Bot’n Roll ONE A User Assembling Manual
4.2.2. RESISTORS
Electrical resistance is the name given to an element
that opposes the passage of electric current (direct or
alternatng).
Usually resistance is represented by the letter R and
its unit of measurement by the Ohm (Ω).
The nominal value is represented by coloured bands (colour code), which satsfes the following criteria:
exponent of the power of 10 that multplies the original number, and fnally the fourth colour (slightly
shifed to the right) corresponds to the tolerance in percentage.
Colour
1
st
Band
2
nd
Band
3
rd
Band
4
th
Band
1
st
Figure
2
nd
Figure
Multplier
Tolerance %
Silver
0.01
+//- 10
Gold
0.1
+//- 5
Black
0
0
X 1
No colour
+//- 20
Brown
1
1
X 10
Silver
+//- 1
Red
2
2
X 100
Gold
+//- 2
Orange 3
3
X 1,000
+//- 3
Yellow
4
4
X 10,000
+//- 4
Green
5
5
X 100,000
Blue
6
6
X 1,000,000
Violet
7
7
Gray
8
8
X 0.1
White
9
9
X 0.01
Table 1: Resistance colour codes
Example
: What is the value of the resistor on the picture?
The frst two colours: yellow (4) and violet (7) form the number 47.
The third colour, orange (3), corresponds to the exponent of the
power of ten: 10
3
, or multply by 1000, the fourth colour, silver (10%),
indicates the tolerance. Thus, the electrical resistance is:
R = 47000Ω with 10% tolerance or R = (47 000 Ω ± 4700Ω)
©Copyright 2018, SAR - Soluções de Automação e Robótca, Lda.
17
Fig. 17: Resistance – lines with colour codes
Fig. 18: Resistor example
Summary of Contents for ONE A
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