Molded Mica Capacitor Color Code
Number of zeros
after second figure
Three Dot Color Code
The color dots must be read in the correct sequence (A, B, C) from left to
right in order to correctly interpert the color code. In order to make
certain that the capacitor will be held in the proper position while the dots
are being read, manufacturers have adopted several 3-dot marking
arrangements. In that shown in illustration No. 1 above, the capacitor must
be held so that the manufacturer's name or trademark appears right side up,
as shown. Then the dot will be read in the proper sequence if they are read
from left to right. Another somewhat similar arrangement is shown in
illustration No. 2 above. Here, the three colored dots are stamped on an
arrow molded in the capacitor case. The arrow always points to the correct
direction of reading.
On some makes of capacitors, the dots are shaped so they are slightly
'pointed' in the direction in which they are to be read, others
have an adjacent direction-arrow molded alongside each dot as shown in
illustration No. 3.
3-Dot Example: Red(A) Green(B) Black(C) = 25 mmfd. = .000025 mfd
Extra Markings for Voltage Rating & Capacity Tolerance (5-Dot
On types where two extra color dots appear (making 5 in all, see illustration
No. 4), whether on the face or on the reverse side of the molded case, the
color of the fourth dot (D) indicates the d-c voltage rating, in accordance
with the tabulation of the (D) column above. No color in this position
implies a voltage rating of 500 volts d-c.
The color of the fifth dot (E) indicated the percent tolerance on the
accuracy of the capacity rating. No color in this position indicates a
tolerance of +/- 20% in the capacity value. A capacitor with the 5-dot
color code in shown in illustration No.4 above.
Six Dot Color Code
When there are three significant figures in the capacity value, and the
voltage rating and tolerance information is also to be indicated, a 6-dot
color code is usually employed
On capacitors marked with six dots (see illustration No. 5 above) the upper
three (A, B, B1) indicate the capacity and the lower right hand dot (C)
indicates the number of zeros to be added. The remaining two dots (D) and
(E) indicate the d-c working voltage rating and the capacity tolerance
respectively, as shown in the illustration.
6-Dot Example: Brown(A) Red(B) Green(B1)
Orange(D) Green(E) Brown(C)
= 1250 mmfd., 300 d-c working voltage, +/- 5% tolerance
Micro-Micro Farad To Micro-Farad Conversion
|1,000||.001|| || || |
Note: A micro-microfarad is one-millionth (1/1,000,000) of a microfarad.
To convert mmfd. to mfd., move the decimal point six places to the left. (For
example, 3500 mmfd. is equivalent to .0035 mfd.). To convert mfd. to mmfd.,
move the decimal point six places to the right. (For example, .00025 mfd. is
equivalent to 250 mmfd.) See table above.