joesacher.com

I’m sorry, you can no longer win $15,000 by reading this book. It was the announcement of the solution to the 10 cipher challenges, located in the back of The Code Book, that made me aware of this book. Money aside, if you are interested in learning of the history of codes and ciphers, this book is for you! Did you know that Mary Queens of Scots was killed by Queen Elizabeth, because her code was not strong enough to foil the code breakers of the time. Have you ever heard of the Navajo Code Talkers that offered the US Marines a method of secure ground communications in World War II? (Probably more so after the Windtalkers movie.) Do you know the full story behind the breaking of the German’s Enigma Code in the same war? Do you know that the first computer was build in England, not the US?

I knew most of the above facts before reading this book. However, as with most people’s understanding of history, my ideas were seriously flawed in the details. This book allows you to start out with the world’s earliest codes and learn how to do a little code breaking of your own. If you are at all interested in either the technical or historical history of code breaking, you will enjoy this book. This is the first technical history book that read like a good piece of fiction. When you realize that the action packed stories are historical fact, the book only shines more.

The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography ISBN: 0385495323 at Amazon

This is a picture of a capacitor from a Chinese company, after being cut open. Inside, it is just a small capacitor. There are two problems with this. First, capacitors are rated with two values: Working Voltage and Capacitance.  The most important is the working voltage. On the large cap, it is listed as 50V. Notice the smaller cap is 35V. When a capacitor is submitted to over voltage for a long period of time, the dielectrics (the insulator between the two sides of the capacitor) in the capacitor break down and it explodes. Yee-haw. The capacity issue is a little less troubling. You bought 6800uF, but were only given 2200uF. You got a capacitor that is 1/3 of what you thought it was. These are most commonly used in power supply filters and the device it is used in will be subject to the power line frequency hum, do to poor filtering. The business model on the company is genius. By capacitors, put them in a pretty case, sell for more money. A quick search shown retail cost of the small capacitor at about $1.50. The large one, near $3.00. Genius. Until power supply capacitors start exploding.