Title:
CIRCUIT AND METHOD FOR DRIVING PIEZOELECTRIC TRANSFORMER
Document Type and Number:
Japanese Patent JP3139432
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To prevent the occurrence of abnormal resonance of a piezoelectric transformer by driving a drive circuit which drives the transformer in a frequency range, in which the transformer indicates a high efficiency and which is higher than the frequency at which the load current becomes the maximum and, at the same time, functions to prevent the over-vibration of the transformer without stopping the voltage outputted to the transformer.
SOLUTION: A piezoelectric transformer 102 is driven by connecting a drive circuit 101 to the primary electrode 102 of the transformer 102 and amplifying a sweep frequency signal from a frequency sweep oscillator 105 to a waveform required for the drive of the transformer 102. Since the transformer 102 is composed of a tertiary Rosen-type piezoelectric transformer which utilizes resonant operations at a frequency, which is three times as high as the mechanical resonance frequency determined by the shape of the transformer, the occurrence of the abnormal resonance or unnecessary resonance of the transformer can be prevented by limiting the sweeping range of the frequency to ≤±20% with respect to the frequency which is three times as high as the fundamental frequency of the transformer 102.
Inventors:
Shingo Kawashima
Application Number:
JP33562897A
Publication Date:
February 26, 2001
Filing Date:
December 05, 1997
Export Citation:
Assignee:
NEC
International Classes:
G02F1/133; H01L41/107; H02M11/00; (IPC1-7): H01L41/107; G02F1/133; H02M11/00
Domestic Patent References:
| JP6167694A | ||||
| JP564436A | ||||
| JP5176530A | ||||
| JP461798A | ||||
| JP4210773A | ||||
| JP5671472A | ||||
| JP833350A | ||||
| JP8107678A |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)