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Issue 3, November 2009 - Page 1                                                                                                      Previous Issues     
  

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

Vertically Lifting Security Gate Power Source

Wily got a call from one of his old clients.  A few years earlier Wily had designed a control circuit for the client’s nifty security gate, which lifted vertically, instead of the usual horizontal motion.  The act of moving the gate vertically and folding up was ideal for mountain homes, where narrow roads and heavy snow depths were common.  His old client had received a request from one of his customers who wanted a gate power source with a much longer life than the usual 3 to 5 years that a lead acid battery offered. The customer said that he had batteries die at some very inconvenient times.  Could Wily come up with something?

The vertical lifting security gates, as shown below, were most often installed far from any AC power source.  The standard system used a small 5 watt solar panel and a 12v sealed lead acid battery as a power source.  Both the battery and the control circuit board were housed inside an insulated plastic case.....con't page 7

 
WHAT THE WORLD NEEDS NOW is ... Drinking Water from Thin Air

A while back, I saw a demonstration of device which could pull enough water from thin air to keep an insulated tank full of a few gallons of clean pure cool water.  The unit was plugged into an AC wall outlet but did not need any plumbing.  I think this is a wonderful idea.  It sure beats man handling bottled water jugs......story con't on page 6

Hot Rock Geothermal Energy
By: Dave Johnson  
                     

I’ve been doing a lot of reading about various schemes to reduce America’s dependency on foreign oil.  I like the idea of a diverse approach where energy is produced using a wide variety of different methods.  Roof mounted photovoltaic solar panels, large and small wind generators, flex fuel vehicles and hybrid cars can all help.  Cellulose ethanol, biodiesel, compressed natural gas and even fuel from algae are some of the latest alternatives to petroleum based fuels.  But, it seems that many of the discussions on energy overlook one energy source which is just below our feet, at least here in the western half of United States where I live.  I think hot rock geothermal energy is one energy source which has a lot of potential.....  story con't on page 8

New Products 2008
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 I’m 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.                               

NiMH Battery State of Charge Monitor
By: Dave Johnson

Problem:   For the last 6 years or so, I have been using rechargeable NiMH batteries for my MP3 players, my portable CD players, batteries for my digital cameras and AM/FM radios.  Rechargeable batteries make sense for devices which are used frequently.  A good battery can be recharged 100s of times.  The ability to recharge a battery over and over can really save a lot of money, not to mention less material sent to the dump.  But, lately I have been quite frustrated and angry at some of the rechargeable NiMH cells I have purchased.....story con't on page 4

Connector Woes             

It was in the early 1970s. I was fresh out of college and found myself working for a major aerospace company in their power systems group.  Our group handled most of the power supplies and power converters for company’s space craft and missiles.  For many months I had been assigned the task of supporting the company with their various “squib fire circuits.”.... story con't on page 3

Bad Alarm Clock

My wife bought a simple clock to put near her bathroom sink.  She just wanted an easy to read clock that would display the time, day and date.  She saw the clock below in a typical blaster pack and thought it was perfect for her needs.  She got it home, installed the two batteries and immediately noticed something funny.  The display numbers did not display correctly.....story con't on page 5    

Supercapacitor Home Energy Storage Unit

Most off-grid home power systems use a large bank of lead-acid batteries to store excess power produced during daylight hours for later use at night. Some of these battery banks are massive, able to power the home’s electrical loads for many days.  Can existing supercapacitor technology be useful for storing electrical energy for a home?  Let’s explore this and see if it is technically feasible....story con't on page 2 

November 2009     Issue 3

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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