Audible or visual indicator for induction-heated hotplate

摘要

The indicators are part of an appliance which has a glass-ceramic top (2) on which a number of hotplates (1) are formed with underlying spiral induction coils (4) for production of an electromagnetic field to heat a ferromagnetic cooking vessel (3), and constituting a damping element in an oscillatory circuit excited from a mains frequency convertor (5). Three turns of wire (6), wound with a gap around each coil, are connected to a visual indicator (7) such as a light-emitting diode. Several such indicators are arranged around the outer edge of the appliance.