Third Order Longitudinal Mode Piezoelectric Ceramic Transformer for High-Voltage Power Inverter

Takeshi INOUE; Mitsuru YAMAMOTO; Shingo KAWASHIMA; Seiji HIROSE

Third Order Longitudinal Mode Piezoelectric Ceramic Transformer for High-Voltage Power Inverter

Takeshi INOUE, Mitsuru YAMAMOTO, Shingo KAWASHIMA, Seiji HIROSE

Full Text Views

0

Share
Cite this

Summary :

Low-profile, miniaturized and highly efficient power inverters are required to light up backlights, which include cold cathode fluorescent lamps (CCFLs), in color liquid crystal displays (LCDs), replacing conventional power inverters with electromagnetic transformers. The object of this study is to actualize a power inverter to which a novel multilayered piezoelectric ceramic transformer operating in the third order longitudinal mode is applied. The piezoelectric transformer has a symmetrical structure in the lengthwise direction and its generating part operates in a piezoelectric stiffened mode in order to increase both energy conversion efficiency and power density. This transformer has great advantages. Namely, all the electronic terminals in this transformer can be connected at the vibration nodes of the transformer, which contributes to the guarantee of stable transformer performances at high power operation, and this transformer is superior in impedance matching against the backlight load at steady state, because the output impedance of this transformer is much lower than that of conventional Rosen type transformers. Then a power inverter with the transformer was fabricated. In this power inverter, a separately excited oscillation circuit was adopted to drive the transformer with high efficiency, and the transformer drive frequency was controlled by detecting the backlight current in order to adjust the backlight luminance properly. As a result, the fabricated power inverter exhibited more than 90% overall efficiency and 4. 5-W output power, which is enough power to light up a 9. 4 inch color LCD, including the stray capacitance loss resulting from CCFL mounting. The luminance value on a light transmission plate of the backlight was more than 2000 cd/m².

Publication: IEICE TRANSACTIONS on Electronics Vol.E81-C No.7 pp.1128-1135

Publication Date: 1998/07/25

Publicized

Online ISSN

DOI

Type of Manuscript

Category: Ultrasonic Electronics

Cite this

Copy

Takeshi INOUE, Mitsuru YAMAMOTO, Shingo KAWASHIMA, Seiji HIROSE, "Third Order Longitudinal Mode Piezoelectric Ceramic Transformer for High-Voltage Power Inverter" in IEICE TRANSACTIONS on Electronics, vol. E81-C, no. 7, pp. 1128-1135, July 1998, doi: .
Abstract: Low-profile, miniaturized and highly efficient power inverters are required to light up backlights, which include cold cathode fluorescent lamps (CCFLs), in color liquid crystal displays (LCDs), replacing conventional power inverters with electromagnetic transformers. The object of this study is to actualize a power inverter to which a novel multilayered piezoelectric ceramic transformer operating in the third order longitudinal mode is applied. The piezoelectric transformer has a symmetrical structure in the lengthwise direction and its generating part operates in a piezoelectric stiffened mode in order to increase both energy conversion efficiency and power density. This transformer has great advantages. Namely, all the electronic terminals in this transformer can be connected at the vibration nodes of the transformer, which contributes to the guarantee of stable transformer performances at high power operation, and this transformer is superior in impedance matching against the backlight load at steady state, because the output impedance of this transformer is much lower than that of conventional Rosen type transformers. Then a power inverter with the transformer was fabricated. In this power inverter, a separately excited oscillation circuit was adopted to drive the transformer with high efficiency, and the transformer drive frequency was controlled by detecting the backlight current in order to adjust the backlight luminance properly. As a result, the fabricated power inverter exhibited more than 90% overall efficiency and 4. 5-W output power, which is enough power to light up a 9. 4 inch color LCD, including the stray capacitance loss resulting from CCFL mounting. The luminance value on a light transmission plate of the backlight was more than 2000 cd/m².
URL: https://globals.ieice.org/en_transactions/electronics/10.1587/e81-c_7_1128/_p

