What to put in a HIGH SCHOOL intro electronics course?

I would start with an old elcheapo analog scope and a similar quality speaker such as from a little transistor radio. Start with it at a low sweep speed and let one of them with a decent voice sing a note into the speaker and watch the scope.

At the slow sweep you see like an envelope but them have them keep it up and crank up the sweep speed until you can see the waves. (of course you are on autotrigger)

Have another speaker laying around, a bit bigger one and tear it apart so they can see it is basically a magnet and a coil like many motors.

Actually I would start with the scope and a battery. That demonstrated DC. THEN move on to the little speaker that acts as a microphone.

Then you get to the explanation of just WTF happened here. It should get their interest enough.

Whatever you do, don't bore them with the chemical reaction of a lead acid storage battery like they did me. And all the formulae can wait.

I would put Ohm's law up on the board and tell them to ignore it. Then go on with the headlight story.

Your car headlights are 36 watts. They get 12 volts and they pull 3 amps. They pull three amps because they are 4 ohms. Volts and amps are quantities, Ohms are the ratio between these two quantities. Explain it that way.

And whatever you do, when you get to the little bit more advanced stage, DO NOT conflate out of phase with polarity. I have almost gotten into fights over this. Out of phase is NOT the same thing as out of polarity, just look at a sawtooth wave. For symmetrical waves it can almost be considered so, but do not leave out that important fact from their basic understanding.

Anyway, the cathode ray oscilloscope and an analog meter are very useful visual aids. If the class isn't really tiny, you might want a camera and a TV to enlarge it so they can all see it. These days that shit is not expensive. If you have a budget to do it that is great, but even if you buy it on your own you still have it, and it won't break the bank.
 
>"I bet that nobody know why the silicon diodes do not work in such >circuit. "

A Schottky would.
 
In article <ML6dnaqII9D8L_zLnZ2dnUU7-XGdnZ2d@supernews.com>,
pcdhSpamMeSenseless@electrooptical.net says...
When I took basic electronics in high school, the one great thing my
teacher did was allow me to walk out of the class with a cool project
within the first two weeks of class. In this case, it was a roulette
wheel that made a sound while the LEDs lit up around in circles.

I recently taught an intro digital electronics course. And, I did the
same approach. But this time, the students built an Apple 1 replica,
using a simplified design with only a few caps and resistors, a 6502
CPU, a 6821 PIA, and a propeller chip. And with it, we did other
things with it like turning on LEDs through BASIC. The students
walked home with a fully functional computer. This is the kind of
thing that keeps students engaged. I'm not sure what your budget is,
or if you're going to charge lab fees. Something like an Apple 1 can
be built under US$50.


_That_ is a cool class. Can I sit in on your next one?
Click to expand...

6502 ? ;0 time warp!

LDA $00,Y
STA $01,X
JMP ($0300)

The list goes on.

Jamie
 
<jurb6006@gmail.com> napisal w wiadomosci
news:11a644a8-75d5-40c7-a350-908323e45d07@googlegroups.com...
"I bet that nobody know why the silicon diodes do not work in such
circuit. "

A Schottky would.
Click to expand...

In the circuit the electrons can flow from the ground into the antenna only.
https://en.wikipedia.org/wiki/Crystal_radio#mediaviewer/File:Simplest_crystal_radio_circuit.svg

Why and for what?
It is the question for students.
Can you give them the proper answer?
S*
 
Uzytkownik "amdx" <nojunk@knology.net> napisal w wiadomosci
news:n3pn8c$v8q$1@dont-email.me...
On 12/2/2015 11:08 PM, Ecnerwal wrote:
I want to offer basic concepts and hands-on, use a soldering iron, make
stuff. Without treating it as magic, I'm also facing the fact that
there's no assuming that the students will have had any advanced
mathematics, so I'm going to need to step away from messy math and stick
to simple stuff and the occasional "you'll learn more later."

How about teach and build a basic linear power supply.

What does the transformer do?
What does the bridge rectifier do?
Ripple
What does the filter cap do?
Filter size
What does this series resistor do?
Why did it get hot?
Oh so if we use two-1/2 watt resistors instead of one!
What does the zener diode do?
What does the Pass transistor do?
What is the load.
What is the load current.

There is a whole lot of learning in there.
Transformer ratios, different filter caps,
current flow through the bridge rectifier,
AC to DC,
Click to expand...

