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NTC热敏电阻在变压器上电防浪涌中的应用-华巨电子
TC热敏电阻在变压器上电浪涌防护中的应用-华巨电子 问题陈述与提出： 变压器引起浪涌电流，浪涌电流超过了影响变压器铁芯磁性的饱和电流。甚至变压器的二次启动时无负载时也会发生。浪涌电流的大小取决于在变压器打开时的瞬时AC 波。如果这个瞬间正好是AC 电压波正在经历它的峰值，那么将没有浪涌电流产生。如果这样的话，浪涌电流的量将保持正常无负载值。如果这个瞬间正好是AC 电压波经历它的零值时，那么引起的电流将非常高而超过饱和电流（见图一）。这种情况下，变压器就必须受到保护不受浪涌电流的损坏。 
华巨电子变压器浪涌电流抑制保护方案： 此应用提供了一个方便的解决方案（图2）来处理变压器中浪涌电流超过饱和电流的问题。这个方案是用 NTC 热敏电阻与初级线圈串联。在开关打开时热敏电阻有个高阻值来抑制浪涌电流。短时间之后，NTC热敏电阻由于自热，阻值降低到一个很低的值而不影响正常工作。 
华巨电子提供的大功率NTC热敏电阻能够满足这一要求，其最大电流可以达到32A的稳态电流，在220V中功率可达7KW的的变压器提供浪涌保护功能。 具体参数参阅华巨电子SCD系列大功率热敏电阻：http://www.sinochip.net/ntcremin/scd.htm 每个额定变压器：1000VA,
每个变压器下降：30V 总额定变压器：2000VA 使用的滤波电容：30V,2300uF 5.主要技术参数
型号 | R25 | 最大稳态电流 | 25℃下最大电流时近似电阻值 | 片径Φ | 耗散系数 | 热时间常数 | 工作温度 | （Ω） | （A） | （Ω） | （mm） | （mW/℃） | （S） | （℃） | 芯片直径：(13-35)mm | -55～+250 | | SCD-10R01.7 | 10 | 1.7 | 0.031 | 5 | 8 | 60 | SCD-20R01 | 20 | 1 | 0.47 | 5 | 8 | 60 | | SCD-1R09 | 1 | 9 | 0.032 | 13 | 13 | 63 | | SCD-1R39 | 1.3 | 9 | 0.042 | 13 | 13 | 63 | | SCD-1R59 | 1.5 | 9 | 0.043 | 13 | 13 | 63 | | SCD-2R58-13 | 2.5 | 8 | 0.048 | 13 | 13 | 63 | | SCD-3R08 | 3 | 8 | 0.052 | 13 | 13 | 63 | | SCD-4R07 | 4 | 7 | 0.068 | 13 | 13 | 63 | | SCD-5R07 | 5 | 7 | 0.078 | 13 | 13 | 63 | | SCD-6R06 | 6 | 6 | 0.090 | 13 | 13 | 63 | | SCD-7R06 | 7 | 6 | 0.098 | 13 | 13 | 63 | | SCD-8R06 | 8 | 6 | 0.104 | 13 | 13 | 63 | | SCD-10R06 | 10 | 6 | 0.126 | 13 | 13 | 63 | | SCD-12R05 | 12 | 5 | 0.146 | 13 | 13 | 63 | | SCD-15R04 | 15 | 4 | 0.155 | 13 | 13 | 63 | | SCD-16R04 | 16 | 4 | 0.158 | 13 | 13 | 63 | | SCD-20R04 | 20 | 4 | 0.192 | 13 | 13 | 63 | | SCD-30R3.5 | 30 | 3.5 | 0.237 | 13 | 13 | 63 | | SCD-47R03 | 47 | 3 | 0.340 | 13 | 13 | 63 | | SCD-60R2.5 | 60 | 2.5 | 0.420 | 13 | 13 | 63 | | SCD-121R2.5 | 120 | 1.8 | 0.994 | 13 | 13 | 63 | | SCD-2R58-15 | 2.5 | 8 | 0.086 | 15 | 21 | 75 | | SCD-1R310 | 1.3 | 10 | 0.034 | 15 | 22 | 75 | | SCD-1R510 | 1.5 | 10 | 0.036 | 15 | 22 | 75 | | SCD-2R59.5 | 2.5 | 9.5 | 0.044 | 15 | 22 | 75 | | SCD-3R09 | 3.0 | 9.0 | 0.046 | 15 | 22 | 75 | | SCD-5R08 | 5.0 | 8.0 | 0.058 | 15 | 22 | 75 | | SCD-6R07 | 6.0 | 7.0 | 0.069 | 15 | 22 | 75 | | SCD-7R07 | 7.0 | 7.0 | 0.078 | 15 | 22 | 75 | | SCD-8R07 | 8.0 | 7.0 | 0.084 | 15 | 22 | 75 | | SCD-10R07 | 10.0 | 7.0 | 0.098 | 15 | 22 | 75 | | SCD-12R06 | 12.0 | 6.0 | 0.116 | 15 | 22 | 75 | | SCD-15R06 | 15.0 | 6.0 | 0.125 | 15 | 22 | 75 | | SCD-16R06 | 16.0 | 6.0 | 0.129 | 15 | 22 | 75 | | SCD-20R06 | 20.0 | 6.0 | 0.136 | 15 | 22 | 75 | | SCD-30R05 | 30.0 | 5.0 | 0.165 | 15 | 22 | 75 | | SCD-47R04 | 47.0 | 4.0 | 0.357 | 15 | 22 | 75 | | SCD-121R2.5 | 120 | 2.5 | 0.652 | 15 | 22 | 75 | SCD-0R716 | 0.7 | 16 | 0.026 | 20 | 29 | 110 | SCD-1R016 | 1.0 | 16 | 0.027 | 20 | 29 | 110 | SCD-1R020-20 | 1.0 | 20 | 0.020 | 20 | 29 | 113 | SCD-1R515 | 1.5 | 15 | 0.030 | 20 | 29 | 110 | SCD-2R014 | 2.0 | 14 | 0.035 | 20 | 29 | 110 | SCD-2R512 | 2.5 | 12 | 0.060 | 20 | 29 | 110 | SCD-2R513 | 2.5 | 13 | 0.055 | 20 | 29 | 110 | SCD-2R515 | 2.5 | 15 | 0.046 | 20 | 29 | 110 | SCD-3R012 | 3.0 | 12 | 0.040 | 20 | 28 | 110 | SCD-4R012 | 4.0 | 12 | 0.043 | 20 | 28 | 110 | SCD-4R712 | 4.7 | 12 | 0.046 | 20 | 28 | 110 | SCD-5R010 | 5.0 | 10 | 0.049 | 20 | 29 | 110 | SCD-5R012 | 5.0 | 12 | 0.047 | 20 | 29 | 110 | SCD-6R011 | 6.0 | 11 | 0.052 | 20 | 29 | 110 | SCD-6R810 | 6.8 | 10 | 0.055 | 20 | 29 | 110 | SCD-7R010 | 7.0 | 10 | 0.075 | 20 | 28 | 110 | | SCD-8R09 | 8.0 | 9 | 0.058 | 20 | 28 | 110 | SCD-10R08 | 10.0 | 8 | 0.085 | 20 | 29 | 110 | SCD-12R07.5 | 12.0 | 7.5 | 0.112 | 20 | 29 | 110 | SCD-15R07 | 15.0 | 7 | 0.123 | 20 | 29 | 110 | SCD-18R07 | 18.0 | 7 | 0.122 | 20 | 29 | 110 | SCD-20R06 | 20.0 | 6 | 0.132 | 20 | 29 | 110 | SCD-20R07 | 20.0 | 7 | 0.122 | 20 | 29 | 110 | | SCD-25R06 | 25.0 | 6 | 0.168 | 20 | 29 | 110 | | SCD-30R06 | 30.0 | 6 | 0.195 | 20 | 29 | 110 | | SCD-47R05 | 47.0 | 5 | 0.325 | 20 | 29 | 110 | | SCD-120R03 | 120.0 | 3 | 0.658 | 20 | 29 | 110 | SCD-0R522 | 0.5 | 22 | 0.017 | 25 | 30 | 130 | SCD-0R722 | 0.7 | 22 | 0.018 | 25 | 30 | 130 | | SCD-1R020-25 | 1.0 | 20 | 0.021 | 25 | 30 | 130 | SCD-1R519 | 1.5 | 19 | 0.024 | 25 | 30 | 130 | SCD-2R018 | 2.0 | 18 | 0.026 | 25 | 30 | 130 | SCD-2R516 | 2.5 | 16 | 0.029 | 25 | 30 | 130 | SCD-3R015.5 | 3.0 | 15.5 | 0.032 | 25 | 30 | 130 | SCD-4R015 | 4.0 | 15 | 0.039 | 25 | 30 | 130 | SCD-4R714 | 4.7 | 14 | 0.044 | 25 | 30 | 130 | SCD-5R014 | 5.0 | 14 | 0.047 | 25 | 30 | 