−
n35 = 0.35nF or 3n5 = 3.5nF or 35n = 35nF and so on.
Sometimes the markings will be like 100K which means, k = 1000pF. Then the value will be 100 × 1000pF = 100nF.
Though these number markings are being used now-a-days, an International colour coding scheme was developed long ago, to understand the values of capacitors. The colour coding indications are just as given below.
| Band colour | Digit A and B | Multiplier | Tolerance (t) > 10pf | Tolerance (t) < 10pf | Temperature coefficient |
| Black | 0 | × 1 | ±20% | ±2.0pF | |
| Brown | 1 | × 10 | ±1% | ±0.1pF | -33 × 10-6 |
| Red | 2 | × 100 | ±2% | ±0.25pF | -75 × 10-6 |
| Orange | 3 | × 1,000 | ±3% | -150 × 10-6 | |
| Yellow | 4 | × 10,000 | ±4% | -220 × 10-6 | |
| Green | 5 | × 100,000 | ±5% | ±0.5pF | -330 × 10-6 |
| Blue | 6 | × 1,000000 | -470 × 10-6 | ||
| Violet | 7 | -750 × 10-6 | |||
| Gray | 8 | × 0.01 | +80%, -20% | ||
| White | 9 | × 0.1 | ±10% | ±1.0pF | |
| Gold | × 0.1 | ±5% | |||
| Silver | × 0.01 | ±10% |
These indications were used to identify the value of capacitors.
In these five band capacitors, the first two bands represent digits, third one indicates multiplier, fourth for tolerance and the fifth represents voltage. Let us look at an example to understand the color coding process.
Example 1 − Determine the value of a capacitor with a color code yellow, violet, orange, white and red.
Solution − The value of yellow is 4, violet is 7, orange is 3 which represents multiplier. White is ±10 which is the tolerance value. Red represents the voltage. But to know the voltage rating, we have got another table, from which the particular band to which this capacitor belongs, has to be known.
Hence the value of the capacitor is 47nF, 10% 250v (voltage for V band)
The following table shows how voltage is determined depending upon the bands the capacitors belong to.
| Band colour | Voltage Rating (V) | ||||
| TYPE J | TYPE K | TYPE L | TYPE M | TYPE N | |
| Black | 4 | 100 | 10 | 10 | |
| Brown | 6 | 200 | 100 | 1.6 | |
| Red | 10 | 300 | 250 | 4 | 35 |
| Orange | 15 | 400 | 40 | ||
| Yellow | 20 | 500 | 400 | 6.3 | 6 |
| Green | 25 | 600 | 16 | 15 | |
| Blue | 35 | 700 | 630 | 20 | |
| Violet | 50 | 800 | |||
| Gray | 900 | 25 | 25 | ||
| White | 3 | 1000 | 2.5 | 3 | |
| Gold | 2000 | ||||
| Silver |
With the help of this table, the voltage rating for each band of capacitors is known according to the color given. The type of voltage ratings also indicates the type of capacitors. For example, TYPE J ones are Dipped Tantalum Capacitors, TYPE K ones are Mica Capacitors, TYPE L ones are Polystyrene Capacitors, TYPE M ones are Electrolytic Band 4 Capacitors and TYPE N ones are Electrolytic Band 3 Capacitors. These days, the colour coding has been replaced by simple printing of value of the capacitors as mentioned previously.
Comments are closed.