| 摘要 |
PURPOSE:To extend service life of a spare equipment by bringing a spare set normally to power supply interruption or pre-heating state and providing a service life detecting means of an active set so as to setting the spare set in the operating state based on a detection signal. CONSTITUTION:The active set 6 is provided with the service life detecting means 10 and the said detection signal is inputted to a switch means 4. When the active set 6 is in use, the switching means 4 applies power to the active set 6 and the power of the space set 8 is interrupted or the set 8 is brought into the pre-heating state. When the active set 6 is used for a long time, the service life detecting means 10 detects the service life of the active set 6 to give a signal to the switching means 4. The switching means 4 applies the power to the space set in response to the said signal to bring the space set in the normal operating state. |
