| 摘要 |
<p>PURPOSE: To supply a voltage to a load part like a liquid crystal display part only at the time of driving by providing a voltage switching part and controlling the voltage switching means by the control signal which switches two batteries to series connection and parallel connection. CONSTITUTION: When an electronic pocketbook 100 is in the driven state, a CPU 12 outputs a control signal of 0V. Therefore, a Pch 5 is turned on, and first and second batteries 1 and 2 are connected in series. Consequently, the potential at a point A is 6V. Since a Pch 8 is turned on and an Nch 9 is turned off, VDD1 being the output of a voltage switching means 7 is 6V, and 6V voltage is supplied to an LCD 10 and an LCD driver 11 so that it can be operated. When the electronic pocketbook 100 is in the non-driven state, the CPU 12 outputs 3V control signal. Then, the Pch 5 is turned off, and first and second batteries 1 and 2 are connected in parallel. Consequently, the potential at the point A is 3V, and the Pch 8 is turned off and the Nch 9 is turned on, and VDD1 is 0V.</p> |
