As one of the commonly used components in circuits, resistors play a vital role in various electronic devices. Understanding the main characteristics of a resistor is critical to the correct selection and application of the resistor.
1. Nominal resistance
The nominal resistance value of a resistor refers to the resistance value marked on it, which is an important reference when selecting a resistor.
2. Allowable error
The allowable error is the percentage of the difference between the actual resistance value and the nominal resistance value, which reflects the accuracy of the resistor. Different accuracy levels correspond to different allowable errors, such as ±0.5%, ±1%, ±2%, etc.
3. Rated power
The power rating of a resistor is the maximum power allowed to be dissipated under specific environmental conditions. Wirewound and non-wirewound resistors are available in different power rating series, covering the range from 1/20W to 500W.
4. Rated voltage
The rated voltage is the voltage calculated based on the resistance value and rated power, and is the maximum voltage that the resistor can withstand.
5. Maximum working voltage
The maximum operating voltage is the maximum continuous operating voltage allowed by the resistor, but special attention needs to be paid to its limitations in low pressure environments.
6. Temperature coefficient
The temperature coefficient reflects the effect of temperature changes on the resistance value. The smaller the temperature coefficient, the better the stability. It can be divided into positive temperature coefficient and negative temperature coefficient.
7. Aging coefficient
The aging coefficient is the relative change percentage of the resistance of a resistor under long-term load at rated power, which is directly related to the life of the resistor.
8. Voltage coefficient
The voltage coefficient represents the relative change in the resistor when the voltage changes by 1V within a specified voltage range.
9. Noise
The noise present in the resistor includes thermal noise and current noise, which has a certain impact on the stability of the circuit. Understanding these characteristics will help you select the correct resistor and optimize your circuit design.