| 摘要 |
<p>PURPOSE:To automate excitation frequency adjustment in a vibratory carrier device that uses resonance frequency by fixing the effective value of the impressed alternating voltage of a vibration generating source, increasing and decreasing alternating voltage frequency to compute impressed electric power, comparing it with the last calculated value, and determining resonance frequency wherewith the impressed electric power is maximized. CONSTITUTION:A microcomputer 20 detects impressed voltage effective value by a PWM circuit 21, and performs sampling of the electric current value that flows into a vibration generating source 4 with a current transformer 22, a resistance 23, a rectifier 25, and an AID converter 26 to detect electric current effective value. After, impressed alternating voltage is fixed and the frequency of alternating voltage is increased or decreased, impressed electric power is computed from the effective values of the alternating voltage, the alternating current and the phase difference between both, and compares it with the stored last calculated value. Resonance frequency wherewith the impressed electric power is maximized is then determined from the result of the comparison. With this constitution, the adjustment of excitation frequency to the resonance frequency can be automated.</p> |
