| 摘要 |
PURPOSE:To prevent the confusion due to a setting error and the loss of a short plug by automatically performing a mode switch by using the slave machine of a cordless telephone set, utilizing the installation and non-installation state of the slave machine with a master machine and without using the short plug. CONSTITUTION:The comparator 15 of a master machine 1 fetches voltage VA and VB that each voltage of the B terminal of a power source Vcc and the A terminal of a charging terminal 17 is divided by resistances R1 to R5 in + input and - input of an AMP 1 and compares them. In this case, voltage VA>VB or voltage VA<VB is depending on whether a slave machine 2 is in the setting or non-setting state to the master machine 1 and an AMP 15 imparts a signal L or H to a master machine microcomputer 14. By this signal L or H, the microcomputer 14 controls each circuit in the internal part of the master machine so as to set a test mode A or B. Thus, the switching of the test modes A and B is automatically performed without the switching setting of a changeover switch and a short plug and a confusion due to a setting error and the loss of a short plug can be prevented. |
