ELECTRONIC PRINCIPLES - OD1647 - LESSON 1/TASK 1
capacitor, hold the capacitor so that the three arrows point to
the right (>). The first dot at the base of the arrow sequence
(the leftmost dot) represents the capacitor TYPE. This dot is
either black, white, silver, or the same color as the capacitor
body. Mica is represented by a black or white dot, and paper by
a silver dot or a dot having the same color as the body of the
capacitor. The two dots to the immediate right of the type dot
indicate the first and second digits of the capacitance value.
The dot at the bottom right represents the multiplier to be
used. The multiplier represents picofarads. The dot in the
bottom center indicates the tolerance value of the capacitor.
Let's assume that, we have a capacitor in our hand. To read
this capacitor, first, turn the capacitor so that the arrows (>)
are pointing from left to right. Read the first dot, which in
this case is white. Looking at the chart in figure 47, on the
previous page, we see that white indicates a mica capacitor.
Now read the first digit dot (or second dot) the second dot is
brown. Referring to the chart in figure 47, we see that brown
indicates 1. Then read the second digit dot, which in this case
is red. Looking at the chart, we see that red indicates a value
of 2. This gives us, thus far, 12. Now read the multiplier
dot, which is at the bottom righthand side of the capacitor.
Remember that the multiplier is in picofarads. In this case,
the multiplier dot is also red. Looking at the chart., we see
that red indicates a multiplier of 100. Now multiply the
multiplier by the first two digits (100 x 12 = 1200 picofarads).
Finally, read the last dot, which is the tolerance dot. In our
(example, the tolerance dot is blue. Looking at the chart, we
see that blue indicates a tolerance of + 2%.
According to the above coding, the capacitor is a mica capacitor
whose capacitance is 1200 picofarads with a tolerance of 2%.
The capacitor shown in figure 48, on the following page, is a
tubular capacitor. Because this type of capacitor always has a
paper dielectric, the type of code is omitted. To read the
code, hold the capacitor so that the band closest to the end is
on the left side then read left to right. The last two bands
(the fifth and sixth bands from the left) represent the voltage
rating of the capacitor.