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

Issue 8, April 2010- Page 1                                                                                                      Previous Issues     

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

Corona Monitor

Wily was just about to have some lunch when his phone rang.  It was from a local medical equipment company.  They made kidney dialysis machines.  They also made lots of the non-reusable blood filters, which were used on their machines.  The filters were rather complex canisters of plastic sheets, all glued together.  To enhance the glue adhesion, the company ran the plastic sheets through a special machine, which bombarded the material with a high voltage 40KV 20KHz discharge.  This “corona discharge” broke up the plastic bonds on the surface, allowing the glue to stick.  

The company had been using their corona machine for several years without too many problems. ....

con't page 7

Wily Widget,
the Lone Inventor
 with Gadget & Gizmo

WHAT THE WORLD NEEDS NOW is a....Candle Flame Powered Battery Charger
Thermoelectric devices have been around for a long time.  By running electrical current through them, one side gets hot while the other gets cold.  Many are used to cool sodas in a cooler, keep a computer’s processor cool and have even been used on spacecraft.  When run backwards, by applying heat to them, they can also produce electricity. I would sure love to see a well designed thermoelectric generator, which could produce some electricity from the heat of a candle flame. I would only expect a watt or two of power at most from this system,....
story con't on page 6

Strange Science
By: Dave Johnson  
Strange Heat Production:  About 30 years ago I was part owner of a research and development company.  We were trying to develop a number of inventions as well as provide consulting engineering services.  We had a PhD physicist helping us with some of the more sticky technical issues.  One day the physicist showed me a copy of an engineering report he had obtained from a well-known engineering company in the Denver area.  The company asked us to review and comment on the report.  The report described a strange heat phenomenon, which had stumped some of their top engineers....

  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 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.                               
Charging Alkaline Batteries
By: Dave Johnson
A standard flashlight, which uses an incandescent lamp and alkaline batteries, will usually become useless when the battery voltage drops below a certain point.  We have all experienced switching on a flashlight only to be greeted by a weak yellow glow from the bulb instead of bright white light....

   story con't on page 4

PCB Fabrication Problems               
I got a frantic call from one of my old clients.  About three years earlier I had designed a detergent soap mixing control circuit for them.  The circuit monitored the alkalinity of a soap and water mixture and by controlling the water flowing into the mixing tank; the circuit could maintain a fixed soap concentration.  They sold a few thousand mixing systems per year.  They typically bought about 500 printed circuit boards at a time and soldered the surface mounted components onto....

 story con't on page 3

Bad Fluorescent Night Light

The wife knows that I’m constantly searching for that perfect night light design.  When she saw these in a twin blister pack, she knew they had my name on them.  I really liked the style and size.  The package said that they consumed only 1.6 watts, which was only 40% of the typical 4 watt incandescent night light style lamp.  Being fluorescent, they should also produce more light and last longer than the typical 6 months I usually got from the standard incandescent 4 watt lamps. 

story con't on page 5    

Please check back, still editing

Insert paragraph 1 of text here   

story con't on page 2 

April 2010     Issue 8

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.