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.
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!
-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:
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!
-Soldering pencil (iron) about 25 watts...
-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.