A color code resistor is a type of resistor that uses colored bands to indicate its resistance value and tolerance. The four band color code is the most common variation, making it easy to identify the resistor's properties visually.
Understanding the Color Bands
These resistors typically have multiple colored bands painted on their body, each representing a specific value. Here's a breakdown of what each band usually indicates:
- First Two Bands: These bands represent the significant digits of the resistance value.
- Third Band (Multiplier): This band indicates the power of ten by which the significant digits should be multiplied.
- Fourth Band (Tolerance): This band shows the percentage of variation from the stated resistance value that is acceptable.
Decoding the Color Bands
To determine the exact resistance value, you need a color code chart, a quick reference to determine the meaning of each color.
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | 1 | - |
| Brown | 1 | 10 | ±1% |
| Red | 2 | 100 | ±2% |
| Orange | 3 | 1,000 | - |
| Yellow | 4 | 10,000 | - |
| Green | 5 | 100,000 | ±0.5% |
| Blue | 6 | 1,000,000 | ±0.25% |
| Violet | 7 | 10,000,000 | ±0.1% |
| Grey | 8 | - | - |
| White | 9 | - | - |
| Gold | - | 0.1 | ±5% |
| Silver | - | 0.01 | ±10% |
| None | - | - | ±20% |
Example
According to the reference, consider a resistor with color bands of green, blue, red, and gold:
- Green: Represents the digit 5.
- Blue: Represents the digit 6.
- Red: Represents a multiplier of 100.
- Gold: Represents a tolerance of ±5%.
Therefore, the resistor's value is calculated as 56 x 100, which equals 5,600 ohms, with a tolerance of ±5%.
Why Use Color Codes?
Color codes make it easy to identify resistor values, particularly on small components where it’s not feasible to print numerical values directly. This method is universal, allowing technicians and engineers to quickly and accurately determine the resistance of a component.
Practical Insights
- Memorization Aid: Using mnemonic devices helps remember the color sequence. For instance, "Bad Boys Ravish Our Young Girls But Violet Gives Willingly" can help remember the colors in order.
- Reading Direction: Always read the bands from the end closest to one of the leads, usually towards the tolerance band which is often slightly separated.
- Five-Band Resistors: Some resistors use a five-band code, with the first three bands denoting the significant figures and the last two being the multiplier and tolerance respectively.
Conclusion
Color code resistors are a standard way of marking the resistance value of resistors, enabling easy identification using the universally understood color chart. The four-band system is the most common.