Now is XXI century. It is the last time to start teaching about the impulse
currents:
https://en.wikipedia.org/wiki/Impulse_generator

The Ruhmcorff coil produces the impulse current:
https://en.wikipedia.org/wiki/Induction_coil#/media/File:Induction_coil_waveforms.svg

Such coil should be in each high school.
E. Thomson (19 years old) discovered the electric waves transmitted by the
coil.
The waves transfered the electric charge through the walls in the big
building.
It was obvious for him that the waves are usefull for the long distance
comunication.
S*
 
On Thursday, December 3, 2015 at 12:09:00 AM UTC-5, Ecnerwal wrote:
I'm contemplating offering a basic, assume nothing electronics course
during the "winter-session" at our school. 17 meetings over 5 weeks
totaling about 40 hours.

I want to offer basic concepts and hands-on, use a soldering iron, make
stuff. Without treating it as magic, I'm also facing the fact that
there's no assuming that the students will have had any advanced
mathematics, so I'm going to need to step away from messy math and stick
to simple stuff and the occasional "you'll learn more later."

By the time I actually _learned_ any of this stuff, I'd had 4 semesters
of college engineering math and 1 or 2 barf-back EE courses that taught
me nothing of use. Then I took electronics for physics and the textbook
was AoE and the focus was on understanding things, not just memorizing
what gain formula went with what resistor configuration around an op-amp.

But I can't really see trying to force feed AoE (though I still like it)
to high school students (nor make them buy it for a 5 week course that
won't work far into it.) On the other hand, I'm certainly not looking to
repeat my glorious barf-back (rote memorization) experience, which
really was a waste of a class.

I can probably limit the class to 5 or 6 students, (it's one of many
offerings in a small school) and meeting times are all long enough to
get some hands on in every session.

I don't have much of anything nailed down yet, but will need to do so by
January (and decide if I'm gong to take a stab at it by Saturday.)

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.
Click to expand...

I started a blog for very similar purpose, last year:

transistorize.me

It might inspire you. The site is support a workshop I do at the Maker Faire (free parts, no pre-requisite knowledge). Though, the majority of my audience would be 5-8 year-old kids. I don't try to "teach electronics" much, just teach how to build the one circuit, and modify it. The goal is just to spark an interest. Good luck,
- Rich S.
 
Well, I put a course description out there, we'll see what I get for
interest in a couple of days.

Have scope, (and a couple of less-likely scope-shaped objects_) have
counters (through I don't know that I'll use them), have multimeters,
have an AADE L/C meter, have a millivolt potentiometer with standard
cell (so retro...) have analog meters, have various irons and a hot-air
rework station.

Might actually break down and try lead-free solder (something
super-skinny from Multicore by preference, based on my leaded solder
history), though that continues to be far less of a concern in the US
than the EU (I have always and will continue to advise hand-washing
after soldering and before eating, but there's no need to get silly
about leaded solder - teen-agers are fairly unlikely to eat the stuff
directly.) I believe it's still miserable .vs. tin-lead but I'd hope
that most of the major problems it used to have have been resolved by
now.

I'm unlikely to go for the power supply both for the "not so
interesting" (and often makes sense to just buy) and more importantly
not too sure I want to unleash the kids and line voltage, though we will
probably visit that subject for a few minutes just to sweep out any
utter ignorance.

I think I will give some variant of the crystal set a whirl if only for
the opportunity to play with the foil and waxed paper capacitors.
Probably not first out of the gate, though. Something flashier first.

I have doubts that I'll bother with any resistor color code mnemonic -
the one stuck in my head is not suitable, and most of the "clean"
versions at wikipedia don't resonate - and there are no color codes on
SMD resistors - plus this is a generation that is wildly unlikely not to
have a device (or three) they can look them up with on hand at any given
moment. I also never much liked the fact that little complexities like
silver and gold multipliers are glossed over by focussing on memorizing
the basic code. Point them at a full chart, make sure they can use it,
and let it be. If electronics takes, they'll either get around to
learning it (if they even use through hole components) or find an app
for their phone that will tell them resistor values when they take a
picture ;-) (you may think I'm kidding - I'm not - if it's not already
out there, I strongly suspect it will be.)

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.
 
Really, you are not likely to get very far in 40 hours. Start with DC, use the easiest example, like my car headlight thing, 36 watts etc. The little speaker used as a mic brings in AC as well as the relation of electricity to magnetism. Both are well displayed by an old analog CRO. The problem is the screen size, if you are up in front will they be able to see it ?

