ELECTRIC WATER HEATER.,申请号MX2000PA03813-传众专利搜索

ELECTRIC WATER HEATER.

申请公布号：MXPA00003813(A)

申请号：MX2000PA03813

申请日期：2000.04.18

申请公布日期：2002.05.23

申请人：

SHERWOOD-TEMPLETON COAL COMPANY,INC.

发明人：CARLISLE (NMI) THWEATT JR.

分类号：F24H9/20;G05D23/24;(IPC1-7):H05B1/02

主分类号：F24H9/20

摘要：An electric water heater is provided which includes a polymeric body having an elongated hollow and an inlet opening and an outlet opening in communication with the hollow for flowing water to pass therethrough. An electrical resistance heater having a heating element of a material exhibiting a positive temperature coefficient of resistance is disposed in the hollow of the polymeric body and in heat transfer communication with water flowing through the hollow. An electrical source supplies electrical power to the heating element to generate heat. A controller senses current flow through the heating element and determines a resistance related value, such as current or resistance of the heating element. The controller also determines a first derivative of the resistance related value over time, and determines a second derivative of the resistance related value over time, and controls power supply to the heating element as a function of the first and second derivatives and/or absolute re sistance.