Current restriction element responsive to applied voltage

摘要

PCT No. PCT/JP82/00047 Sec. 371 Date Sep. 20, 1982 Sec. 102(e) Date Sep. 20, 1982 PCT Filed Feb. 20, 1982 PCT Pub. No. WO83/03028 PCT Pub. Date Sep. 1, 1983.A current restriction device for alternate circuit with small size, low producing cost and low power loss has been found by using a ferro-electric body with rectangular hysterisis characteristics. Said device is used for instance as a ballast for restricting current in a fluorescent lamp. Said ferro-electric body has main component of BaTiO3, additive of Sr or Pb for substitution of part of Ba and Zn or Sn for substitution of part of Ti, and a mineralizer of Mno or Cr2O3. The voltage-current characteristics of said ferro-electric body show non-linearity that the impedance ratio (Z2/Z1) of the impedance Z2 measured with alternate field of 500 volts/mm to the impedance Z1 measured with alternate field of 5 volts/mm is less than 1/10.