A Wire Maze With an Electronics Twist

Here is a SIMPLE and really FUN electronics project you can make at home. You don't need to make a printed circuit board which makes everything a whole lot easier!

I'm sure you've played the "Wire Maze game"...(also called "Sammy the Snake" by shop teachers in our district... ) You thread a wire loop through a maze. A few years ago I built a simple latching circuit that would light (and keep lit) an LED if you touched the wire with the loop. Kids liked it but they were not thrilled by it so I added a ZAPPER in the handle. I also built in a switch so the kids can toggle between a light or a zap. 
Oh ya.
Now the kids are SO excited i keep this project for last as a reward for doing a good job in the other shops! 

I've been teaching electronics for 14 years and i have tried every kind of board making method out there. I used to use the photo-resist method which worked well but became tough to do in large amounts...and expensive! I've also tried the laser-copier paper and the toner transfer paper which work fairly well. The REAL problem is the chemical part of the process. Making a copper board means that the uncovered copper needs to be chemically removed. Big pain. Big mess. Kids in grade 6,7 and 8 with nasty chemicals just sucks.

So enter the method that electronics teachers scorn. Wood, nails and point to point wiring. I scorned this method as hokey and hack until i started using it with my students. THEY LOVE IT!! Hammering and soldering nails with parts attached is just so cool the kids are excited about it. The other advantage is that it is really easy to troubleshoot... problems are obvious! No chemicals, cheap, kids love it and easy to work with. TRY IT!

This instructable is designed as a day to day lesson plan outline for teachers but i think what makes this project excellent also is that you can easily make it at home!

Learning Objectives:
-The students will learn to identify and install basic electronic components including the resistor, SCR, transformer and LED.
-The students will learn about electromagnetic induction and a latch circuit. By understanding these concepts  the student will than be able to analyze and troubleshoot the circuit.
-The student will learn to use a soldering iron safely than apply the skills to build a circuit.
-The student will design a game piece than apply the design to build it.

New Vocabulary To research:
-Polarity
-Circuit
-Insulator
-Conductor
-Toggle
-Latch
-Amperage
-Voltage

Materials: (per student...)
-220R, 1K 1/4watt resistors. 
-5mm LED (any color)
-SPDT slide or toggle switch.
-SCR 106B (220 package)
-Transformer MODE 60-282-0 (small green one)
-3 feet of 18-22 Gauge hookup wire. Non stranded...
-30 brass nails... about 5/8" long (or W.H.Y.)
-Block of softwood about 3/4' thick, 3" by 5"
-Solder... i use the 1.2mm rosin core.
-1/16" welding wire (or coat hanger thats been sanded)
-2 small pieces 1/2" by 1" copper clad 1 sided.
-epoxy or double-sided tape.

i find the best place for parts is often DIGIKEY. try them at digikey.ca. They will ship for cheap depending on how much you buy and it is often the next day. VERY FAST.  You can also use that old-fashioned device called the telephone and talk to a real live person who is usually very friendly. Heres a few parts numbers to get you started...

-220R resistor is  CF14JT220RCT-ND (digikey)
-1K resistor is  CF14JT1K00CT-ND (digikey)
-SCR is C106BGOS-ND (digikey)
-transformer is a mode product... electrosonic (http://www.e-sonic.com) has it for $2.50 
-copper clad PC94-ND (digikey)
-LED 516-1335-ND (digikey)
-SPDT switch 450-1569-ND (digikey)

There are all sorts of  distributors for electronics on the web.. digikey, electrosonic and mouser are all great. Most of the resistors will be a minimum of 10-25 which is still only $3... the switch and transformer are the most expensive at $2.50... pretty cheap!

Tools:
-Sandpaper 120Grit
-Soldering pencil (iron) about 25 watts...
-hammer
-Drill and 1/16" bit  (bigger if you use a coat hanger)
-needle-nose pliers, wire strippers

Submitted by HD Stafford Middle School  for the Instructables Sponsorship Program

Step 1: Prepare the Circuit Base

The drawing above is for the circuit... If you print it out it should be about 2 1/2" long. It really doesn't need to be accurate as long as the transformer wires can reach and the nails for the switch don't touch each other... They should be about 1/8" apart. This really is not an accurate layout which is the beauty of it because really is doesn't matter. Kids can make it... badly... and it will still work!