130 | SCD-6R812 | 6.8 | 12 | 0.061 | 25 | 30 | 130 | SCD-7R011 | 7.0 | 11 | 0.064 | 25 | 30 | 130 | SCD-8R010 | 8.0 | 10 | 0.079 | 25 | 30 | 130 | SCD-10R010 | 10.0 | 10 | 0.084 | 25 | 30 | 130 | SCD-12R09 | 12.0 | 9 | 0.102 | 25 | 30 | 130 | SCD-15R08 | 15.0 | 8 | 0.117 | 25 | 30 | 130 | SCD-18R08 | 18.0 | 8 | 0.125 | 25 | 30 | 130 | SCD-20R08 | 20.0 | 8 | 0.132 | 25 | 30 | 130 | SCD-0R530 | 0.5 | 30 | 0.013 | 30 | 40 | 190 | SCD-1R030 | 1.0 | 30 | 0.014 | 30 | 40 | 190 | SCD-1R525 | 1.5 | 25 | 0.016 | 30 | 40 | 190 | SCD-2R023 | 2.0 | 23 | 0.019 | 30 | 40 | 190 | SCD-2R520 | 2.5 | 20 | 0.023 | 30 | 40 | 190 | SCD-3R019.5 | 3.0 | 19.5 | 0.026 | 30 | 40 | 190 | SCD-4R019 | 4.0 | 19 | 0.031 | 30 | 40 | 190 | SCD-4R718 | 4.7 | 18 | 0.035 | 30 | 40 | 190 | SCD-5R017 | 5.0 | 17 | 0.037 | 30 | 40 | 190 | | SCD-6R017 | 6.0 | 17 | 0.042 | 30 | 40 | 190 | SCD-6R816 | 6.8 | 16 | 0.043 | 30 | 40 | 190 | SCD-7R015 | 7.0 | 15 | 0.044 | 30 | 40 | 190 | SCD-8R014 | 8.0 | 14 | 0.049 | 30 | 40 | 190 | SCD-10R013 | 10.0 | 13 | 0.056 | 30 | 40 | 190 | SCD-12R012 | 12.0 | 12 | 0.067 | 30 | 40 | 190 | SCD-15R011 | 15.0 | 11 | 0.078 | 30 | 40 | 190 | SCD-18R010 | 18.0 | 10 | 0.092 | 30 | 40 | 190 | SCD-20R09 | 20.0 | 9 | 0.113 | 30 | 40 | 190 | SCD-0R532 | 0.5 | 32 | 0.010 | 35 | 55 | 280 | SCD-1R032 | 1.0 | 32 | 0.011 | 35 | 55 | 280 | SCD-1R528 | 1.5 | 28 | 0.013 | 35 | 55 | 280 | SCD-2R025 | 2.0 | 25 | 0.017 | 35 | 55 | 280 | SCD-2R523 | 2.5 | 23 | 0.020 | 35 | 55 | 280 | SCD-3R022 | 3.0 | 22 | 0.023 | 35 | 55 | 280 | SCD-4R021 | 4.0 | 21 | 0.026 | 35 | 55 | 280 | SCD-4R720 | 4.7 | 20 | 0.029 | 35 | 55 | 280 | SCD-5R019 | 5.0 | 19 | 0.030 | 35 | 55 | 280 | SCD-6R818 | 6.8 | 18 | 0.035 | 35 | 55 | 280 | SCD-7R017 | 7.0 | 17 | 0.037 | 35 | 55 | 280 | SCD-8R016 | 8.0 | 16 | 0.041 | 35 | 55 | 280 | SCD-10R015 | 10.0 | 15 | 0.045 | 35 | 55 | 280 | SCD-12R014 | 12.0 | 14 | 0.051 | 35 | 55 | 280 | SCD-15R013 | 15.0 | 13 | 0.060 | 35 | 55 | 280 | SCD-18R011 | 18.0 | 11 | 0.072 | 35 | 55 | 280 | SCD-20R010 | 20.0 | 10 | 0.089 | 35 | 55 | 280 |
注：若非特别指出,R25的允许偏差为±20%。 华巨电子热敏电阻厂家：www.sinochip.net
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网址:www.sinochip.net
技术支持:华巨电子