| 摘要 |
<p>A portable information terminal (100) comprises heavy loads (140), light loads (150), a first control unit (110), and a second control unit (120). The first control unit (110) measures the output voltage of a secondary cell (105) and controls the power feed to the heavy loads (140) by operating a first switch (S1). The first control unit (110) outputs, when stops the power feed to the heavy loads (140), a low-level control signal (CC) to a second control unit (120). The load of driving the second control unit (120) is less than the load of driving the first control unit (110). The second control unit (120) starts, upon receiving the control signal (CC), measuring the output voltage of the secondary cell (105). If the second control unit (120) detects a fall of the output voltage below a predetermined threshold voltage, it stops the power feed to the switch light loads (150) and the first control unit (110).</p> |