Biggest scope screen I have seen is an HP54501A, and though it is a CRO it is not analog. I think there is alot of value in them watching the dot move across the screen and then seeing to turn up the timebase. I have a Tek 7603 around that has a real 7" screen unlike the storage version that only use about 5.5" of the screen because of the mesh storage system. I have a 561A, while it has a HV problem, produces a trace bright enough that with a lens it could be projected. Maybe all you need is a video camera and a TV. The school might already have them for you to use, dunno.

And not only with the speaker as a microphone, how about a function generator and amp feeding a speaker so they can see the cone move. Of course they will have sen that but maybe seeing it that way might enlighten a bit. And maybe bring in a musical instrument and play it through all that. Just a little primer on harmonics. An elcheapo keyboard with a;ot of voices might do well at that.

With the exception of basic Ohm's law I would not try too much math. You can go into impedance calculations around the end of the course. If you get that far in 40 hours I think you did pretty good. It is hard for people because this is all new to them. By the time I got any electronics in school I was already fixing things. I already had a scope and it taught me quite a bit at an early age.

One thing is I have little to suggest about hands on. Maybe the crystal radio, but have each one of them do one or a class project ? It would be nice to do something. I just can't really think of much that will not take up too much time.

Nother thing, will you have a budget for materials ? If you can spend OPM maybe some perfboard, a few transistors and little elcheapo speakers and they can build a small amp. I don't know. And that is not good because I always had a hard time learning in the abstract. Real world always worked better for me.

Maybe in conjunction with the crystal radio, build a transmitter ? You do that, but do it on a breadboard. Use the scope to demonstrate what it is doing to the carrier and then put the scope on the receiver.

Actually if you build the transmitter you won't need a long wire for the antenna. You don't really need to demonstrate how to get WIXY 1260, (was a very popular AM rock station before FM took over) you are demonstrating the principle.
 
On 12/4/2015 1:32 AM, ABLE1 wrote:

I would like to contribute to the thoughts on starting an
electronics/electrical course. May I be the first to say that the story
you are about to read really happened. I would strongly suggest that
the circumstances never be repeated since it could have gone a totally
different way, as most here would/should agree.

The year was 1965. The school district decided that they should start a
Basic Electrical/Electronics course to offer to those students that
signed up. (it was the beginnings of Vo-Tech). So, they emptied out a
storage closet in the High School and moved in a bench with a
wood(maple) panel box about 6 feet long that had, powerstats, volt
meters, amp meters sockets, connectors and test cords, etc. It was
really COOL.

About 10 senior guys signed up for the new course, me being one of them.
The instructor was the wood shop teacher. Who by the way had sawed
off the tip of his thumb (twice). While demonstrating how to use a
band-saw the first time. And demonstrating how he did it the second time.

On the very first day of class the instructor explained what the course
was about, etc, etc. He then said we could do a practical demonstration
of electricity. He asked for a volunteer and the 9 other guys stepped
back one step.

The demonstration would be for me to hold two probes that were patched
into two sockets as well as to volt meter. The instructor told me to
hold on as long as I could and he would shut it off when I told him. He
then started to turn the powerstat up from zero. As he rotated the
voltage meter increased. At 25vac no effect. At 30 to 40 vac I started
to feel a tingle. At 60 vac my arms and hands started to shake. At 75
- 80 my hands started to rotate inward and at 90 vac I said OK that's
enough. He then backed off on the powerstat and then rotated to max
100% against the stop. It was at this point that I came off the stool
and jumped back against the wall pulling the leads out of their sockets.
Everybody got a good laugh. As I was catching my breath the class
bell rang and it was off to Spanish II class (which I failed, but that
is another story).

What is the lesson here?? Listen to your elders and don't do dumb stuff
like we did!!

Have a nice day.

Les
Click to expand...
That reminds me of another real high-school incident that took place
that very same year (1965). Most homes in my town didn't have
electricity then. Our teacher of basic physics brought a 90-volt radio
battery to class and, to demonstrate that while high voltages are
dangerous, lower voltages aren't, he pinched a terminal in each hand.
Then one wise guy told him to touch both ends to his tongue. He did, and
nearly cracked the blackboard with the back of his head.

We didn't dare laugh out loud but there was plenty of tittering.
 
Yup, and today there would be a lawsuit and some group calling for the teacher's head and possibly an act of congress.
 
