<!-- .at_3{FONT-SIZE: 10.5pt; FONT-FAMILY: Arial; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA} .at_1{FONT-FAMILY: 宋体; mso-bidi-font-size: 10.5pt; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial; mso-bidi-font-family: Arial} .at_5{mso-special-character: line-break} .at_2{FONT-FAMILY: Arial; mso-bidi-font-size: 10.5pt} .at_4{FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-ascii-font-family: Arial; mso-hansi-font-family: Arial; mso-bidi-font-family: Arial; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA} .at_0{MARGIN: 0cm 0cm 0pt} -->  功率型MF72NTC热敏电阻器的选用原则1.电阻器的最大工作电流〉实际电源回路的工作电流2.功率型电阻器的标称电阻值R≥1.414*E/Im式中E为线路电压Im为浪涌电流对于转换电源，逆变电源，开关电源，UPS电源，Im=100倍工作电流对于灯丝，加热器等回路Im=30倍工作电流3.B值越大，残余电阻越小，工作时温升越小4.一般说，时间常数与耗散系数的乘积越大，则表示电阻器的热容量越大，电阻器抑制浪涌电流的能力也越强。MF72功率型NTC热敏电阻器