| 摘要 |
<p>A radio frequency heating device has a radio frequency generator (11) linked by a coaxial cable to a resonator unit (13) having antenna electrodes (16, 17) from which radio frequency energy is radiated when resonant conditions are established. The resonator unit (13) has no moving parts and resonance is achieved by varying the frequency of the output from the generator (11) by adjusting a variable component such as a grid circuit capacitor (27; 54, 57; 64) and observing the current drain on a power supply using an indicator instrument (20). The position of the variable component (27; 56, 57; 64) is controlled by a motor (55) driven by the output from a differential amplifier (30) the inputs to which are a demand signal from the control element (21) and a feedback signal from a component (20) mechanically linked to the variable component (27; 56, 57; 64).</p> |
