| 摘要 |
PROBLEM TO BE SOLVED: To realize remote maintenance and to prevent the malfunction of a device by detecting voltage fluctuation based on a load which is set in a pseudo load generation circuit. SOLUTION: Load data is generated to the pseudo load generation circuit 5 from CPU 2 and the use time of a battery 4 is operated against a voltage fluctuation value by the pseudo load in CPU 2. The time of the life of the battery 4 is calculated and it is warned by a display device. When the voltage fluctuation value against the pseudo load becomes not more than 1.2V and a calculation result in CPU 2 becomes 'The life of battery already expires', whether the content of RAM 1 is destroyed or not is checked. When the content of RAM 1 is judged to be destroyed, precise data is written into RAM 1 and the system moves to a constant operation. When an abnormal state such as a power cut occurs, a switch S2 is turned on, backup voltage V2 is supplied through the pseudo load generation circuit 5 and a diode D2 and the content of RAM 1 is kept without being destroyed. |
