| 摘要 |
PURPOSE:To hold the state of a CPU or the data in a memory as long as possible by prolonging the duration of effective voltage region for a load circuit when a battery is removed or consumed in a battery drive appliance. CONSTITUTION:A power supply circuit 14 having output voltage, which can be switched between high and low levels, is connected with a battery 10 and a parallel circuit of a high resistor 18 and a switching element 16 is connected in series with an electric double layer capacitor 20, and the series circuit is connected in parallel with the battery on the output side of the power supply circuit. Prior to exchange of the battery, the power supply circuit is switched to high voltage output and the switching element is conducted thus charging the electric double layer capacitor quickly and when the battery is removed, power is fed through a rectifying diode 22 to a load circuit. |
