电话线路定时控制器朱建坤功能特点１．有效控制电话线路被普通用户超时占用。利用定时控制电路，可确保普通用户在拨打或接听电话的时间不能超过设定的时间（设计在３分钟），一旦超时，电话线路将被自动切断。而对有权用户，若需超时使用，则只要用电话机拨号键输人一组... Telephone line timing controller Zhu Jiankun Features 1. Effective control of telephone lines overtime occupied by ordinary users. The use of timing control circuit to ensure that ordinary users make or receive calls time can not exceed the set time (designed in 3 minutes), once the timeout, the telephone line will be automatically cut off. For the right users, for overtime use, as long as the dial-in phone dial a group of ...