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Issue 11, July 2010- Page 1                                                                                                      Previous Issues     
  

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

Medical Fluid Detector

Wily was at his desk when he got a call from a California medical company.  They needed a simple fluid detector but could not figure out how to design it themselves.  Would Wily have time to help them? 

The company made several kinds of fluid delivery systems.  Most were used to infuse chemotherapy drugs to a patient.  Instead of the usual IV drip method, where the fluid is held in bags, their system drew fluid from half liter to full liter plastic containers. 

As illustrated below, they used a metal syringe type needle, to draw the fluid from the container, through the open container lip....

con't page 7

Wily Widget,
the Lone Inventor
 with Gadget & Gizmo


WHAT THE WORLD NEEDS NOW
is a....External USB linked HD UPS
Many people like to connect an external hard drive to their laptop computer.  These devices are handy to backup the laptopís own hard drive.  Since 2TB drives are now common, a lot of information can be stored.  Usually, the hard drive is connected to the portable computer through a USB port and comes with its own 12v DC wall adapter power supply.  The peak power drawn from the supply can sometimes push 25 watts, so it is much more power than the laptop could ever supply through a USB port. So, if AC power is lost, information flowing to and from the external hard drive will not be possible.....
story con't on page 6

Dave's Pet Peeves
By: Dave Johnson  
                      
After some 40+ years in the electronics industry I have seen a lot of things. But, there are a few things that bug me when it comes to some circuits.  Below are some of my peeves.  I would love to hear about what things make your list.

  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.                               
Earth Signals
By: David Johnson
                                                                                                            
I have often wondered if any interesting electrical signals could be observed with copper probes driven into the ground.  As illustrated below. Three copper rods would be driven into the ground. The separation might be about 10 feet between rods.  The center rod is used as the reference for the other two....

   story con't on page 4

Cracked Solder Joints     
While out shopping the other day, I noticed a fairly new LED type traffic light, where several of the green LEDS were not working.  I think I know the reason for this.  Over the last several years, traffic lights have been shifting from classic incandescent lamps to LEDs.  The objective was to make the light assembly weigh less....

 story con't on page 3

Bad Rubber Mulch
A few years ago, my wife decided to try a new mulch product she saw at Home Depot.  This stuff is made from recycled car tires.  I have seen granules of old rubber tires being used for playgrounds and running tracks but this was the first time I saw it for use in gardens. The product was made of pure rubber....


story con't on page 5    

Lifted Weight Energy Storage
 

Some time ago I was reading about all the various ways that off-grid power system owners have tried to store their excess energy.  In a typical off-grid system, a mixture of energy producing devices might all be used at the same time. These may include photovoltaic solar panels and water heating panels mounted on a roof and a few wind generators here and there....

story con't on page 2 


July 2010     Issue 11

Page 1 Back
Envelope
Circuit
Diagnosis
Experimenter's
Corner
Good Idea
gone Badly
New Products Rants &
Raves
What the World
needs Now
Wily Widget


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