设计开关电源时经常用到隔离变压器，这份文档可以告诉你如何设计隔离变压器-The design of switching power supplies often use isolation transformers, the document can tell you how to design the isolation transformer
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001002s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.073051s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.000814s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001160s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001055s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003623s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000786s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003791s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015350s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.000999s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 162883 [ RunTime:0.015518s ]
