| 摘要 |
<p>To control a converter of a satellite receiving system the converter receives not only a dc voltage but one of two different voltages (normally 13 or 17 volt), also an alternating voltage (normally 22 kHz). It has to be possible to control more equipment along the same (coax) cable like amplifiers and switchers and to switch between more sub-bands than two. To achieve this the satellite receiver comprises a power supply unit having switching means which can combine the supplying of one of the two dc voltages with an alternating voltage continuous tone or burst as (switching) information.</p> |
