500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/63/52531205767452.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20');}" onmousewheel="return imgzoom(this);">东芝S7变频功率板原理图
东芝S7变频器功率板原理图包括开关电源和功率主电路及模块脉冲驱动.主电路母线电压检测是利用开关变压器正激期间传递,整流成负电压,再与+5V相加,经CN2A-11送至CPU A/D转换,这样0V对应母线电压最高电压,+5V对应母线电压为0V.当Q11 2SK1317击穿时,在CN2A-11产生很高负电压,致使CPU A/D脚永久性损坏,导致整个变频器报废.只要在CN2A-11对地接一个二极管,箝位在-0.6V就能避免高负电压进入CPU A/D脚.箝位二极管普遍用在I/O控制输入回路.至今我还不明白,这是东芝设计人员的疏忽?! 52531205767328.pdf 500) {this.resized=true; this.width=500; this.alt='这是一张缩略图，点击可放大。\n按住CTRL，滚动鼠标滚轮可自由缩放';this.style.cursor='hand'}" onclick="if(!this.resized) {return true;} else {window.open('http://u.dianyuan.com/bbs/u/63/52531205767452.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20');}" onmousewheel="return imgzoom(this);">
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