a STUPID comment. How can a person SEE a circuit working ????
How do you think Whitworth SAW the wear on the teeth of his reduction-gear and work out how to reduce the wear  ????
He saw the problem in his "MINDS-EYE."
To see what I mean by "seeing a project working" we just have to take the Regulated Power Supply circuit above.
This is reproduced from the 3rd edition of a text book that would have seen by 10,000 readers, including lecturers, teachers and students.
NOT one person could see the fault in the circuit.
When I emailed  Mike Tooley, he made a vague comment about the 12v AC should be increased to 15v AC "to give the regulator headroom."
From this comment it was obvious he did not understand how the circuit worked.
That's why he did not explain it in his text book and that's why none of the readers were any the wiser.  The whole discussion was a WASTE OF TIME. 
Don't you think I can detect the competence of a person after teaching for over 30 years ?????
Just like I can recognise a politician after listening to 2 words, I can see if a person understands what he is talking about after a few comments.
I can see Mike Tooley has never done any soldering, never made a PC board, never made a project and never done any fault finding. He has never even looked at a 1% resistor.
If he had done any of these things he would have mentioned the tricks and traps to avoid.
He doesn't mention to use THIN solder, he doesn't mention that a 555 takes 10mA when sitting around. He doesn't mention a 555 is not an ENGINEERS chip - it is only suitable for automotive projects as it CROWBARS the power rails. His PC boards are absolutely atrocious and if any staff member made a SHIT board like his, he would be fired immediately. Even my first-year apprentice made boards I was PROUD OF.
Mike Tooley has a cheek to put himself up as an instructor. Not once does he say how the energy from a transistor stage is passed to the next stage. And he makes stupid comments about the output of a stage is 30R when the pull-down resistor is 2k. He does this because he cannot SEE a circuit working and that immediately put him in a position of not being able to teach.  Or more-accurately not being ALLOWED TO TEACH.
It's no wonder Everyday Practical Electronics is going down the gurgler; like the Titanic, it is just a matter of time.
The readership has plummeted in the past few years. Readers are seeing there is nothing in each issue of the magazine.
The projects are "boring" and no-one is offering kits. None of the projects are simple  - for a beginner and the Forum is monitored - with negative comments removed.    
Teach-In posts on the EPE Forum, have dropped from 15,000 in 2010 to 75 posts in 2011. And yet Matt Pulzer says Teach-In is one of the most popular articles in the magazine.
The global acceptance of any website is indicated by Alexia and Talking Electronics has a rating of 179,864 to represents 6,000 visitors each day. EPE has a rating of 3,044,165  and Silicon Chip is  621,393
There is no direct relationship, however the equation can be 3,000 visitors a day for Silicon Chip and 300 to 600 a day for EPE.
EPE offers nothing on their website except a JUNK soldering guide for $10.00  WHICH HAS NOW BEEN REMOVED !!!
If anyone has the slightest feeling that I have made an incorrect comment, please email me.
These comments are only a FRACTION of what I am REALLY feeling.
The way people have been treated by Silicon Chip and Everyday Practical Electronics is ABSOLUTELY ATROCIOUS and I can extend this to many of the text books I have downloaded.
To charge $30.00 for a text-book filled with re-hashed re-gurgitated verbiage is absolute dishonesty.
It is no wonder hundreds of visitors have said they have learnt more from my website than all the University courses they have undertaken.
The only problem is this: I have only covered the very basics of electronics.
Once you get to higher levels, mathematics takes over and faulty thinking is less evident.
No-one has covered the transistor amplifier in more details than me and after 300 circuits, I have only covered some of the circuits.
To put ONE circuit in a text book and call it COVERAGE, is beyond me. What does Mike Tooley think he is doing?????
 

The caption is the same for both figures !!!

The explanation is just gobbeldy-gook.

The diode and SCR have been drawn as
they would appear in a circuit

 
The transistor has been flipped over

This diagram shows the input and output of the bridge