OPTIMUM MODE SELECTING RESONANCE TYPE VIBRATING CLASSIFIER

摘要

PROBLEM TO BE SOLVED: To provide a vibrator of low cost and high performance in a powder vibrating classifier using attracting force of an electromagnet and restoring force of a continuous elastic body by selecting frequency of an optimum mode according to particle size from an intrinsic high harmonic group and accurately using a resonance phenomenon thereof. SOLUTION: This vibrating device is provided with: a means 16 for giving DC excitation to a search coil of an electromagnet 14 installed in a body to be vibrated to detect a vibration speed vector; a means 20 for calculating the product of the phase of the vibration speed vector and cosine waves of a two-phase oscillator for selectively oscillated near optimum vibration mode frequency and negatively feeding the obtained phase differential information back to a phase command to perform PLL control to make possible the correct high harmony resonance with high precision; and a means for giving, as a current command, the output of a PI arithmetic compensator 11 obtained by negatively feeding the absolute value of the vibration speed vector back to the speed command and giving, as a frequency command, sinusoidal waves of the two-phase subjected to PLL control to a current controlled type chopper 13 to control an electromagnet current.