直流24V的电器正负极是否可以接反不能一概而论,根据直流电器输入端的极性保护电路的形式,有下列3种情况:
极性接反将烧毁用电器:此类直流电器在输入端没有设计极性保护电路,在电源输入端标注“+”“—”。接线时必须严格按照标注极性接线,接错会烧毁或击穿电器内部的电子元器件。示意图如下
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/00e93901213fb80e608e096430d12f2eb9389421?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
极性接反电器不工作:此类直流电器在输入端串接一只整流二极管,构成最简单的极性保护电路。若电源极性接反时,二极管截止,用电器断电,从而保护用电器。示意图如下
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/a71ea8d3fd1f4134c64c6dcd231f95cad1c85e0d?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
极性接反电器正常工作:在输入端接有整流桥电路,构成无极性输入。无论外部电源极性是否接反,整流桥都会将外部电源极的性按照设计极性输入直流电器。示意图如下
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/0e2442a7d933c895572ef3c8d71373f082020034?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)