A Electrical Characteristics of Disk-type Piezotransformer with Electrode Ratio of Driving and Generating Part

디스크형 압전변압기의 전극비에 따른 전기적 특성

  • 이종필 (광운대 공대 전기공학과) ;
  • 채홍인 (주성대 전자신소재공학과) ;
  • 정수현 (대원과학대 전기전자과) ;
  • 홍진웅 (광운대 전기공학과)
  • Published : 2003.10.01


In order to develope piezoelectric transformer for the ballast of fluorescent lamp, a new shape and electrode pattern of piezoelectric transformer has been investigated in this work. The composition of piezoelectric ceramics was 0.95Pb(Zr$_{0.51}$Ti$_{0.49}$)O$_3$+0.03Pb(Mn$_{1}$3/Nb$_{2}$3/)O$_3$+0.02Pb(Sb$_{1}$2/Nb$_{1}$2/)O$_3$. The sample prepared by this composition system showed the characteristics which has about 1200 of relative dielecric constant, 1100 of the mechanical quality factor, 0.53 of the electromechanical coupling coefficient, 320 pC/N of the piezoelectric constant d$_{33}$, 0.3 % of the dissipation factor. Diameter and thickness of disk-type piezoelectric transformer was 45 mm and 4 mm, respectively. The driving and generating electrode with their gap of 1mm were fabricated on the top surface. But the common electrode was fabricated on the whole bottom surface. The electrode surface ratio of driving and generating part on the top surface ranges from 1.4:1 to 3:1. We investigated the electrical characteristics with the variation of the electrode surface ratio of driving and generating part in the range of load resistance of 100 $\Omega$~70 k$\Omega$. The set-up voltage ratio of this piezoelectric transformer increases with increasing both the electrode surface of driving part and the load resistance. The set-up voltage ratio at no load resistance was more than 60 times. On the other hand, the efficiency decreases with increasing the electrode surface of driving part. In the case of the electrode surface of both 1.4:1 and 2:1, maximum efficiency showed above 97 % at load resistance of 2 k$\Omega$. However, in the case of the electrode surface of 3:1, maximum efficiency showed about 94 % at load resistance of 3 k$\Omega$.>.>.>.


piezoelectric transformer;piezoelectric ceramic


  1. Masatosi Imori, Takashi Taniguchi and Hiroshi Matsumoto, 'A Photomultiplier High-Voltage Power Supply Incorporating a Ceramic Transformer Driven by Frequency Modulation', IEEE Transactions on Nuclear Science, Vol.45, No.3, 1998 https://doi.org/10.1109/23.682635
  2. Katsutoshi Sakurai, Kazumasa Ohnishi and Yoshiro Tomikawa, 'Presentation of a New Equivalent Circuit of a Piezoelectric Transformer under High-Power Operation', JJAP, Vol.38, No.9B, pp.5592-5597, 1999 https://doi.org/10.1143/JJAP.38.5592
  3. Sakurai K, Shindou S, Ohnishi K, and Tomikawa Y, 'Characteristics of a 1st Radial-Vibration-Mode-Disk Coupler-type Piezoelectric Ceramic Transformer, JJAP Part 1-Regular Papers Short Notes & Review Papers, Vol.37, No.9B, pp.5326-5329, 1998 https://doi.org/10.1143/JJAP.37.5326
  4. Hoy-Seung Jeong, Byung-Cheul Choi, Ju-Hyun Yoo, In-Ho IM and Chang-Yup Park, 'Pararell Driving of Piezoelectric Transformers', JJAP Part 1, Vol.38, No.9A, pp.5166-5169, 1999 https://doi.org/10.1143/JJAP.38.5166
  5. Yasuhiro Sasaki, Koichi Zama, Atsushi Ochi, Mitsuru Yamamoto, Susumu Saito, 'Multilayer Piezoelectric Transformer for 10W Use', NEC Technical Report, Vol.51, No.10, pp.81-84, 1998
  6. Fuda Y, Kumasaka K, Katsuno M, Sato H and Ino Y, 'Piezoelectric Transformer for Cold Cathode Fluorescent Lamp Inverter', JJAP Part 1-Regular Papers Short Notes & Review Papers, Vol.36, No.5B, 1997 https://doi.org/10.1143/JJAP.36.3050
  7. Y. Shimada, S. Kawashima, N. Furuhashi, M. Sugimoto, Y. Sato, H. Suzuki, and K. Isobe, 'LCD Backlight Inverter using Piezoelectric Transformer', NEC Technical Journal, Vol.48, No.10, pp.122-126, 1995