| 摘要 |
PURPOSE:To back up the power supply with low power consumption without losing substantial functial fuction of unit, by performing the backup of power supply through the detection of power failure of AC power input and cutting off all the output port signals having much power consumption at the same time. CONSTITUTION:If the AC power input 2 is in failure, the power supply backup circuit 8 draws power supply from the battery 7, and supplies power to the microcomputer control section 12 through the constant voltage circuit 10. Simultaneously, at the control section 12, the power failure deciding routine C decides the adsence of AC waveform at the input port 22 checked at the check routine B and detects the power failure, and in this case, the output to the 1st output port 26 to the digital display section 16 comparatively much in the power consumption in the output limit routine is inhibited and the output limit routine f inhibits the output to the 3rd output port 30 to the control output section 20. |