What i do is photocopy the picture 6 times, cut the pictures out, arrange them on a piece of paper than photocopy it 12 times. You'll have enough for 2 classes!

Cut out the wood for the students unless the kids are in woodworking and can do it themselves... You'll need 1 block per student... 1" thick (approx) 3" by 5". Use a softwood that is fairly clear. Knots make hammering tough for the kids. You need to drill a 1/16" hole on each end. Check out the photo.

Cut out the paper nail and wire drawings from above than show the kids how to nail a brass pin into each small circle on the drawing. Some kids have a hard time with this so you could arrange them in pairs. One student can hold the nail with a needle-nose pliers while the other hammers the nail in.

When all of the nails are in, flip the block and gently hammer from the bottom so the nails are all fairly even.

Comments

[RangerJ]

I like it. Good job.

I taught security electronics in school for a while, and I just used washers/screws on a breadboard. That worked fine, although not as nice looking as yours.

[nhormell]

hey im working on one of these for a school project
can you tell me if this transformer will work

http://www.mouser.com/ProductDetail/Xicon/42TL003-RC/?qs=sGAEpiMZZMv0IfuNuy2LUd1oaj1xuSl7ovuhlClV6Fw%3d

[salty58]

can you please tell me the pin order of the scr from the line diagram i have it as
K A G .This is looking left to right from the switch.You mentioned connecting pin 1 to battery negative using the switch is pin 1the cathode.and is pin 3 the gate the furthest from the switch .THANKS FOR ANY REPLIES

[nowuknowjack]

Great 'ible...my son is leading a 4-H electronics project and is using this as one of the classes but we need help locating the transformer. Been searching Electro sonic and no luck. Do you have a part number? Does digikey have it? We tried hacking the transformer out of a Kodak disposable camera but no luck...BTW have you ever hacked a disposable flash camera...there is a whole mini electronics lab in there BUT be CAREFUL of the capacitor...OUCH!

Your 'ible reminds me of a cartoon I once saw of a convict in an electric chair with one of these wire mazes!

[bvisser]

Just built eight of these with my middle school class; Radio Shack has an audio transformer for a little less than $3 that worked fine.

[stumitch]

you wouldn't have a part number would you? it would be good to know about a reliable source!

[bvisser]

Sure; Radio Shack part 273-1380, $2.69
http://www.radioshack.com/product/index.jsp?productId=2103254

[stumitch]

I was fool enough to try a class of zappers using the disposable cameras. NOT smart to have 24 grade 9 kids running around with high voltage capacitors! :-)
I had a similar question about the transformer when i first posted the 'ible... here's a link to the e-sonic site...
http://www.e-sonic.com/acc/products.aspx?partID=60-282-0&partIDExt=279&command=detail
have fun!
-stu

[Jinxedsoul]

I remember 10 years ago (it was your 2nd or 3rd years teaching electronics) in your class when we made Tazers with car ignition coils... or the mini Tesla coil that you made us take apart after it attacked a kid who was drenched in sweat, sending his dripping wet Slurpee flying across the room (the inter-webs need not worry the kid was fine just a little shakin up ;P).
Needless to say the following year was a lot more tame. ROFL
School was a very crap time in my life but memories of your electronics classes always makes me smile and feel all warm and fuzzy inside kinda like those tazers made you feel after a good shock! lol

[Jinxedsoul]

Just want to point out stu is a great teacher and he cares greatly about the safety of his students, said mini Tesla coil device was made on our lunch break with out him knowing what we were really building :p

[bvisser]

Saw your Instructable just as I was getting ready to teach electricity to my middle schoolers; switched to using your project as the basis of our learning, and they had a great time. Of the eight boards made (student pairs), about half had no problems, a couple had a problem or two they were able to diagnose, and the last two just required some serious thought (and continuity testing). Easy project, students got to use one new power tool (soldering irons count, right?), and numerous parents were "shocked" at their children's electronic prowess when they came home. Thanks!!!

