| 摘要 |
<p>LEVITATION HEATING USING SINGLE VARIABLE FREQUENCY POWER SUPPLY A system for magnetically levitating and inductively heating a workpiece. A single coil simultaneously levitates and heats the workpiece. A single variable frequency ac power supply in circuit with the coil supplies power for both levitation and heating to the coil. Means are provided for varying the frequency of the power supply output to vary the heating effect on the workpiece. Means are also provided in series with the coil for varying the apparent impedance of the coil as the frequency of the power supply output is varied to provide a constant current amplitude in the coil independent of the frequency to maintain a constant levitation force on the workpiece. Feedback and control means are provided for maintaining the amplitude of the power supplied to the coil at a constant value.</p> |
