如果你想测试一下你的应答机,你必须将它连在你的电话线上,而且有人打电话给你方可。本文介绍的盒子电话公司(简称TCB)可解决这个问题。将两部电话插入TCB。当两部电话都挂机时,TCB向两部电话提供24V线电压。当某一部电话摘机 If you want to test your answering machine, you have to connect it to your telephone line and someone can call you. This article describes the box telephone company (referred to as TCB) to solve this problem. Insert two phones into the TCB. When both phones are on-hook, the TCB provides 24V line voltage to both phones. When a certain phone goes off-hook