초록 ▼

A through-flow electric water heater has a cannister through which water to be heated flows and in which are disposed a first heating means comprising a plurality of electric heating elements and second heating means comprising at least one electric heating element. A control unit comprising a micro

A through-flow electric water heater has a cannister through which water to be heated flows and in which are disposed a first heating means comprising a plurality of electric heating elements and second heating means comprising at least one electric heating element. A control unit comprising a microprocessor receives a first input signal from a flow sensor and a temperature sensor which sense, respectively, the flow rate and temperature of the water flowing into the cannister and switches the plurality of heating elements of the first heating means on and off in different combination to achieve different heating levels and adjusts the level of heat dissipated by burst firing the at least one heating element of the second heating means to achieve a desired total heating level. A second temperature sensor is provided at the water outlet of the cannister to provide a second input to the control unit to adjust the total heat dissipated by the first and second heating means in response to the first and second inputs to maintain the temperature of the outflowing water constant. The heating elements are each switched on and off by its own solid state switching device (triac) mounted in thermal contact with the cannister to dissipate heat created by operation of the switching device to the water flowing through the cannister. A control panel enables the user to selectively adjust the water flow rate and the outflowing water temperature.

대표청구항 ▼

A water heater comprising a water inlet and a water outlet, passage means between said water inlet and outlet to permit a continuous flow of water from the inlet to the outlet, means to heat the water as it flows from the inlet to the outlet, the heating means comprising first electrical heating mea

A water heater comprising a water inlet and a water outlet, passage means between said water inlet and outlet to permit a continuous flow of water from the inlet to the outlet, means to heat the water as it flows from the inlet to the outlet, the heating means comprising first electrical heating means comprising a plurality of heating elements and second electrical heating means comprising at least one heating element, means being provided to switch each of said heating elements of the first electrical heating means on and off in different combinations in response to a control means to achieve different levels of heat dissipation to the flowing water by the first electrical heating means, means to burst fire said at least one heating element of the second electrical heating means to vary the heat dissipated to the flowing water by the second electrical heating means between maximum and minimum heating levels, the control means switching the at least one heating element of second electrical heating means on with at least some of the different combinations of heating elements of the first electrical heating means, and controlling the level of heat dissipation by the first and second electrical heating means to achieve a desired total level of heat dissipation.