Phần hướng dẫn bên dưới chưa có bằng tiếng Việt nên được hiển thị bằng tiếng Anh. Bản thân máy tính đã được dịch đầy đủ.
Cách sử dụng máy tính này
- Choose the number of bands on the resistor.
- Read the bands from the end opposite the gold or silver tolerance band (the tolerance band is usually set slightly apart).
- Select each band's color.
Công thức
The first two (4-band) or three (5- and 6-band) bands are digits, the next is a power-of-ten multiplier, then tolerance, and on 6-band resistors a temperature coefficient.
R = (digits) × multiplier
Black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9
Tolerance: brown ±1%, red ±2%, gold ±5%, silver ±10%
Example
- Yellow, violet, red, gold.
- Digits 4 and 7, multiplier ×100 → 4,700 Ω = 4.7 kΩ.
- Gold = ±5%, so 4.465–4.935 kΩ.
Câu hỏi thường gặp
Which end do I start reading from?
Start from the band closest to a lead, away from the gold or silver band. If unsure, the reading that gives a standard E-series value (like 4.7 kΩ) is usually correct.
What if there are only three bands?
A 3-band resistor is a 4-band code without a tolerance band: two digits and a multiplier, with ±20% tolerance.
What does the temperature coefficient mean?
How much the resistance changes per degree Celsius, in parts per million. 100 ppm/K means 0.01% per °C.