On 12/8/2015 7:43 AM, Pimpom wrote:
On 12/4/2015 1:32 AM, ABLE1 wrote:


I would like to contribute to the thoughts on starting an
electronics/electrical course. May I be the first to say that the story
you are about to read really happened. I would strongly suggest that
the circumstances never be repeated since it could have gone a totally
different way, as most here would/should agree.

The year was 1965. The school district decided that they should start a
Basic Electrical/Electronics course to offer to those students that
signed up. (it was the beginnings of Vo-Tech). So, they emptied out a
storage closet in the High School and moved in a bench with a
wood(maple) panel box about 6 feet long that had, powerstats, volt
meters, amp meters sockets, connectors and test cords, etc. It was
really COOL.

About 10 senior guys signed up for the new course, me being one of them.
The instructor was the wood shop teacher. Who by the way had sawed
off the tip of his thumb (twice). While demonstrating how to use a
band-saw the first time. And demonstrating how he did it the second
time.

On the very first day of class the instructor explained what the course
was about, etc, etc. He then said we could do a practical demonstration
of electricity. He asked for a volunteer and the 9 other guys stepped
back one step.

The demonstration would be for me to hold two probes that were patched
into two sockets as well as to volt meter. The instructor told me to
hold on as long as I could and he would shut it off when I told him. He
then started to turn the powerstat up from zero. As he rotated the
voltage meter increased. At 25vac no effect. At 30 to 40 vac I started
to feel a tingle. At 60 vac my arms and hands started to shake. At 75
- 80 my hands started to rotate inward and at 90 vac I said OK that's
enough. He then backed off on the powerstat and then rotated to max
100% against the stop. It was at this point that I came off the stool
and jumped back against the wall pulling the leads out of their sockets.
Everybody got a good laugh. As I was catching my breath the class
bell rang and it was off to Spanish II class (which I failed, but that
is another story).

What is the lesson here?? Listen to your elders and don't do dumb stuff
like we did!!

Have a nice day.

Les

That reminds me of another real high-school incident that took place
that very same year (1965). Most homes in my town didn't have
electricity then. Our teacher of basic physics brought a 90-volt radio
battery to class and, to demonstrate that while high voltages are
dangerous, lower voltages aren't, he pinched a terminal in each hand.
Then one wise guy told him to touch both ends to his tongue. He did, and
nearly cracked the blackboard with the back of his head.

We didn't dare laugh out loud but there was plenty of tittering.
Click to expand...

WOW!! I know the buzzz one gets on a 9-volt battery on the tongue.
I would think that 90-volts would have to leave a scar or worse.
It would seem that some teachers of the era were still learning.

It was a different time.

Les
 
On Thu, 03 Dec 2015 00:08:54 -0500, Ecnerwal
<MyNameForward@ReplaceWithMyVices.Com.invalid> wrote:

I'm contemplating offering a basic, assume nothing electronics course
during the "winter-session" at our school. 17 meetings over 5 weeks
totaling about 40 hours.

I want to offer basic concepts and hands-on, use a soldering iron, make
stuff. Without treating it as magic, I'm also facing the fact that
there's no assuming that the students will have had any advanced
mathematics, so I'm going to need to step away from messy math and stick
to simple stuff and the occasional "you'll learn more later."
Click to expand...

Kids love LEDs. A few LEDs, batteries, resistors, clip leads would
start some instincts for current and voltage and resistance. Maybe
sneak in a DVM.
 
On Tue, 8 Dec 2015, John Larkin wrote:

On Thu, 03 Dec 2015 00:08:54 -0500, Ecnerwal
MyNameForward@ReplaceWithMyVices.Com.invalid> wrote:

I'm contemplating offering a basic, assume nothing electronics course
during the "winter-session" at our school. 17 meetings over 5 weeks
totaling about 40 hours.

I want to offer basic concepts and hands-on, use a soldering iron, make
stuff. Without treating it as magic, I'm also facing the fact that
there's no assuming that the students will have had any advanced
mathematics, so I'm going to need to step away from messy math and stick
to simple stuff and the occasional "you'll learn more later."

Kids love LEDs. A few LEDs, batteries, resistors, clip leads would
start some instincts for current and voltage and resistance. Maybe
sneak in a DVM.

And it so much better now than when I was a kid.
Click to expand...

The LEDs are much brighter, you can get them cheap without being floor
sweepings from PolyPak or wherever, and they also come in blue and white,
unlike back then with red, orange and green.

