Piezoelectric ballast apparatus

Claim 1

BALLAST APPARATUS FOR STARTING AND OPERATING A "RAPID START" FLOURESCENT LAMP FROM AN ALTERNATING CURRENT SUPPLY COMPRISING A FLUORESCENT LAMP HAVING HEATER FILAMENTS AT EACH END THEREOF, A PAIR OF PIEZOELECTRIC SHEETS EACH SHEET HAVING FIRST, SECOND AND THIRD SPACED ELECTRODES ON ONE SURFACE THEREOF AND FOURTH AND FIFTH ELECTRODES ON THE OPPOSITE SURFACE THEREOF, THE FIRST AND SECOND ELECTRODES BEING LOCATED OPPOSITE THE FOURTH ELECTRODE AND THE THIRD ELECTRODE BEING LOCATED OPPOSITE THE FIFTH ELECTRODE, EACH SHEET BEING OPPOSITELY POLARIZED IN THE THICKNESS DIRECTION, MEANS SECURING THE FOURTH AND FIFTH ELECTRODE SIDES OF THE SHEETS TOGETHER WITH THE ELECTRODES INSULATED FROM EACH OTHER TO FORCIBLY CONSTRAIN THE SHEETS FOR MOVEMENT TOGETHER, THE BODY FORMED BY THE JOINED SHEETS BEING MECHANICALLY RESONANT AT THE APPROXIMATE FREQUENCY OF THE ALTERNATING CURRENT SUPPLY, MEANS CONNECTING ONE OF THE LAMP HEATER FILAMENTS BETWEEN THIRD ELECTRODE OF EACH SHEET AND THE FIFTH ELECTRODE OF EACH SHEET, MEANS CONNECTING THE OTHER LAMP HEATER FILAMENT BETWEEN THE SECOND ELECTRODE OF EACH SHEET AND THE FOURTH ELECTRODE OF EACH SHEET, MEANS FOR CONNECTING THE FIRST AND FOURTH ELECTRODES OF EACH SHEET TO THE ALTERNATING CURRENT SUPPLY WHEREBY ON EACH ONE-HALF CYCLE OF APPLIED ALTERNATING CURRENT VOLTAGE, THE ELECTROSTATIC FIELD BETWEEN THE ELECTRODES CONNECTED TO THE ALTERNATING CURRENT SUPPLY IS IN THE SAME DIRECTION AS THE POLARIZATION OF ONE SHEET AND OPPOSITE TO THE DIRECTION OF THE POLARIZATION OF THE OTHER SHEET THEREBY TO BEND THE COMPOSITE BODY AND GENERATE THE LAMP IGNITION VOLTAGE BETWEEN THE THIRD AND FOURTH ELECTRODES AND THE LAMP PREHEAT CURRENT BETWEEN THE THIRD AND FIFTH AND BETWEEN THE SECOND AND FOURTH ELECTRODES RESPECTIVELY, THE LOAD CURRENT OF THE LAMP BEING LIMITED BY ALTERATION OF THE RESONANT FREQUENCY CHARACTERISTICS OF THE COMPOSITE BODY CAUSED BY BUILD-UP OF LAMP CURRENT AFTER IGNITION.