| 摘要 |
<p>PURPOSE:To effectively use an internal power source so that long time use can be attained by changing automatically the operating condition of a peripheral device by a processor so as to reduce power consumption when the internal power source is used. CONSTITUTION:When the output signal of a voltage detection circuit 13 is inputted to the input port PI of the processor 18, the processor 18 confirms the existence of an external power source, and outputs a confirmed result from an output port PO to a selector 20. Two kinds of clocks of high speed and low speed are inputted to the selector 20 from a clock source 19, and when the external power source exists, the high speed clock is selected for lap-top type terminal equipment 11, and the peripheral device 21 is operated by the high speed clock. On the other hand, when the external power source does not exist, the peripheral device is operated by taking in the internal power source by the low speed clock. Thus, the power consumption of the peripheral device can be changed automatically, and daily confirmation becomes unnecessary.</p> |
