| 摘要 |
PURPOSE:To prevent the data receiving or the like of the center side from being affected by fluctuation in current consumption, if any, by receiving a DC component of a current transmitted from an exchange side via a constant voltage circuit. CONSTITUTION:A constant current i0 flows always to a constant current diode CiD, a component i1 of the current flows to a terminal circuit 41 as a power supply current and the rest i2 flows to a Zener diode ZD2. Further, if the current i1 flowing to the terminal circuit 41 is fluctuated depending on the operating state of various circuit elements in the circuit 41, the fluctuating component is absorbed by the current i2 flowing to the Zener diode ZD2 and the current i0 flowing to the diode CiD is constant at all times. Thus, even if the current consumption in the circuit 41 is fluctuated, since the current flowing to the diode CiD is in constant and not pulsated, the fluctuation does not give adverse effect on the data receiving or the like at the center side. |
