Thick film electrically resistive tracks
First Claim
1. A heating unit comprising an elongate thick film electrically resistive track of substantially constant width of between 1.2 and 2.1 millimeters along its length, to permit substantially even heat distribution over the length and width of the track, the length to width ratio being at least 10 to 1, the track being supported on a substrate of electrically insulative material, the track being configurated to achieve a predetermined heating profile.
1 Assignment
0 Petitions
Accused Products
Abstract
In a thick film water track, irrespective of track thickness or the material of which the track is constructed, the optimum track width is found to be in the range of from 1.2 mm to 2.1 mm. Further, for a given resistance, the track is longer and may be conformed to a pattern to give improved temperature distribution. Additionally disclosed is a heating element having a number of thick film electrically resistive tracks applied to the surface of an electrically insulative substrate and a switch for selectively connecting one or more of the tracks to a power supply. The resistance and hence the operating temperature of the heating element may be varied by changing the track or tracks connected to the switch.
80 Citations
20 Claims
- 1. A heating unit comprising an elongate thick film electrically resistive track of substantially constant width of between 1.2 and 2.1 millimeters along its length, to permit substantially even heat distribution over the length and width of the track, the length to width ratio being at least 10 to 1, the track being supported on a substrate of electrically insulative material, the track being configurated to achieve a predetermined heating profile.
Specification