Flightplan


Published  "online"  by the Flightmasters Model Aircraft Club, Inc. of Fort Smith, Arkansas.     It's purpose is to inform the membership and to promote interest  in the safe building and flying of model aircraft both in the Fort Smith Area as well as elsewhere.
      Volume 42                Number 2                               AMA Charter # 742                 IMAA Chapter # 362                                      February 2009

2009 Membership Fees are Due!
$5.00 Late Fee assesed after February 1, 2009


You probably recognize the couple in this photo, because we havn't changed all that much.  It is the second photo (the first was of Ron "kissing the Bride") ever taken of "Mr. & Mrs. Ron Roberts" and was taken on February 2, 1959 at about 7:47 PM, immediately following their marriage.

50th Anniversary

Jo Anne and Ron would like to invite all members of the Flightmasters Model Airplane Club to the celebration of their "50th Wedding Anniversary" at an "Open House" to be held on Saturday, December 31, 2009 from 1:00 PM until 4:00 PM, at their home.

Their address is 2008 So. 70th Street (above St. Edwards Hospital) in Fort Smith.


(Gifts are not expected!)


This issue is primarily devoted to a discussion of batteries.   I have been asked several questions recently in reference to batteries, so I thought it might be timely to cover it here.  


How do NiCd Batteries Work?

by Ron Roberts

All NiCd batteries presently used for Radio Control, as well as any other type of battery, are made up of "Cells". Some batteries may contain only a single "cell", such as used in a "clip on" glow driver, or there may be any number of "cells" wired together, such as those used for a "Receiver Pack" or "Transmitter Pack", for other uses.

To be as simple as possible, a "cell" is comprised of a single "electro-chemical unit" with one anode and one cathode. The "Anode" and "Cathode" are, simply, the Positive terminal and Negative terminals of the cell where wires are attached. Since there is an inherent voltage produced by the chemical reaction that takes place within the cell, all "Batteries" are made up of a number of cells which are connected in series to obtain the higher voltage we desire.

Let's use an example so we can understand what I'm talking about: Here you see a photo of a typical Car battery - what used to be called a "storage battery". Typical Lead/Acid Storage Battery We all know that most "Car Batteries" produce 12 Volts. How is that 12 Volts derived? Well... Car batteries are generally made up of what is called "Lead/Acid" cells. The chemical reaction inside of a single "Lead/Acid" cell produces 2 volts. That is considered a "Norm". The size of the "Plates or Electrodes" within the cell determine the CAPACITY (amount of current it will supply) of the cell, but regardless of the size of the "plates", each "cell" will only produce 2 volts.   So to get 12 Volts from a "Lead/Acid" Battery, we must wire Six (6) "Cells" in series so that the individual cell voltage will add. You can see the filler caps on each of the six "cells" in the photo.

Individual Cell Battery

Newer, so called "Maintenance Free" batteries may not have the filler caps, but still must have the six "cells" if they are 12 volt batteries.   You can see them in this photo of a typical "maintenance free" battery after the top has been removed and the sides "melted down" to expose the "plates" inside the battery case.

So... back to our subject of NiCd batteries:

Just like the car battery above, NiCd's convert a chemical reaction into electrical energy.  In the Lead/Acid cells of car batteries, we added a solution of Sulphuric Acid to the cells as an "electrolyte" and used Lead and Zinc as the plates. In a NiCd we use Nickel Hydroxide as one terminal and Cadmium as the other terminal. The electrolyte is usually a "pasty" solution of potassium hydroxide." NiCd Cell Construction If you click on the photo, you can easily see the make-up of a NiCd "Cell" in this photo at the left.   The Positive (+) terminal is connected to the Nickle Hydroxide material (Pink in the photo) and the Negative (-) terminal is the Cadmium (Green in the photo) which is connected inside the cell to the outer case of the cell.   The electrolyte, the solution of potassium hydroxide, is impregnated into the "Separator" in the photo (the Yellowish Orange color in the photo).


Go to Page 2 | Back to Index Page