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Patent Searching and Data


Title:
TALKING SYSTEM
Document Type and Number:
Japanese Patent JPH04329053
Kind Code:
A
Abstract:

PURPOSE: To use a power on/off switch in the operation of a press-to-talk button in common for a transmission reception changeover switch.

CONSTITUTION: A press-to-talk interphone system 5 consists of a slave set 6 and a master set 7. When transmission reception changeover switches SW11, SW12 provided in the master set 7 are operated, a potential at an output terminal of an inverter 75 goes to a high level, an NPN TR Q52 is turned on, a PNP TR Q51 is turned on and a power supply voltage is supplied to an amplifier 73. In this state, one output terminal of a speaker 74 in common use for a microphone is connected to an input terminal of the amplifier 73 and an output terminal of the amplifier 73 connects to one input terminal of a speaker 64 in common use with a microphone, then the speaker 74 in common use with a microphone of the master set 3 is in the transmission state and the speaker 34 in common use with a microphone of the slave set 2 is in the reception state. Thus, the switch for power supply ON/OFF in the operation of the press- to-talk button is in common use for transmission reception changeover switches SW11, SW12.


Inventors:
MATSUDA MITSUHIRO
Application Number:
JP1991000098946
Publication Date:
November 17, 1992
Filing Date:
April 30, 1991
Export Citation:
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Assignee:
TOSHIBA LIGHTING & TECHNOLOGY
International Classes:
H04M9/00; (IPC1-7): H04M9/00