| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply device which can stably drive a large discharge lamp and in which the primary side and the secondary side are insulated, which is space-saving and of low cost. SOLUTION: The power supply device comprises a first piezoelectric transformer 1 for inputting from the primary side electrode 2 and outputting to a load 4 from the secondary side electrode 3, in which a primary side electrode 2 is insulated from a secondary side electrode 3; a second piezoelectric transformer 11 in which a primary side electrode 12 and a secondary side electrode 13 for inputting to the primary side electrode 12 and outputting to the other terminal of the load 4 from the secondary side electrode 13 are insulated; a detection circuit 5 detecting the current flowing between the input terminal connected to the secondary side electrode 3 and the output terminal connected to the load 4 by a means which is insulated in terms of direct current; a control circuit 6 which controls the drive condition of the first piezoelectric transformer 1 by receiving the detection output; a drive circuit 7 which outputs to the primary side electrode 2 and a phase inversion circuit 9 by receiving output of the control circuit 6; and the phase inversion circuit 9 which outputs to the primary side electrode 12 of the second piezoelectric transformer 11 by receiving output of the drive circuit 7 and inverting 180°its phase. COPYRIGHT: (C)2007,JPO&INPIT |
