Organic Rankine Cycle
Waste Heat to Power ORC search was updated real-time via Filemaker on:Waste Heat to Power ORC | Return to Search List
Search Completed | Title | Electricity for Dummies, Part 1
Original File Name Searched: HP44P62.pdf | Google It | Yahoo | Bing
Text | Electricity for Dummies, Part 1 | 001
Electricity for Dummies, Part 1 Dan Lepinski
©1994 Dan Lepinski We use it but we can’t see it. We
store it but we can’t touch it.
It’s an integral part of life. For most of us, electricity is one of the least understood forms of energy. Tired of being in the dark? Want to know more?
Loosen your seat belts, folks. We’re about to take a slow, calm journey into the electric world of Dr. Demento. What!? You’re not familiar with electricity? You’re not a rocket scientist either? Not to worry. This is one time where you don’t have to be. No techno-jargon here. Just plain everyday words. With each visit, we’ll discover something new about this strange thing called electricity. All you need is imagination... and a desire to learn.
Introductions and Analogies
Hi! The gang at Home Power Central calls me Dr. Demento. Why? Probably because I learned about electricity the hard way. My electrical career began as a youngster. Perhaps out of curiosity, I inserted a stray hairpin into an outlet. Sparks flew. Surprised but undaunted, I wanted to learn more about this strange creature that lived in the wall. I didn’t understand it at first. The big words were confusing. In self-defense, I developed “mind pictures” to help relate the bewildering aspects of electricity to everyday life. Most people call these mind pictures “analogies”. Not sure about analogies? They’re easy! You’ll like them. I use them frequently.
What is it? A magic potion inside batteries? Some weird substance hiding in wires? Neither. And both. Electricity is simply a type of energy. Like light. Or heat. Electricity comes in three basic flavors; 1) the kind that just sits there (“static” electricity); 2) the kind that moves only in one direction (“Direct Current” or “DC”); and 3) the kind that moves back and forth (“Alternating Current” or “AC”). Eventually, we’ll spend most of our time on the back and forth or “AC” variety. To do that, we’ll have to discuss the other two flavors first.
“Static” electricity? As used here, “static” means “not
moving”. Under the right circumstances, it has the ability to perform work. For now, it isn’t. Time for our first analogy... Let’s start with a balloon. Pretend you’ve inflated it but haven’t tied the end. As long as you hold the end closed, the balloon doesn’t move. The air inside is like static electricity. It has the ability to do something. It’s just that it hasn’t - yet. Now release the balloon. FRRAAZZBBBB! The balloon zips away. The stored air escapes rapidly as it moves the balloon. The stored air is performing work. The balloon continues to move as long as there is pressure inside. When the pressure is gone, the balloon stops. Static electricity is like the air in the balloon. It’s stored energy, waiting to be unleashed.
But balloons aren’t perfect. They leak. In time, all balloons deflate. Why? Tiny holes in the balloon material let the gas escape very slowly. Static electricity also “escapes”. For instance, walk across a carpet and immediately touch a metal object. A spark will jump between your finger and the object. Walk across the carpet again but wait a while before touching anything. When you finally do touch the object, nothing happens. No spark The electricity you accumulated gradually dissipated, just like the air that escaped very slowly from the balloon. Where did it go? Out into the air, just like the gas from the balloon.
Wind and Water
To be useful, electricity must be moving. Why? Simple! Consider air. Calm air doesn’t do any work. It just sits there. Conversely, a strong breeze can pump water, move sailboats or make kites fly. Unfortunately, we can’t control the wind. But we can control water. Best of all, water works well as an analogy to electricity. For example, water in a pond is “static”. It doesn’t move. It might be good for fishing or swimming, but not for performing work. Static electricity doesn’t do any work either. We must first find a way to make it move.
Water flowing in a stream or river is capable of doing work. Years ago, water turned water wheels at grain mills. The water wheels were connected to large stones that ground wheat into flour and corn into corn meal. The water was doing something useful. As the water flowed downstream, it was used for many labor-saving applications.
Large rivers can turn immense water wheels. Small streams can’t. Why? The difference in current flow. Current flow is measured in gallons per minute, cubic feet per minute, or something similar. No matter what the measurement unit, current is the amount of water flowing in the river or stream.
Now wait a minute! Water won’t move on its own. Something has to make it move. Something like gravity.
62 Home Power #44 • December 1994 / January 1995
Image | Electricity for Dummies, Part 1
|Waste Heat to Power - ORC - - Waste Heat to Power System - Go to website|
Search Engine Contact: email@example.com