Patent ID: 6704497
Filing Date: 2004-03-09
Classification: A61F,H05B

Abstract:
An electrical heating device for heating an object to a required temperature, the heating device being configured to supply a predefined heating power W to said object and comprising a heating element having a substantially rectangular cross section so as to define at least one major outer surface through which heat is dissipated, and a power source for supplying voltage U to the heating element, wherein:the voltage U supplied to the heating element and physical parameters of the heating element comprising a specific resistivity &rgr;, length l, width b and thickness &dgr; are selected so as to satisfy the following relations, at a given power supplied to the heating element which is substantially equal to said predefined power W: b&GreaterEqual;k&CenterDot;I&CenterDot;Ï Î´l&GreaterEqual;k&CenterDot;U&CenterDot;Î´Ï wherein I is the electric current passing through the heating element at the given power W and the selected voltage U; &rgr; is the specific resistivity (OhmÂ·mm2/m); &dgr; is the thickness of the heating element in millimeters; k is a correction coefficient providing the units of length and width in meters and millimeters, respectively, and selected such that increase in the value of k results in increase in the surface area of the heating element and decrease in the surface temperature of the heating element; the heating device thereby providing a desired temperature gradient between the temperature of said at least one major surface of the heating element and said required temperature.