By Mark Julicher
Compared to language or mathematics, the study of electricity is very young; however, the subject of electricity is vast and still growing. It may seem a daunting task to teach electricity in your homeschool, but take heart! With a good starting point and some definite objectives, you can introduce this fascinating world to your students.
Can I teach my children about electricity?
Can I teach it safely and economically?
The answers are, “Of course, you can teach electricity”, and “Yes, you can do it safely and economically.”
So, what should be your objectives and where should you start? An elementary student should be able to find out the important points about electricity: what it is, what are its properties, what makes it, and why is it dangerous.
Your older student will want to do and learn more about electricity, control, and measurement. Electrical safety should be a major concern for your home as well. Studying this topic from a text may yield a lot of facts, but will not impress upon your children the dangers of using electricity. They will also need to learn about consuming electricity, conserving it and measuring, not to mention paying for it. When taken all together, you now have a list including safety issues, some theory, and practical consumer objectives; all that is necessary to become an informed user.
A good place to begin your study of electricity is its history. Some of the classic experiments done by Tesla, Volta, Marconi, Franklin, etc. are amazing and also dangerous. It because of Franklin that we know how to protect against lightning. It is because of Edison that we know how to make effective storage batteries. I don’t recommend repeating some of their experiments at home unless you are good friends with the local fire department. Read about these historical figures and their work, and then move on to your own investigations.
Next, you should look into the question of what electricity is. We can see evidence of it, use it to accomplish work, and even die from it if we mishandle it, but most people do not understand its nature. The best way to begin to study electrons and their movements is to play around with static electricity. We all have experience with generating a charge on a dry day and then getting zapped when we touch the doorknob. We also know that a balloon will attract hair. If your child understands why static electricity builds up and discharges, he will find understanding the current or flow of electrons much easier.
After checking out the possibilities of static electricity, then it is time to move on to electrons moving in a current. Direct current and alternating current are each very useful in our daily lives and so your child should understand them; how they are generated, how controlled; and how used at home. What are the different kinds of batteries we use and how do they produce electricity? What are the other ways to produce electrical current? Solar power, wind power and geothermal power, not forgetting hydroelectric power, are all ways in which we generate electricity.
Electricity is a ready servant. We are surrounded by complicated electrical technology that is growing rapidly. Great advances are made every year making it almost impossible to know all there is about electricity and electronics. But, our children can become informed users who can control this servant wisely and not be intimidated or overwhelmed. What, then does an informed user know about electricity? He/she knows how many ways electricity is used in the home, how much electricity costs, and understands electrical safety. Finally, your student should know how to take care of the electrical servants around the house. Is this starting to sound easy? I hope so. It is still a BIG topic, but we starting to get our arms around it now!
Let’s look at the four issues; uses, cost, safety, and care more closely.
How many ways do you use electricity around your house? You could walk around with your student while you make a list. This could take a while and it should generate a zillion questions like: why is there electricity going to a gas furnace, why does the phone work when the power is out, why do the lights dim when the refrigerator comes on, why are there so many fuses or circuit breakers behind the electrical panel. Why is the dryer plug shaped differently than most of the others, why are there three electrical wires coming to the house when there are only two wires leading to the lamps and TV…the list of questions goes on forever.
Take one question and research it! Write a good paragraph or three stating the question and the answer. What a good starting point!
When you did your list did you remember the battery in your car? Did you remember the dry cells in the flashlight? How about the TV remote control or the garage door opener? How about the electrical energy beamed to your house in the form of radio broadcasts? Wow, so many starting points!
How much does your electrical servant cost? Can you explain the electrical bill to your students? Can you teach them to read the power meter especially the tricky old ones where some of the dials move counterclockwise and clockwise? Can you predict the amount of your next electrical bill? Can you show them how the dial spins faster when high wattage lights are on? Can you turn off everything unimportant in the house and see how slow the meter turns?
Is this an economics lesson? You bet it is! While you are teaching the cost of having your electric servant, don’t forget the cost of things other than house current such as car batteries, flashlight cells, solar panels, wind generators and more. Could you run your house on car batteries, why don’t more people have solar powered appliances, why are alkaline batteries cheaper to use than regular batteries?
Oh, my! That was another string of questions begging to be answered by your student. It was also another possible set of starting points.
