PURPOSE: To increase a call current, by connecting a local supply circuit to a telephone line via a bidirectional rectifying circuit, in a telephone set combinedly provided with the local power supply circuit.

CONSTITUTION: When an 8-common trunk PLT calls out a called 8-common telephone set PT, a selection signal TR is operated and a DC voltage -V1 is fed to a channel auxiliary device AD2 at the same time. But, since a diode D1 is present, no selection signal is stopped but an alarm device SD is energized. Further, when a called 8-common telephone set PT responds, the selection signal is stopped. In a calling state, a local call current I2 is increased with a local power supply circuit for a telephone set T.