摘要 |
<p>An induction heating system includes a heating coil operable to inductively heat a load with a magnetic field, a variable high frequency power source supplying a high frequency current to the heating coil, a detector for detecting a current through the coil and providing a current signal representative of the current, a controller for controlling the frequency of the current to the heating coil and responsive to the current signal from the detector to capture and analyze a current signature, the controller being operative to sweep a current operating frequency across an operating frequency spectrum, and to combine a sum of the current signature with a two-sample swing of the current signature, and determine a presence of a load on the heating coil and control the frequency of the current to the coil based on a signal resulting from the combined signal.</p> |