| 摘要 |
PROBLEM TO BE SOLVED: To make a regulated power unit for cordless electronic equipment to cope with the large fluctuation of a load current and, at the same time, to improve the utilization efficiency of the capacity of a battery regardless of the fluctuation in the load current. SOLUTION: A series-type regulator 10 and a switching-type regulator, incorporating a field effect transistor 21 and an inductor 23, are compounded and interposed between a battery 1 and loads composed of a microcomputer 2 and an electronic circuit 4. The magnitude of a load current is discriminated by means of a resistor 31 and a voltage drop detecting circuit 33, and transistors 35 and 36 and an AND gate 37 are turned on or off according to the magnitude of the load current. By turning on or off the transistors 35 and 36 and an AND gate 37, only the series-type regulator 10 having low internal heat loss is operated when the load current is small, and the high-efficiency switching-type regulator is operated in addition to the regulator 10 when the load current is large. |
