Adrian Freed: Fueling imaginations

Overall good book but the author is mistaken on some of the theory 2010-07-16

Reviewer: J. Vanwechel

The author uses an outdated analogy of electricity using a water tank to represent the batteries, and its this analogy that probably causes him to get the definition wrong on some physical quantities. I don't think it will cause any problem if your are just interested in hobby use and not interested in theory, however if you want a more accurate understanding of theory I would suggest that you look at a physics text. Or at least look up the terms on wikipedia.

In case you're interested here are some of the errors I found, (but I really would recommend that you look it up in text or on wikipedia where the subject is explained more clearly and in more detail): on pg 36. He started by saying that electrical potential is measured in coulombs and is a measured by adding up charges, while it is true that coulombs are a measure of charge, electrical potential is NOT charge - the difference in electrical potential between to points is commonly referred to as voltage, and what is it measures is how much a charged particles electrical potential energy would change if moved from the first point to the second point (so 1 volt = 1 joule per coulomb). If you want to use a fluid analogy in a circuit the charge stays on the conductors so they are like pikes, so you would have to picture a closed fluid system. Voltage would be analogous to height, electrical force would be analogous to the force of gravity or weight. The battery would be analogous to a pump, that would lift the water to a certain height, and the water flowing down through pipes is analogous to the circuit. So just as when water drops in height it converts its gravitational potential energy into other forms of energy such as drag (resistance) to do work (like a light bulb or a motor) or to kinetic energy. The electrical analog to fluid flow rate is current (measure in units charge per units time, 1 ampere = 1 coulomb / second). A watt is NOT a measure of energy, a joule is a measure of energy (and a volt is 1 joule / coulomb) watt is a measure of power (think horsepower) and 1 watt = 1 joule / second. Work is a measure of a force through a distance and is measure in newton meters, but here is the key: work doesn't come out of nowhere, energy is used to produce work, so 1 newton meter = 1 joule ( if you want to derive them they are both kg times (meters squared) over seconds squared).
Another thing he says is that if you put to batteries in parallel it doubles the current but this is violation of Ohms law, if the batteries are in parallel the voltage is the same as if you had just one battery so by ohms law V=I/R if V is constant then R is constant (because real batteries have internal resistance, if that is the main source of resistance in your circuit, then yes the current would effectively double but in a typical circuit the batteries internal resistance can be ignored, and current would remain roughly constant) What generally happens if you hook up two batteries in parallel is they would last twice as long as if you had just one since each battery stores roughly the same amount of energy in the form of electrons stored in the chemistry so by using double the batteries you double the number of electrons available and by Ohm's law you use the electrons at the same rate (current aka amperage).
Ohms law also explains why if you have near zero resistance (even wires have some resistance) that your battery drains really quickly, the current goes up since there is little resistance to keep the electrons where they are, so basically the electrons leave the battery as quickly as the chemistry in the battery is capable of releasing them so the battery drains very quickly, its this huge number of electrons moving through the wire in a relatively short amount of time that cause all the heat.

BEST place to start 2010-06-24

Reviewer: Jeremiah Towe

I got this book thinking I knew the basics of electronics. Well, I didn't. This book takes you back to basics and builds your knowledge from that CORRECTLY. Amazing book!

Where was this book when I was in college or before even that?!!! 2010-06-03

Reviewer: Jack G. Atkinson Jr.

Here am I, over 30 with a Master's Degree in Electrical Engineering. I pick up this book because one day I would like to teach my son electronics, and before that teach some homeschool classes in my area on electronics. I was completely amazed at how well this book is laid out for teaching someone new to electronics! I remember my earlier days in junior high when my techie granddad gave me an electronic kit that sat on my shelf collecting dust, because the manual was just awful. I sure wish I had this book back then! I would have also have made a great introductory electronics class in college, instead of all that boring theory the professor droned on and on about all day then go to lab and stare at the breadboard. I made straight A's in those early classes, but not very confidently and no thanks to the professor.

The books does a wonderful job of building upon concepts and moving onto the next without jumping too far out ahead. It has some nice historical asides in the sidebars about inventors and scientists for a special touch. The downside is getting all the parts for the experiments, so I recommend you cough up the dough to get the Maker's kits that go with the lessons if you don't want to spend a lot of time ordering and searching. However, ordering and searching for those parts is another education in itself, because one must eventually learn to acquire these items if they want to do more electronics work in the future.

Overall, this book is worth the money!

Excellent getting started in electronics book 2010-05-06

Reviewer: Brooke T. Hedrick

This book is great for getting started in electronics. It starts off basic, but digs in and gets interesting very quickly. It includes excellent color illustrations and an easy to read copy.

Great book for beginers 2010-04-14

Reviewer: Imran Sharafat

I got this book for my ten year old son who has been tinkering with electronics for the past few years. This book is very well written for people with very little or no background in electronics theory. Author uses pictures and cartoon to make the subject interesting. For each lesson and concept there is an experiment. I have a large library of books on electronics but over all this is best book I have found to teach some one basic electricity and electronics.