| 摘要 |
PURPOSE:To avoid the unnecessary loss of consumption power, by controlling a switching regulator based on output signal from a rotational speed discriminating circuit. CONSTITUTION:From a rotational speed discriminating circuit 7, the output of the comparing signal of reference signal with output signal from a speed detecting element 6 is directed to a control voltage generating circuit 8. Then, control voltage VREG from the control voltage generating circuit 8 is applied to a switching regulator 2A, and output voltage from the switching regulator 2A is changed. In this case, a switching transistor is ON/OFF-worked, and so it is not worked as a great voltage drop element, and accordingly, the generation of an unnecessary power loss is extremely reduced. |
