HOME Schematics Hobby Corner Dave's Circuits Electronic Resources Book Corner Contact Info

Issue 9, May 2010- Page 1                                                                                                      Previous Issues     

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

Earth Battery

It seems that Wily gets these kind of calls every month or so.  This call came from an inventor who thought he had the solution to all of the energy problems of the world.  As the drawing below illustrates, the inventor pounds two metal rods into the ground.  One is made of copper; the second is made of aluminum.  When he measures the voltage across the two rods, he sees about one volt on his voltmeter.  His plan was to wire up 100s of these rods together to produce enough voltage to power his house. I asked him if he had measured the current this battery of his could produce.  Well, no, he h ADNít.  Wily strongly suggested he make that measurement.  Wily also suggested that he use the simple volts times Amps equation to predict just how much power such electrodes in the ground could produce.  Wily told the caller to call back if the current was more than a few tens of milliamps.  The caller never did call back....
con't page 7

Wily Widget,
the Lone Inventor
 with Gadget & Gizmo

WHAT THE WORLD NEEDS NOW is a....Large Outdoor Thermometer
I got an email from a guy in Death Valley California.  He worked at a general store where the outside temperature often exceeds 120 degrees F.  He wanted a large analog thermometer display with some advertising nearby, so patrons could snap photos in front of the display, showing these hellish temperatures.....
story con't on page 6

Stiff Wires from China
By: Dave Johnson   
Iím seeing another disturbing trend coming out of China.  I see more and more devices with cords and wires attached which are brand new yet the wires or cords are very inflexible.  About once each year the wife and I have to buy a new electric blanket.  Iíll save that story for another rant about the terrible quality of those devices.  Anyway, the last blanket we bought came with the usual set of dual heat I setting controls for....

  story con't on page 8

New Products 2009
New product announcements are made nearly every day.  I subscribe to many trade journals and each is filled with hundreds of flashy advertisements.  But, only a few of those product ads catch my eye.  Since Iím a circuit designer, I especially like those components that trigger many new application ideas in my mind.  Sometimes it is the smallest products that are the most useful.  I often discovered new products in surplus electronic catalogs.  The surplus companies often buy up stock that came from companies that went out of business.  Bad marketing or bad management may have killed a perfectly good product idea.  Their loss can be your gain if you can spot the bargain.                               
X100 Scope Probe
By: David Johnson
These days, I seem to be designing a lot of circuits, which run on very low power.  Often the resistors being used in these circuits are in the multiple megaohm order of magnitude.  When looking at signals across such resistors, even the 10M load a typical X10 oscilloscope probe will produce large measurement errors and will influence the circuit operation.

   story con't on page 4

Infrared Remote Battery Voltage Droop
By: Dave Johnson    

A while back I bought a new small flat screen TV for my bedroom.  My wife wanted one so she could watch and listen to the TV while in bed, before rolling over to sleep.  After a few months of use, she noticed that the TV would often not respond to the infrared remote.  I too noticed that you had to point the remote directly at the TV to get it to change a channel.  When new, the remote would be able to do the same channel change while pointing at the ceiling.  I took the remote down to the basement lab and cracked it open. 

 story con't on page 3

Bad Throw Rug

A while back my wife and I bought an area rug from Lowe's.  I think we paid a couple hundred bucks for the thing.  It was positioned in a heavy traffic area between our front door and the dinning room.  Within weeks after the rug was laid down, I noticed that one corner of the rug started to curl.  My wife tried to flatten the thing out by placing a sticky pad under that corner, to help hold the thing down.  However the curl progressed and got even worse.  It now looks as the photo below slows.  We have tried tying a cord on the corner and maintained a constant stretching force without any success.  The rug was made in India.  What ever happened to the good old US rug manufacturers?

story con't on page 5    

Hydrogen Energy Storage

In spite of all the research going on around the world, there is still no ideal way to store electrical energy.  Batteries are still the gold standard for most off-grid homes.  Off-grid power system owners are always looking for ways to capture and store energy since there is no AC power grid to do an energy exchange with.  Like a careful money manager, they have to try and make more energy than they need and put some aside for a rainy day.  Poor weather means pulling energy from the savings account. When their account (battery) in empty, they then have to fire up their gasoline or diesel generator and replenish the battery reserves.....

story con't on page 2 

May 2010     Issue 9

Page 1 Back
Good Idea
gone Badly
New Products Rants &
What the World
needs Now
Wily Widget

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

 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |   
Privacy Policy

Discovercircuits.com endeavors to credit original designers.   Please alert us by eMail so we can
delete links to material that have been copied without your permission
.   Thank you.

© Copyright of all original material on this website is the property
of David A. Johnson, P.E. (Dave Johnson & Associates ) unless otherwise noted.  

Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.
All material is provided "as is" without guarantees or warranty of any kind, either expressed or implied.