Michael
 
Ecnerwal <MyNameForward@replacewithmyvices.com.invalid> wrote:
But I can't really see trying to force feed AoE (though I still like
it) to high school students (nor make them buy it for a 5 week course
that won't work far into it.)
Click to expand...

A little before I got into high school, I got a copy of this book:

http://www.amazon.com/Getting-Started-Electronics-Forrest-Mims/dp/0945053282

Mine was from Rat Shock, but now you can get it online. Anyway, it
might qualify as a "lower speed" version of AoE. It starts out with
the theory, and then discusses different kinds of components, from
resistors and capacitors up to op-amps and TTL/CMOS digital ICs. The
back several pages have project circuits to build.

Standard disclaimers apply: I don't get money or other consideration
from any companies mentioned.

Matt Roberds
 
"George Herold" <gherold@teachspin.com> napisal w wiadomosci
news:9efd93a6-7d7e-425a-b9ff-bb8a988eaee5@googlegroups.com...
For the fun part I also like the AM radio idea.
Click to expand...

In the circuit the electrons can flow from the ground into the antenna only.
https://en.wikipedia.org/wiki/Crystal_radio#mediaviewer/File:Simplest_crystal_radio_circuit.svg

Why and for what?
S*
 
On Friday, December 11, 2015 at 3:39:38 AM UTC-5, szczepan bialek wrote:
"George Herold" <gherold@teachspin.com> napisal w wiadomosci
news:9efd93a6-7d7e-425a-b9ff-bb8a988eaee5@googlegroups.com...

For the fun part I also like the AM radio idea.


In the circuit the electrons can flow from the ground into the antenna only.
https://en.wikipedia.org/wiki/Crystal_radio#mediaviewer/File:Simplest_crystal_radio_circuit.svg

Why and for what?
S*
Click to expand...

I'm sorry do you have a question about that "simplest" radio circuit?

George H.
 
On Tue, 08 Dec 2015 00:21:33 -0500, Ecnerwal
<MyNameForward@ReplaceWithMyVices.Com.invalid> wrote:

Well, I put a course description out there, we'll see what I get for
interest in a couple of days.

Have scope, (and a couple of less-likely scope-shaped objects_) have
counters (through I don't know that I'll use them), have multimeters,
have an AADE L/C meter, have a millivolt potentiometer with standard
cell (so retro...) have analog meters, have various irons and a hot-air
rework station.
Click to expand...

[Shameless plug:]

If you have a Windows system available and need a signal
generator, please consider Daqarta. The signal generator
(and most everything else except signal *inputs*) keeps
working after the trial period, so it's absolutely FREE,
forever.

Standard waveforms include sine, triangle, ramp (with
adjustable slopes), square, and pulse (with adjustable
bipolar phases and amplitudes). Also creates uniform,
Gaussian, pink, or band-limited noise. In addition, it can
create arbitrary waveforms that you define, or play an
existing file repeatedly as the signal source.

You get up to 8 independent "streams" (which can be separate
output channels if you have a multi-channel sound card...
under $30). Each can be independently modulated via Burst,
AM, FM, PWM (or Phase Modulation), or frequency Sweep.
Streams can be used as modulation sources for other streams.

A real-time display shows the waveform(s) and you can sync
to the modulation source... handy for showing stable FM
waveforms, for example.

If you have any particular experiment or demonstration in
mind, I will be glad to assist.

Best regards,


Bob Masta

DAQARTA v8.00
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, Pitch Track, Pitch-to-MIDI
FREE 8-channel Signal Generator, DaqMusiq generator
Science with your sound card!
 
"George Herold" <gherold@teachspin.com> napisal w wiadomosci
news:72af7517-cbe8-4f5b-9c89-ff8ffc2c35f5@googlegroups.com...
On Friday, December 11, 2015 at 3:39:38 AM UTC-5, szczepan bialek wrote:
"George Herold" <gherold@teachspin.com> napisal w wiadomosci
news:9efd93a6-7d7e-425a-b9ff-bb8a988eaee5@googlegroups.com...

For the fun part I also like the AM radio idea.


In the circuit the electrons can flow from the ground into the antenna
only.
https://en.wikipedia.org/wiki/Crystal_radio#mediaviewer/File:Simplest_crystal_radio_circuit.svg

Why and for what?
S*

I'm sorry do you have a question about that "simplest" radio circuit?
Click to expand...

Yes.
Such radio works perfectly close to AM mast.
Students should know what the electrons are "doing" in such circuit.
S*



---
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https://www.avast.com/antivirus
 
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