| 摘要 |
<p>A coupling device that implements a related method for remote powering wide band digital telecommunication devices through telephone lines or coaxial cables installed in all buildings, has an AC blocking transistor inserted in the electrical path from a voltage supply line to the telephone line or coaxial cable. The transistor has a first current terminal coupled to the supply line and a second current terminal coupled to the telephone line, and it is controlled with a DC control voltage such to keep it in a substantially linear functioning condition at the edge of a saturation condition during the normal functioning whatever the supply current that flows through the transistor is, destined to the connected telecommunication devices. This may be done by properly generating this control voltage by means of a dedicated voltage generator, or by nullifying the DC component of the difference of potential between the control terminal and the second current terminal, for example through a low-pass filter that generates the voltage on the control terminal as a low-pass replica of the voltage on the second current terminal.</p> |