[stumitch]

Great! thanks for the feedback. always good to hear that people are trying it out with classes. Trouble-shooting is always a challenge and almost always come back to a soldering joint that LOOKS good but isn't. :-) glad to hear it worked for you!

[iApple guy]

This is great work. You have my vote!

[stumitch]

excellent! thanks for the comment!
-stu

[enovoa]

WOW so you're an electronics teacher? Could you explain me (detailed or not, it's up to you) how do transistors work? I'm learning electronics and I'm having a hard time with these little fellas

[stumitch]

hummm.... well... i go too simple for some people maybe but i usually start with the picture of a normally open switch. if you push the crossing line down it closes the circuit and current flows. I get all goofy and pretend to try and push it 1000 times a second... which is a limitation of a mechanical switch... so i ask what if i had an electrical way of pushing it down? so i draw a line pushing down... i than draw a circle around it and an arrow to show the flow of the electricity and voila you have a schematic symbol of a transistor. i get into a variable power flow depending on how hard i push to link it to amplification.... a waveform... i also suggest that just a tiny little push can allow tons of power to flow through the switch. i suggest that a tiny battery could control a transistor (if it was big enough) which in turn could control the power for the whole school. kids like that idea.
i hope this gives you an idea... try it with drawing pictures... it makes more sense :-)
-stu

[enovoa]

Thanks for your explanation. I never thought of you answering this fast LOL. So basically I can think of the job of a transistor being similar to a 12v car relay? Relays can switch on or off a circuit being driven by a small current and can be used to "amplify" a signal... but a relay is a coil switch. Transistors work a little different the way I see it.

[stumitch]

you're right... they do a similar function as a relay and you're also right about it being different... ya, totally different! :-) but the idea of a small amount of current controlling a large amount is the main idea i want to get across to kids.

[andrewgilmartin]

Would you recommend an alternative transformer to the MODE 60-282-0 (small green one)? I am having a hard time finding one of these from a supplier in the US. Thank you.

[stumitch]

i did a search "mode-60-282-0 equivilant" and drilled down until i hit this..
http://ca.mouser.com/Search/Refine.aspx?Keyword=42TU003-RC
its from mouser which is a great supplier and they have it in stock.
have fun!

[joerice01]

Your circuit making reminds me of the very early breadboard.

[emerson.john]

This is good work. You get happy kids, they learn how things work - they even learn why it is called bread boarding! You have my vote.

[nh4x4Jeep]

Instead of the transformer, you could add a brutally loud Piezzo buzzer, which ALWAYS gets your attention, startles you, and almost has the same effect as the transformer!

I was heartbroken years ago when Radio Shack got rid of the bulk of it's electronics (AND it's catalog!!!). It's GREAT to see others making electronics fun! Kudos to you for your work with kids! And thanks for sharing this instructable!

[stumitch]

YA! i've heard some of the ultra-loud ones on safety devices. pretty startling! thanks for the comments... and yes i feel the same with radio shack... i used to love prowling around in the back as a kid looking at all the cool bits and pieces. at least now we have mouser and digikey. :-)
-stu

[danm95]

You could make this a pretty sinister device if you used a handcuff and used the key on a key ring as the handle.

[stumitch]

I've updated the parts list to include digikey numbers to make buying all the goodies quite easy...

[WYE_Lance]

This is fantastic! Really the perfect project to get kids excited about circuitry and introduced to a soldering iron. Good luck in the teacher contest!

[stumitch]

Much appreciated! thanks for the comments. I really have fun doing this project with kids. They learn TONS without even noticing it.. :-)

[WYE_Lance]

Yep, exactly - I do a lot of hands-on projects with kids and I joke with the parents that it's kind of a secret that they're actually learning a lot!

[TRINIGURU]

Super Project >>>>>> would be hilarious if an audio option for "Hangaroo like" effects could be added.
Would definitely build this THANKS

[stumitch]

listening to the kids shriek when they get zapped is such a funny soundtrack :-) whats really funny is that they KEEP doing it... thanks for the kind words everyone!
-stu

[Grand-Pa]

That's a great project. Loved reading through it.
Where were you when I went to school. oops you weren't born yet.
We still had fun in shop class tho even if we had to make our own.
Thanks for sharing.