Patent ID: 6191962
Filing Date: 2001-02-20
Classification: H02M

Abstract:
A step-up power supply circuit comprising:a first rectifying element and a first capacitive element series-connected between a first contact point and a second contact point;a second rectifying element connected between a joint point between said first rectifying element and said first capacitive element, and a third contact point;a second capacitive element connected between said third contact point and a fourth contact point; anddrive means for outputting a signal having a waveform whose amplitude is not rapidly changed, but becomes constant every predetermined time period;wherein plural sets containing said first/second rectifying elements and said first/second capacitive elements are cascade-connected to each other in a plurality of stages; andwherein said first contact point of a post-staged set is connected to said third contact point of a pre-staged set; said second contact point is commonly connected; a predetermined power supply voltage is applied to said first contact point of a topmost-staged set; the signal of said drive means is supplied to said second contact point of the topmost-staged set; and said fourth contact point is set to a lower voltage than said predetermined voltage.