于是决定对该机进行简单改造,方案是改为单管IGBT,用2只英飞凌K75T60来驱动。要用IGBT改,就得先改造驱动脉冲变压器,于是用罐型磁芯重新绕制了一个16:30:30的脉冲变压器,再把脉冲整形电路上的2只串联限幅稳压二极管IN4745去掉,改用双向限幅二极管16KE.门极电阻改为15R。脉冲变压器原边供电断原来是通过1只10R的电阻接+15V,装上重新绕制的脉冲变压器后,发现波形的顶部不平,成馒头形波,于是将10R电阻上并联1只1R电阻后,波形就变得比较理想了。最后装上IGBT,再将功率板用酒精清洗干净刷上绝缘漆后上电试机,给定开到最大,表头显示110A,按实际这算大约90A。就把最大电流设定调整到表头显示180A,这样折算下来实际电流有130多A。经连续的试焊,效果很理想,再把钨极直接短路按下开关测试短路电流,在给定最大的情况下,表头指针已超过表头最大量程,在此状态下短路10几秒机器没有发生爆管。
![](http://u.dianyuan.com/upload/bbs/2010/01/27/1264569679-169345.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
![](http://u.dianyuan.com/upload/bbs/2010/01/27/1264569736-169346.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
![](http://u.dianyuan.com/upload/bbs/2010/01/27/1264569762-169347.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
![](http://u.dianyuan.com/upload/bbs/2010/01/27/1264569776-169348.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
![](http://u.dianyuan.com/upload/bbs/2010/01/28/1264682130-170223.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)
![](http://u.dianyuan.com/upload/bbs/2010/01/28/1264682061-170222.jpg?x-oss-process=image/watermark,g_center,image_YXJ0aWNsZS9wdWJsaWMvd2F0ZXJtYXJrLnBuZz94LW9zcy1wcm9jZXNzPWltYWdlL3Jlc2l6ZSxQXzQwCg,t_20)