Control of heating elements
AssigneeBreville Pty Limited
InventorsAshley Marsh-Croft, Tibor Hegedis, Brendan John Foxlee, Emma Craig, Lichan Meng
Life of this patent
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Abstract
An apparatus for controlling one or more switched high power loads (or heating elements). The apparatus including: one or more switched high power loads (or heating elements), each high power load being powered from a common alternating current power source, and wherein each load is independently switched using a switching signal for zero crossing switching to achieve a desired average power output; the switching signal is generated that comprises a repeated switching sequence; the switching sequence indicates a respective selecting activation for each of the switched high power load over a sequence of half or full cycles.
Claims21
A kitchen appliance comprising:
- a plurality of switched high power loads included in the kitchen appliance, each load being powered from a common alternating current power source;
- a processor apparatus included in the kitchen appliance comprising:
- (i) a memory having stored therein a lookup table;
- and
- (ii) a processor adapted to generate a plurality of switching signals for controlling the plurality of loads, wherein the plurality of switching signals are generated based on a respective switching sequence retrieved from the lookup table, wherein each switching sequence is indicative of selective activation of the plurality of loads over a sequence of half or full cycles of the common alternating current power source, wherein a combination of the plurality of switching signals has no frequency components less than 24 Hz or frequency components above 24 Hz have more energy than any frequency components below 24 Hz;
- and
- one or more zero crossing devices that are included in the kitchen appliance and that are electrically coupled with the plurality of loads and the processor apparatus, wherein the one or more zero crossing devices are configured to:
- (i) receive the plurality of switching signals from the processor apparatus;
- and
- (ii) independently switch each load using a respective switching signal of the plurality of switching signals for zero crossing switching to achieve a desired average power output.
A method of generating one or more switching signals that control operation of a plurality of switched high power loads in a kitchen appliance, each load being powered from a common alternating current power source, wherein the method comprises:
- generating, by a processor apparatus of the kitchen appliance, a plurality of switching signals for controlling the plurality of loads of the kitchen appliance, wherein the plurality of switching signals are generated based on a respective switching sequence retrieved from a lookup table stored in memory of the processor apparatus, wherein each switching sequence is indicative of a respective selective activation of the plurality of loads over a sequence of half or full cycles, wherein each switching sequence is indicative of a selective activation of the plurality of loads over a sequence of half or full cycles of the common alternating current power source, wherein a combination of the plurality of switching signals has no frequency components less than 24 Hz or frequency components above 24 Hz have more energy than any frequency components below 24 Hz;
- and
- receiving, from the processor apparatus by one or more zero crossing devices of the kitchen appliance in electrical communication with the plurality of loads, the plurality of switching signals;
- and
- independently switching, by the one or more zero crossing devices of the kitchen appliance, each load of the kitchen appliance using a respective switching signal of the plurality of switching signals for zero crossing switching to achieve a desired average power output.
Dependencies are inferred from the claim text.