‘ c’ represents the 3 rd significant digit, which is the third band color of resistor. ‘ b’ represents the 2 nd significant digit, which is the second band color of resistor. ‘ a’ represents the 1 st significant digit, which is the first band color of resistor.
#22k ohm resistor color code code
Just have a look to the resistor color code chart below and see the calculations, how the resistance value is calculated according to this chart.Ĭalculating resistance for a 5-band resistor To calculate the resistance of a resistor, you can select the appropriate color bands in the above resistor color code calculator. Therefore it can be calculated from Table 2.1.3 that a 1MΩ resistor having a +/-2% tolerance (red band 5) might be expected to change its value by 1000Ω when its temperature changes by 20☌.A resistor is identified by its pattern of color of bands. Such changes in resistance are normally very small and measured in parts per million, e.g. In general, carbon resistors have a negative temperature coefficient and so will reduce their resistance as they heat up, metal film resistors however may be found to have either a positive or a negative temperature coefficient, depending on the manufacturer‘s choice of metals, the aim being to produce a resistor whose temperature coefficient, and so any variation in value is as close to zero as possible. The six band code adds another column to accommodate the temperature coefficient, which defines the likely change in resistor value per ☌, between its value over specified temperature range. Table 2.1.3 Six Band Resistor Colour Code 6 Band Colour Code The tolerance band on a resistor indicates the spread of possible values of any particular resistor, for example a resistor marked as 47KΩ +/- 10% will have an actual value somewhere between 42.3KΩ and 51.7KΩ Also this resistor can easily be changed for a different value where different versions of a circuit may be built, using the same PCB. Actually there is a reason that 0Ω resistors are available the reason is that where a wire link may be needed on a printed circuit board, it is easier for automated component insertion machines to insert a 0Ω resistor that is the same size and shape as a resistor, rather than have to use another process to insert a wire link. Notice also that where bands 1, 2 and 3 are black, this would signify a 0Ω resistor, which seems ridiculous as this would virtually be a piece of wire. Gold (+/-5%) and silver (+/-10%) being the most common tolerances. The fourth band, separated by a space from the three value bands, (so that you know which end to start reading from), indicates the tolerance of the resistor.
4.7Ω (or 4R7) would be indicated by yellow, violet(47), gold (divided by 10) = 4.7Ω. Two special cases of the multiplier band (band 3) are used for very small values where gold indicates that the first two bands must be divided by 10, and silver means divide by 100, e.g. Table 2.1.1 Four Band Resistor Colour Code The multiplier band will most commonly be some colour between black (no zeros), indicating a value between10 Ω and a value less than 100Ω, and blue (6 zeros), indicating a value in the tens of millions, e.g. This last version is used in many circuit diagrams and suppliers catalogues (where print may need to be very small) to avoid 2.2K being read as 22K instead of 2K2 where the decimal point may not be obvious. red, red, red indicates 2200Ω, which is normally called 2.2KΩ or 2K2. The first two of these bands indicate two numbers and the third, often called the multiplier band indicates the number of zeros, e.g.
In the four band resistor colour code illustrated in Table 2.1.1, the first three bands (closest together) indicate the value in ohms. The tables on this page illustrate three common forms for four, five and six band resistors. The Colour Codes used on resistors in carbon, carbon film and metal film types are widely used and a ‘must learn’ for electronics engineers.
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