Patent ID: 7088080
Filing Date: 2006-08-08
Classification: G09G

Abstract:
1. A power supply circuit for a vacuum fluorescent display, comprising: an induction element which is provided in a current path to generate an induced voltage in accordance with a change in current flowing therein; an input terminal for a DC voltage to one terminal of said induction element; a switching element which is provided between the other terminal of said induction element and a ground line; a control circuit which periodically turns on/off said switching element; a boosting circuit which generates a boosted voltage on the basis of an induced voltage generated at the other terminal of said induction element when said switching element is switched from ON to OFF; a first terminal connected to a node between the other terminal of said induction element and said switching element; a second terminal to which a DC voltage lower than the induced voltage generated at the other terminal of said induction element is applied; and a variable resistor provided on a connection line between the first terminal and the node between the other terminal of said induction element and said switching element.