| 摘要 |
<p>PURPOSE:To simplify an operation by providing an impedance detecting circuit controlling the ON-OFF of the power source switch of a second electronic information equipment in accordance with the prescribed change of the output circuits of voice signal output circuits in the second electronic information equipment. CONSTITUTION:An electronic information device in which voice signals from first electronic equipments 1, 2 provided with voice signal output circuits are made to be transmitted to a second electronic equipment 4 via transmission lines L is provided. In this device, an impedance detecting circuit 5 controlling the ON-OFF of a power source switch 9 of the second information equipment 4 in accordance with the prescribed change of output impedances of voice output circuits is provided in the second information equipment 4. Thus, since even though a special control signal is not supplied from the first information equipments 12 to the second information equipment 4, when the first information equipment 1, 2 are made be in operating states, the power switch 9 of the second information equipment 4 is automatically operated, the operation by a user is easily performed.</p> |
