NTC功率型热敏电阻.pdf

NTC THERMISTORNTC THERMISTOR 负温热敏电阻器 NTC THERMISTORNTC THERMISTOR MF71 POWER THERMISTOR 抑抑 制制 浪浪 涌涌 电电 流流 工工 作作 原原 理理 抑抑 制制 浪浪 涌涌 电电 流流 工工 作作 原原 理理 Inrush current limiting theory 开关电源、电机、变压器等设备，开机瞬间具有很高的浪涌电流， 部分元 器件可能因此而损伤甚至失效，在电路中串入MF71 型 NTC 热敏电 阻器， 可就以用很低的成本有效抑制浪涌电流。开机瞬间，热敏电阻处 于“冷”态具有较高的阻值，对浪涌电流进行有效抑制。随后由 于负载电流的作用使热敏电阻自身发热，阻值骤降 10～100 倍， 消耗功率减少。当下次开机时，热敏电阻器又自恢复成 “冷态”， 重复上述过程。 Many items of equipment like switch-mode power supplies, electric motors or transformers exhibit excessive inrush currents when they are turned on, meaning that other components may be damaged or fuses may be tripped. With NTC thermistors it is possible to effectively limit these currents, at attractive cost, by connecting a thermistor in series with the load. The NTC thermistors specially developed for this application limit the current at turn-on by their relatively high cold resistance. As a result of the current load heats up and reduces its resistance by a factor of 10 to 100; the power it draws reduces accordingly. its resistance becomes high when turned off and then repeats the course when turned on again. Basic circuit diagram for diode protection Typical example of an inrush protection circuit: Typical current-time curve 特点特点 FEATRUE ：： 特点特点 ：： 抑制浪涌电流能力强、稳态功耗低、残余电阻值小 阻值范围和电流范围宽广，系列全 strong inrush current limiting, small steady state power, small residual resistance, wide range of resistance and current. 应用范围应用范围 APPLICATION: 应用范围应用范围 转换电源、开关电源、UPS 电源、加热器、电子节能灯、电子整流器 电源电路、彩色显像管、白炽灯、卤素灯其它照明灯具的灯丝保护。 Inrush current limiting in switch powe