【正文】 (or buzzer) as an alarm sound (at) the same time with the red signal (at the same time with the red signal lamp), and returned to normal when the bell HA as prompt sound. Can produce two distinct alarms and prompt sound effects. 濱州學(xué)院專 科畢業(yè)設(shè)計 (外文翻譯 ) 5 智能雙電源 1 智能雙電源切換的技術(shù)方案 本文所述的雙負載 — 雙電源自動切換的 PLC控制 ,用 PLC控制程序取代繼電器邏輯控制電路 ,其具有對三相供電電源的缺相檢測及保護切換功能 ,在電源恢復(fù)正常后能自動進行反切換 ,當發(fā)生故障和恢復(fù)正常時能分別發(fā)出兩種區(qū)別明顯的報警和提示音響。 similarly, the threephase power supply U2 A, B phase and C phase lack detection, but also the use of an intermediate relay KA4, KA5 and KA6, respectively connected to power the U2 main circuit A2, B2 phase and C2 phase and zero line N constitute a singlephase circuit, the formation of A2, B2 and C2 threephase openphase detection circuit. KA4 ~ KA6 normally open contacts respectively as U2 threephase openphase detection switch sampling signal, to the PLC input terminal, used in the 濱州學(xué)院專科畢業(yè)設(shè)計 (外文翻譯 ) 4 preparation of PLC U2 threephase openphase detection logic control program input conditions. 3 With PLC intelligent dual power control The threephase openphase detection signal sampling circuit, as U1 and U2 threephase openphase detection switch sampling signals of KA1KA3 and KA4KA6, the normally open contacts respectively for the input of the PLC X0X2, X3X5. In the PLC ladder diagram program, auxiliary relay R1 as the threephase power supply of U1 threephase openphase detection, which is normally open input conditions for X0, X1 and X2 and logic。兩路三相電源的主回路中每一相均有電流表指示濱州學(xué)院?？飘厴I(yè)設(shè)計 (外文翻譯 ) 6 各相電流的狀況 ,以配合控制電路的缺相檢測。 控制電路采用電笛 (或蜂鳴器 )作為報警音響 (同時配以紅色信號燈 ),而恢復(fù)正常時采用電鈴 HA 作為提示音響。 電源 U1 主回路通過交流接觸器 KM1 的主觸點閉合與其負載 W1 相聯(lián)接 。 in the event of a failure and return to normal when respectively sends out two difference obvious alarm and prompt sound effects. It overes the shortings of low double power supply switching control system without phase protection, can automatically reverse switch, as well as fault and return to normal when using a single audio prompts defects. The control system has perfect functi