| 摘要 |
<p>The electric power unit of the present invention for a battery-powered electronic appliance comprises a chopper-controlled nonisolated DC-DC converter (2) for converting the output voltage of a battery into a required voltage, a bypass switch (4) for bypassing the DC-DC converter, a comparator (5) for comparing the output voltage of the battery with a reference voltage (Vb) corresponding to the required voltage of the load circuit, and a controller (6) for controlling the bypass switch (4) on the basis of the output signal of the comparator (5). When the output voltage of the battery is higher than the reference voltage, the battery is connected directly to the load circuit, so that the power of the battery can be supplied to the load circuit without loss due to the operation of the DC-DC converter (2). When the output voltage is lower than the reference voltage, the output voltage of the battery is converted into a voltage nearly equal to the required voltage of the load circuit by the DC-DC converter (2), so that substantially all the energy stored in the battery (1) can effectively be used. <IMAGE></p> |
