一种过压欠压保护器的分析及其新应用

当电网出现欠压或过压时，用电器往往无法正常运行，甚至遭到损坏。应用敏感于电网电压的基本特性，过压欠压保护器及时将用电器的电源切断，以保护用电器免受非常规电压的破坏。执行电路采用DC 48V继电器，绕组工作电流仅有5mA，有条件采用稳压二极管式并联稳压器、电容器降压和半波整流，简化了电路结构，也节省了制作成本。将过压欠压保护器与补偿变压器连接起来，就成为一台既小巧又经济实用的欠压自动补偿器，在确保用电器安全可靠运行的同时，其耗电量大大低于稳压器，且无波形畸变及电磁污染，符合当前节能增效的科学发展观。

Analysis of a Kind of Overvoltage or Undervoltage Protector and Its New Application

When power network is overvoltage or undervoltage, electrical appliance will not work normally, or even would be destroyed. Because of its sensitivity to voltage of power network, an overvoltage or undervoltage protector will cut offthe power of electrical appliance to protect it from being destroyed by abnormal voltage. The executive circuit of the protector adopted a relay whose working voltage was 48V DC at 5 mA working current. The usage of voltage regulator, dropping capacitor and half wave rectification will simplify the structure of the circuit and reduce its cost. Connecting the overvoltage or undervoltage protector with a compensator transformer will make a smart and cost-effective undervoltage autocompensator. The autocompensator ensures electrical appliance working safely when its power dissipation is less than constant voltage regulator without wave distortion and electromagnetic pollution, which is in keeping with the scientific outlook on development about saving energy and improving efficiency.