| 摘要 |
<p>A battery (+V) operable information handling and control system, for example for an automotive vehicle electrical system, has a central unit (10) and a number of remote units (20) each connected to the central unit (10) by a respective signalling link (40). The central unit (10) includes processing and control means (13) and power supply means (11) which are turned on to operate the processing and control means (13) in an active mode of the system and are turned off in a sleep mode of the system. During the active mode the processing and control means (13) applies a clock pulse voltage to a data line (41) in each signalling link (40). One of the clock pulse lines (41) is connected to power supply control means (12) in the central unit (10) and to activation voltage drive means (80) in the respective remote unit (20). When the system is in the sleep mode the activation voltage drive means (80) can be enabled by operation of a activation switch (60,61) connected to that remote unit (20) so as to apply to that clock pulse line (41) an activation voltage, substantially the battery +V voltage (12 volts) and lower than the clock pulse voltage (30 volts). The power supply control means (12) is enabled by the activation voltage so as to turn on the power supply means (11) and the activation voltage drive means (80) is then disabled responsive to the clock pulse voltage consequently applied at the start of the active mode.</p> |
