| 摘要 |
PURPOSE:To enable failure of a magnet switch contact to be recognized by comparing a data which is obtained by a data detection means with that read out by a data memory means and then by controlling ringing of a buzzer or a chime. CONSTITUTION:A data corresponding to a voltage between terminals of a battery 7 is written before a timer unit 15 times up. When the timer unit 15 times up, a magnet switch 1 is turned off. Then, after a certain amount of time passes, a data corresponding to a voltage between terminals of a battery 7 is detected. Then, this detection data and data which is written into the memory are compared. And then, when the difference is less than 1V, a buzzer or a chime which is not listed in the figure is rung. thus giving a warning that a contact of the magnet switch 1 malfunctions. |
