BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 1
Use the example colors shown in figure 10. Since red is the color of the
first band, the first significant digit is 2.
The second band is blue;
therefore, the second significant digit is 6.
The third band is orange,
which indicates that the number formed as a result of reading the first two
bands is multiplied by 1000. In this case 26 x 1000 = 26,000 Ohms. The
last band on the resistor indicates the tolerance; that is, the
manufacturer's allowable deviation from the numerical value given on the
resistor.
In this instance its color is silver, and the tolerance is 10
percent plus or minus the value of the resistor.
The allowed limit of
variation in ohmic value of this particular resistor is 23,400 to 28,600
Ohms.
When measuring resistors you will find situations in which the quantities to
be measured may be extremely large, and the resulting number using the basic
unit, the Ohm, may prove too cumbersome. Therefore, a metric system prefix
is usually attached to the basic unit of measurement to provide a more
manageable unit. Two of the most commonly used prefixes are kilo and mega.
Kilo is the prefix used to represent thousand and is abbreviated k. Mega is
the prefix used to represent million and is abbreviated M.
Simplifying the Color Code. Resistors are the most common components used
in electronics.
The technician must identify, select, check, remove, and
replace resistors. Resistors and resistor circuits are usually the easiest
branch of electronics to understand.
The resistor color code sometimes presents problems to a technician.
It
really should not, because once the resistor color code is learned, he
should remember it for the rest of his life.
Black, brown, red, orange, yellow, green, blue, violet, gray, and white is
the order of colors the technician should know automatically.
There is a
memory aid that will help in remembering the code in its proper order. Each
word starts with the first letter of the colors.
Bad Boys Run Over Yellow Gardenias Behind Victory Garden Walls.
22