Patent · US Expired

Microprocessor controlled through-flow electric water heater

US4638147A · kind A · utility

87Cited by
3References
8Claims
0Family size

Inventors

Key dates

Filing dateOct 17, 1984
Grant dateJan 20, 1987
Priority date
Expiry dateOct 17, 2004

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF24H15/414
  • WIPO fieldThermal processes and apparatus
  • WIPO sectorMechanical engineering

Abstract

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 th…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.