| 摘要 |
<p>PURPOSE:To secure protection of the system working against the service interruption of a control power supply with use of a spare power supply of small capacity, by actuating the holding function of a microcomputer in case the service interruption of the control power supply lasts longer than a prescribed limit time. CONSTITUTION:The holding function of a microcomputer 31 of a control circuit 12 is actuated when the service interruption of a control power supply 18 lasts longer than a prescribed limit time. Therefore, the power supply 18 is backed up by a spare power supply 28 with no discontinuation of the system working of the computer 31 in case the power supply 18 has a service interruption less than the prescribed limit time. While the computer 31 stops the system working when the service interruption of the power supply 18 lasts longer than the limit time. At the same time, the computer 31 stores and holds the control states of circuits 37-39 to be controlled with low power consumption immediately before the system working is stopped. Thus, it is possible to protect the system working against the service interruption of the power supply by means of the power supply 28 of small capacity.</p> |
