Ceramic Resistor Power Rating

Chip resistor de rating calculator dbm linear power converter hybrid coupler designer lc resonance calculator lc balun designer lc matching network designer microstrip impedance calculator mixer spur calculator mmwave link budget calculator noise figure temp converter optimal mitre calculator path loss calculator phase noise to jitter converter.

Ceramic resistor power rating.

At temperatures above 70 c the resistor is derated using the electrical stress ratio. Most manufacturers specify the power rating at 70 c and free airflow conditions. Wirewound common in power supplies and other equipment where lots of power is dissipated a wirewound resistor is made just as you might expect. Thus if a resistor has a power rating of 1 4 watts 1 4 watts is the maximum amount of power that should be fed into the resistor.

Thus the power dissipated by the resistor will be just 0 09 w well under the maximum that can be handled by a 1 4 w 0 25 w resistor. The ceramic coating combines a high insulation and physical protection with good heat dissipation. They have power dissipation ratings much lower than those of grid resistors or water resistors and can usually dissipate no more than a few watts provided they have appropriate cooling. The ceramic resistors offer the advantages of carbon composition resistors pure resistance stability reliability and pulse stability in power electronic applications though these too have poor tolerance levels typically 10.

Typical power ratings are between 4 and 17 watts. The power rating of a resistor is the specification given with a resistor that serves to tell the maximum amount of power that the resistor can withstand. The film is deposited on a ceramic sheet. The thickness and length of film determines the resistance.

P i v. Design engineers dealing with surge events need to understand the significant difference between pulse voltage withstanding and pulse power withstanding resistors. Once you know the voltage and the current you can calculate the power that will be dissipated by the resistor by using the power formula. Stress ratio operating power rated power.

The recommended value is 80 for fixed resistors and 75 for variable resistors. One of the most significant market drivers in the resistor industry currently is the need for pulse withstanding resistors. The maximum surface temperature is around 300 c and the tcr varies from 250 till 400 ppm c. The resistor itself consists of a metal oxide film deposited onto a ceramic substrate.

Because of their extremely small size surface mount resistors have very low power ratings from 1 10 to 1 4 watt.