So.. My sister is an elementary teacher. She saw an amplifier I just finished, and asked if I could make a simlpe ciruict to show to her kids, and explain the basics of how it works. I was looking for something like a LED caculator. Maybe something that could add by push buttons then shown on LEDs. Maybe just reset by a switch or something. I checked this post about a 7-segment LED Counter, and thought something more interactive would be better. If anyone had any other ideas that would be simple, and somewhat easy to understand that would be great.

 

What grade are they in? I think explaining 555's to almost any elementary school student would be a tall order. Maybe you could rig up a few full adders using a handful of logic gates? It would still be a lot for them to comprehend, though.

 

If you'd like to start with something simpler, you might consider something like my daughters 4th grade Science Fair project. I helped her build a giant 2 foot seven segment display into one of those large paper covered foam project display boards. The segments were clearly marked 'A' through 'G' and there were seven toggle switches mounted which had corresponding 'A' through 'G' labels. The seven segment display cut-outs were covered with red plastic on the back of the board and 'V' shaped white cardboard reflectors with a pair of 6 volt panel light bulbs were attached with tape to cover each segment cut-out. A 6 volt lantern battery was connected to the switches and light bulb wiring on the back of the board.

My daughter described the concept and then had her classmates design a "truth table" for characters "0" through "9" and test their design using the switches on the display.

 

thats a good one mike, that how i got my son interested in electronics (he was 8 at the time) only using standard 7 segs (2' tall ones would have been awesome)

i draw 7 seg outlines on a bit of paper, and got him to colour in the segs to write his name, then using the chart a=pin 1, b=pin4, ect he made up his name on breadboard, then we moved on to making it flash using basic electronics (the two transistor flashing circuit everyone learns at some stage)

on the same line you could build a big (cos kids like big, and they look more fun) logic simulator. the one with a basic grid. with big mushroom head buttons on the left(inputs) and nice big lights on the right(outputs) where you can put any one of the logic gates in the middle, and it shows its fuction, kids can come up and press the buttons ect, learn the truth tables.

for the logic bit - i would build a circuit and mount it behind the display with all the logic built in, and use a series of PEGS mounted in differing patterns on the back of the large 'logic gate', where the peg would hold it on the board but at the same time, the pattern would tell the logic board what it was to simulate ( i guess you could rfid, or any hundreds of other methods to identify the current 'logic gate') i would also use rope lights as the connection between the switches, and the logic, and the output, that way the kids can see which wires are HIGH (lit) or low (Not lit).

i know this is a terrible description, but if you understand any of it, and are interested in this idea then let me know and i'll draw you some pictures to make it clearer.

 

this is a VERY basic drawing of what i mean. you would use rope light, with 1/4" stereo jack plugs on the ends. (2 conductors for the ropelight, 1 for the signal) to connect between the gates.

this lets you do simple 1 gate circuits to explain how each gate works, and also up to 4 gates to build basic circuits to show how they work together.

I imagine it in brightly painted MDF, and i like the idea enough that im gonna build one myself and see if its any use to my kids school. As i know for certain that at the school i attended thay never placed enough enphasis on technology, and it is the way of the future.

EDIT: just noticed that i forgot to put the 1/4" jack sockets on the drawing next to the output lights

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Snap Circuits seem popular for the younger crowd.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com/

 

How about a persistence of vision demo? Start with any multiplexed display and make the scan rate adjustable via a pot. Then the kids can see how a rapidly updated display appears to be continuously lit.

 

That's a good one!!!

 

If you can work out how to make one, you could amaze them with an electronic magic trick such as the "Magic Switchboard".

Each coloured switch always lights the same colour lamp even when the lamps are switched-around.
See a video on this web page:
http://www.alakazam.co.uk/acatalog/G...Magic_27_.html

Perhaps it could be done with a microcontroller and it may work by the microcontroller and the magician memorizing the sequence in which the bulbs are inserted so that he then operates the corresponding switches in the same sequence?

It gets much more complex later though when he swaps the coloured switch caps, I have no idea how that part works.

 

is your sister single? jk man.

today i assisted IEEE in judging a 4/5 grade science fair. the event organizer, built a Dc motor composed of two DD batteries, two 6lb- force disk magnets, coiled rotor and copper electrodes. very simlpe design, fun and interactive.

anything more or less and kids will start throwing paper spit balls, i, taking the lead of course.

 

If you watch the video again, you should be able to work out how the magician tells the circuit which order the lights are in. Hint, look at the order the lights are illuminated. I might just have to build one of those.

Mike.

 

Neat trick but the price is a shocker. The logic is very simple.

 

Pretty neat, if I could find a magic store to sell them I'd build a few.

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com/

 

Thanks everyone for the input on this.

Actually she's getting married in June, but I'm sure she would still blush lol


lol

Bill, I showed her the snap circuits you were talking about, and now she's ordering one for her class. Great idea thanks.

I've built a simlpe electric motor for her to show her kids, and I think I'm going to give the adjustable multiplexed display a try(I'm still learning too) Maybe I'll use a few other things to show ac and dc using a fan. That's what I remembered getting me interested in electronics when I was young.

 

sounds good. yeah don't build anything to complicated or possibly boring.

i liked the motor idea, becoz it was simple, fun and everyone got involved. plus its chea and they can probably take the motor home.