PURPOSE: To obtain a switching regulator in which the operating mode can be set automatically and variably in accurate response to variation in the power consumption of a load by releasing the regulation when the ratio between the power consumption of a control means and the load power exceeds a predetermined upper limit.
CONSTITUTION: When the state of a load varies to cause increase or decrease of load power, a regulation means 15 compares the ratio of power consumption of a control means 13 and the load power with a lower limit, i.e. a first branch point and regulates the driving of a voltage conversion means 11 when the former is lower. Furthermore, an intermittent control means 14 compares the load power with a predetermined threshold value and drives the voltage conversion means 11 through the control means 13 when the former is lower otherwise repeats the operation for regulating the driving. When the load power increases, a regulation releasing means 16 compares a time rate or a frequency with a predetermined upper limit, i.e., a second branch point, and release the regulation when the former exceeds the latter. Consequently, the operation mode can be switched automatically in response to the variation in the power consumption of load accurately.
YANO HIDETOSHI
OZAWA HIDEKIYO
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