schematic puzzles for teaching?

markallen

I'm interested if there are any resourcers for teaching people how to read and debug schematics, specifically in the form of problems to be solved. For example, you could have the same circuit drawn in a different manner and people would have to figure out if it was equivalent. Or a schematic that might have a short or an error in it that you would have to locate.

I ask, because I teach electronics on occasion, and it seems that learning how to work with schematics in a very un-natural process for most people, yet so important to learning how to debug and build circuits.

I'd welcome any input or advice that anyone might have on this topic.

mojorizing

Hi Mark,
Check out www.etcai.com/ for a electronic tutorial.
It's a good educational aid for basic electronics and it's PC based.

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There are 10 kinds of people in the world.... those that know binary, and those that don't.

LoopyByteloose

If you are really, really into it.
The Art of Electronics has somewhat difficult ones (try to figure out why the circuit will not work) at the end of each chapter.

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G. Herzog in Taiwan

Beau Schwabe

Over the years I have been astonished on how many students I have run into that cannot interpret a schematic
anywhere outside of the book they used in school. Your idea is great in efforts to help the students see from
multiple avenues how to achieve the same result.

One type of "puzzle" that you have already mentioned, but perhaps with a different spin, would be to show two
identical circuits, except that the second circuit would have a NPN in place of a PNP and vise-versa, reverse any
DIODEs or CAPs, and finally reverse the power supply polarity. Show that the two circuits are functionally identical
assuming complementary transistors are used, and the circuit is a closed system.

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---

Beau Schwabe Mask Designer II National Semiconductor Corporation
(Comunication Interface Division)
500 Pinnacle Court, Suite 525
Mail Stop GA1

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OLD JOHN

There is a problem with the book, "What's a Microcontroller?" between the schematics and breadboard layouts. For instance, on the cover of my book is a schematic that shows a 220 ohm resistor connected to P3 and a junction with a 10k ohm resistor and a NO switch. The breadboard illustration shows the 220 ohm resistor connected to P3 and a junction with a jumper to Vdd and a NO switch.

I have a BASIC Stamp Work board which according to literature already has 220 ohm resistors connected to each I/O pin. Is it safe to ignore the breadboard showing an additional 220 ohm resistor?

thank you,

OLD JOHN

Aristides Alvarez

Hello John.

First let's talk about the cover example.
The schematic and the breadboard illustration are equivalent.

The 220 ohms resistor is connected to a node with other two components: the pushbutton and the 10K ohms resistor.
You can see that easily in the schematic.
In the breadboard area it's a little more difficult to follow a circuit wiring until you get used to do it.
(Breadboarding is explained on the previous chapter).

You have to take into account that the five holes in the same row are interconnected underneath the breadboard on each side of the central column (the empty space).
This is easier to follow looking at the graphics on the book.
Another thing to take into account is that the pushbutton is interconnecting both rows (left and right) and they become the same node, so the 10K ohms resistor that you see on the right side it's actually connected to the 220 ohms resistor.
This is covered in the previous two Activities in the same chapter.

Parallel rows are isolated one from another, so the red jumper wire it's only connected to the pushbutton and not to the 220 ohms resistor that it's two rows underneath it.

We made the circuits on the whole book compatible with the HomeWork Board and the Board of Education.
I recommend you to follow the wiring as shown in the book.
In the case of the HomeWork Board, as you noticed, you'll be actually using a total of 440 ohms if you take into account the surface mounted resistor that the Board already has.
This is fine in all cases so you can follow the original wiring diagrams.

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Saludos,
Aristides Alvarez
Education Manager
aalvarez@parallax.com
Parallax, Inc. www.parallax.com
California, USA

OLD JOHN

TO: Aristedes Alvarez

From: Old John, AKA The gringo padrino x 3

RE: The magic of being 12.

I am now 57, formerly 12. I am self taught, and have lived in the age of crystal radios, vacuum tubes, pre television, pre computer, and some say pre dirt. I learned basic electronics from a series of kits that were extremely specific. They did not equivalate, they did it. I do agree the circuit is equivalent, but it is hard to explain and hard to follow. I am thnking of my 9 year old god son in Morelia, who when he turns 12, I hope to start sending him kits like this. The thing that makes this difficult is the switch, which is a four terminal spst. It is not marked what is what.

I would like to see on breadboards, where two resistors meet in a node on the schematic, they meet in the same 5 pin row on a breadboard.

Personaly, I am excited about the book and the kit. I am already envisioning building a Parison programmer for the bottle blowing industry using this basic stamp idea and perhaps also using the stamp as an error amp for the same purpose. So, we are going to be using I/O as both.

So, when the cover says recommended for ages 12 and over, I figure this former 12 year old might be able to handle it. Ooh, it's tough to be humble.

Saludos,
Old John
Student
john1542chupa@aol.com
That suburb of Mexico city AKA Chicago