The next issue to explore is safety. You know a great deal about electrical safety. You may not understand all that you know, but you know a lot. For example, you know not to use electrical devices while standing in a puddle of water or in a bathtub. Teach this to your student! A young man was killed recently when he plugged in a car battery charger while standing on wet grass. How tragic! You know that you never put a knife in the toaster to retrieve your burnt bread, but that a clever toast lifter made from two tongue depressors can be safely used. This brings up the topic of insulators and conductors. How about a list of conductors and insulators? How about a list of things that should never go in the microwave oven? And why?
Oh, did you remember that microwaves (not the ovens) are an electrical energy field? Good. It is just another form of your electrical servant to be used correctly.
You can’t stress electrical safety enough. Batteries give off explosive gases when they are charged. Halogen lamps give off large quantities of ultraviolet light and can damage eyes if not filtered. Heat lamps can cause sunburn. Electric motors give off tiny sparks and can set flammable fumes on fire so don’t use the electric weedchomper near the gas can. Wet skin conducts much better the dry skin. Don’t pull out a plug by the wires; don’t put too many plugs into an extension cord. Don’t put a penny in the fuse box. The TV still has deadly voltage inside it long after it is turned off. Improperly handling a spark plug wire on a running engine can knock you silly – even on the lawnmower.
Once again, the list of safety items is very large. Moms and dads may not remember or understand all the safety rules, but what a great list of library research topics.
Let’s move on to the last of the four issues, care of our electrical servant. Actually, this topic is both care and respect. Used properly, electric appliances last a long time and work safely. Abused appliances do not last as long and may not be safe. It is good to discuss examples of abuse and the consequences.
Examples might be that overloaded motors will overheat and eventually burn out. Overloaded extension cords get hot and can start a fire. Rotating devices such as blenders, mixers, and garbage disposals can be damaged by feeding them spoons and other objects. Plugging in or unplugging sensitive devices while they are switched on can damage them. Sparking the cat’s nose on a dry winter day can cause cat bites. Pulling out electric cords by the wire can break wires or cause short circuits. Turning the TV on and off a while lot of times quickly will most likely destroy it. And finally, if the device says, “no user serviceable parts inside,” it really means, “don’t mess with it unless you intend to buy a new one.”
Did I answer the question about where to start? You can start nearly anywhere and get the vital concepts across. Safety leads to care and respect which leads to uses, which leads to costs and so forth. It really does not matter where you begin to teach the fundamentals of electricity as long as you keep the objective in mind. You want an informed user of the servant electricity.
Once this foundation is built, the student can go as far as the imagination will allow.
A few parting thoughts.
Many people like a list of concepts, topics and projects that provide a good coverage of a topic. After giving this some thought, I have compiled a brief list that a senior high student should understand. This is not to say you should wait until the senior year to teach electricity. Most students can grasp electrical concepts much earlier and can be working with the basics by age twelve. By age thirteen, every student should have built and explained one simple electrical device such as a buzzer or electromagnet. It is better to make a simple device that is understood than to build a superwhizbang gadget which the student cannot explain. Students who enjoy electronics will naturally build more. Other students will become wise users of electricity.
Concepts which your students should understand:
- Static electricity
- Alternating current
- Direct current
- Ohms Law
- Voltage
- Ground
- Resistance
- Digital signal
- Analog signal
- Battery
- Cell
- Transformer
- Electromagnet
- Circuit
- Electron
Resources:
Simple Machines Made Simple by Ralph St. Andre. A great book for experimenters, Simple Machines Made Simple not only has easy to understand directions and down to earth experiments, but there is plenty of follow through. The students are asked to observe, record, measure, and even make line charts! The activities are suitable for 3-8th grades and also include directions for making an activity center so the kids can work independently.
Basic Electronics by Gene McWhorter and Alvis J. Evans. This book is really a textbook. It is divided into chapters covering the basics of electronics, DC and AC electricity, diodes, transistors, amplifiers, radios, digital circuitry (the foundation of computers) and more. The chapters are organized and should be able to be used easily independently. There are problems to solve and quizzes.
Getting Started With Electronics by Forrest M. Mims III. This book is full of easy to use electronics experiments that make sense. My son started this one at age 8, as it is simple to understand. The concepts are real, not watered down and progress to college level very quickly even though the apparent difficulty of the book is very low. Buy it! Highly Recommended.