基于智能家居控制电路弱电保护电路设计

随着物联网技术广泛运用,智能家居以及智慧社区的开展,弱电控制器广泛应用于室内家用电器以及室内外传感器的控制。所设计的弱电控制器或通信模块的电源线或信号线易受到市电(220 VAC)的影响,从而导致电路后端芯片软损坏或直接损坏。设计了适用于智能家居控制系统后端控制器及通信模块中的低压保护电路。通过实验测试,进行直流过载以及交流干扰测试均具备电路保护作用。

Study on the instantaneous protection reliability of low voltage circuit breakers

This paper outlines the significance of enhancing the instantaneous protection reliability of low voltage circuit breakers and describes their main failure modes. The instantaneous failure mechanism of low voltage circuit breakers was analyzed so that measures to improve instantaneous protection reliability can be determined. Furthermore, the theory of the instantaneous characteristics calibration device for low voltage circuit breakers and the method of eliminating the non-periodic component of test current are given in detail. Finally, the test results are presented.

售后服务谈经验——长虹彩电维修随笔(二)

故障现象4:光栅缩小,图像暗。检修方法:测量电源115 V输出电压只有58 V,检查负载电路正常。说明振荡电路和待机工作控制电路也能正常工作。重点检查超低压保护电路。首先,测量VQ838基极电压为-0.7 V(正常值为1.4 V),同时检查发现R868电阻开路。VQ838是超低压保护电路的取样放大管,当交流输入电压低于90 V时,由R868和R869分压而取得的VQ838基极电压也较低。