초록 ▼

An electrically powered water heater includes a plurality of heating elements for substantially instantaneous heating of fluid passing through the heater. A controller for powering the plurality of heating elements is responsive to a temperature sensor in fluid communication with the heated fluid. T

An electrically powered water heater includes a plurality of heating elements for substantially instantaneous heating of fluid passing through the heater. A controller for powering the plurality of heating elements is responsive to a temperature sensor in fluid communication with the heated fluid. The temperature sensor activates each of the plurality of heating elements for a predetermined period of time that is preferably no more than 32 half cycles. The controller activates a second heating element after a delay of preferably no more than 8 half cycles after activating a first heating element. The predetermined period of time for activating each of the plurality of heating elements may be substantially equal, such that each heating element contributes substantially equally to the heating of fluid. In one embodiment, the heater housing is provided with a plurality of chambers, and a heating element is provided within each of the plurality of chambers.

대표청구항 ▼

[ What is claimed is:] [1.] An electrically powered heater powered by an alternating current source for substantially instantaneous heating of a fluid, the heater comprising:a housing defined at least one compartment therein having an inlet aperture and an outlet aperture;a plurality of electrically

[ What is claimed is:] [1.] An electrically powered heater powered by an alternating current source for substantially instantaneous heating of a fluid, the heater comprising:a housing defined at least one compartment therein having an inlet aperture and an outlet aperture;a plurality of electrically powered heating elements each within the at least one compartment for heating fluid;a temperature sensor in fluid communication with the heated fluid; anda controller for selectively activating each of the plurality of heating elements at a first zero crossing of alternating current and deactivating the activated heating element at a second zero crossing of alternating current in response to the temperature sensor, the controller activating a first of a plurality of heating elements for a predetermined first period of time equal to or greater than 1 half cycle and no greater than 32 half cycles of the alternating current source and activating a second of a plurality of heating elements for a predetermined second period of time equal to or greater than the 1 half cycle and no greater than 32 half cycles of the alternating current source, such that each of the first and second heating elements contributes substantially equally to the heating of the fluid passing through the heater.