| 摘要 |
<p>The invention provides an alarm device for a bus connected alarm system comprising a bus connection unit 17 for connecting the alarm device with a bus 3 for supplying control signals and an electric power, a power consuming unit 11, 15, a controller 21 for controlling the operation of the alarm device (1) based on the control signals. Furthermore, the alarm device comprises an energy storage unit for storing electrical energy, a switching unit 25 for switching between a first power supply mode, where power is supplied through the bus 3 alone, to a second power supply mode where at least part of the power is supplied through the energy storage unit 5, wherein the controller 21 is configured to control the switching unit 25 so as to switch to the second power supply mode, when the power consuming unit 11, 15 is activated.</p> |
