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Issue 1-2011,  January                                                                                              Previous Issues     

Let's drop in on Wily and look over his shoulder at his latest project....

Underground Gate Opener

Wily was watching the snow come down when he got a call from a mining company.  They needed his help.  They had a section of a deep underground salt mine that was blocked by two swing type security gates. Vehicle access to the area was tightly controlled.  The area did not have any AC power available for the gates.  The mining company had been using a standard driveway swing gate, controlled by a keypad, powered by a 12v motor and a 12v seal lead acid battery. However, the batteries had to be replaced periodically and taken up to the surface to be recharged.  Could Wily come up with something, so they would not have to swap out the batteries?

The two gates were at opposite ends of a looping branch tunnel, off the main mine room. The area was used to house special equipment and materials and was not used very often.....

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Wily Widget,
the Lone Inventor
 with Gadget & Gizmo

is a....Miniature AC to DC Power Supply
Electronic systems are getting quite efficient these days.  I seldom design a small product that requires more than 100 milliwatts of power.  Often, if the product is not going to be powered by batteries, it requires a wall mounted AC to DC power adapter or a small on-board power module.....
story con't on page 6
Optical Fiber Pressure & Motion Test Circuit
By: Dave Johnson
Optical fibers have been used for detecting motion and pressure for quite a few decades now.  If you would like to experiment with this interesting technique, you can use the circuit below....

   story con't on page 4

Reversed Battery Polarity   

I received a call from a toy company.  They were puzzled by some field failures they had been having.  The company manager said his engineers assured him that the failures were not due to a design flaw but due to bad parts, a manufacturing problem or customer abuse.  But, the manager was not so sure.  He wanted a second opinion.   

He sent me a few good units, a documentation package and some defective units, which had been returned by some customers.....

 story con't on page 3

Bad AC to DC Wall Power Adapters
I see a troubling trend developing.  AC to DC power adapters for various electronic devices are failing at an alarming rate.  Iíve had two die lately within a week of each other.  Both were just a few months old.  I hear through the technical ďgrapevineĒ that Iím not the only one who has experienced such failures.....

story con't on page 5    

Solar Energy Myth Busting I

Iím sure you have heard this myth.  ďThe average home roof receives enough solar energy each day to provide all the electrical, heat and air-conditioning needs inside the home.Ē  I always thought that such a statement was factual.  But is it really true?  Letís do some quick math and find out.....

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January 2011

Page 1 Back
Good Idea
done Badly
What the World
needs Now
Wily Widget

Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches

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