แบบฝึกทักษะการอ่านค่าแถบสีตัวต้านทานอย่าง่าย #ครูสมมุ่ง อินนุรักษ์ #ครูมุ่ง

Introduction

This tutorial provides a straightforward guide to reading resistor color codes, specifically focusing on 4-band resistors. Understanding how to interpret these color bands is essential for electronics enthusiasts and professionals alike, as it helps in identifying resistor values quickly and accurately.

Step 1: Understanding Resistor Color Bands

• Resistors typically have color bands that indicate their resistance value and tolerance.
• A 4-band resistor includes:
  • Two significant figure bands
  • One multiplier band
  • One tolerance band

Color Code Table

• Familiarize yourself with the color code for each digit:
  • Black (0)
  • Brown (1)
  • Red (2)
  • Orange (3)
  • Yellow (4)
  • Green (5)
  • Blue (6)
  • Violet (7)
  • Gray (8)
  • White (9)

Tolerance Colors

• Gold (±5%)
• Silver (±10%)
• No color (±20%)

Step 2: Reading the Resistor Value

1. Identify the Color Bands:

   • Look at the resistor and note the colors of the first two bands.

2. Convert Colors to Numbers:

   • Use the color code table to convert the first two colors to their corresponding digits.

3. Determine the Multiplier:

   • Identify the third band’s color and convert it to the multiplier value (e.g., red = x100).

4. Calculate the Resistance:

   • Combine the first two digits and multiply by the value from the third band.
   • Example: If the bands are red (2), blue (6), and yellow (x10^4), the calculation would be:
     • Resistance = (26) x (10^4) = 260,000 ohms or 260kΩ.

Step 3: Understanding Tolerance

• The fourth band indicates the tolerance level of the resistor value.
• This will give you a range of acceptable values for the resistor.
  • Example: If the calculated resistance is 260kΩ and the tolerance is ±5%, the actual resistance can range from 247kΩ to 273kΩ.

Step 4: Practical Applications

• Use this knowledge in circuit design and troubleshooting.
• Always double-check resistor values with a multimeter to ensure accuracy.

Conclusion

By following these steps, you can effectively read and interpret the values of 4-band resistors. Knowing how to accurately determine resistor values will enhance your skills in electronics and circuit assembly. As a next step, practice with actual resistors and test your readings against a multimeter to reinforce your learning.