Copy

@ARTICLE{e81-c_7_1128,
author={Takeshi INOUE, Mitsuru YAMAMOTO, Shingo KAWASHIMA, Seiji HIROSE, },
journal={IEICE TRANSACTIONS on Electronics},
title={Third Order Longitudinal Mode Piezoelectric Ceramic Transformer for High-Voltage Power Inverter},
year={1998},
volume={E81-C},
number={7},
pages={1128-1135},
abstract={Low-profile, miniaturized and highly efficient power inverters are required to light up backlights, which include cold cathode fluorescent lamps (CCFLs), in color liquid crystal displays (LCDs), replacing conventional power inverters with electromagnetic transformers. The object of this study is to actualize a power inverter to which a novel multilayered piezoelectric ceramic transformer operating in the third order longitudinal mode is applied. The piezoelectric transformer has a symmetrical structure in the lengthwise direction and its generating part operates in a piezoelectric stiffened mode in order to increase both energy conversion efficiency and power density. This transformer has great advantages. Namely, all the electronic terminals in this transformer can be connected at the vibration nodes of the transformer, which contributes to the guarantee of stable transformer performances at high power operation, and this transformer is superior in impedance matching against the backlight load at steady state, because the output impedance of this transformer is much lower than that of conventional Rosen type transformers. Then a power inverter with the transformer was fabricated. In this power inverter, a separately excited oscillation circuit was adopted to drive the transformer with high efficiency, and the transformer drive frequency was controlled by detecting the backlight current in order to adjust the backlight luminance properly. As a result, the fabricated power inverter exhibited more than 90% overall efficiency and 4. 5-W output power, which is enough power to light up a 9. 4 inch color LCD, including the stray capacitance loss resulting from CCFL mounting. The luminance value on a light transmission plate of the backlight was more than 2000 cd/m².},
keywords={},
doi={},
ISSN={},
month={July},}

Copy

TY - JOUR
TI - Third Order Longitudinal Mode Piezoelectric Ceramic Transformer for High-Voltage Power Inverter
T2 - IEICE TRANSACTIONS on Electronics
SP - 1128
EP - 1135
AU - Takeshi INOUE
AU - Mitsuru YAMAMOTO
AU - Shingo KAWASHIMA
AU - Seiji HIROSE
PY - 1998
DO -
JO - IEICE TRANSACTIONS on Electronics
SN -
VL - E81-C
IS - 7
JA - IEICE TRANSACTIONS on Electronics
Y1 - July 1998
AB - Low-profile, miniaturized and highly efficient power inverters are required to light up backlights, which include cold cathode fluorescent lamps (CCFLs), in color liquid crystal displays (LCDs), replacing conventional power inverters with electromagnetic transformers. The object of this study is to actualize a power inverter to which a novel multilayered piezoelectric ceramic transformer operating in the third order longitudinal mode is applied. The piezoelectric transformer has a symmetrical structure in the lengthwise direction and its generating part operates in a piezoelectric stiffened mode in order to increase both energy conversion efficiency and power density. This transformer has great advantages. Namely, all the electronic terminals in this transformer can be connected at the vibration nodes of the transformer, which contributes to the guarantee of stable transformer performances at high power operation, and this transformer is superior in impedance matching against the backlight load at steady state, because the output impedance of this transformer is much lower than that of conventional Rosen type transformers. Then a power inverter with the transformer was fabricated. In this power inverter, a separately excited oscillation circuit was adopted to drive the transformer with high efficiency, and the transformer drive frequency was controlled by detecting the backlight current in order to adjust the backlight luminance properly. As a result, the fabricated power inverter exhibited more than 90% overall efficiency and 4. 5-W output power, which is enough power to light up a 9. 4 inch color LCD, including the stray capacitance loss resulting from CCFL mounting. The luminance value on a light transmission plate of the backlight was more than 2000 cd/m².
ER -