Patent ID: 6495809
Filing Date: 2002-12-17
Classification: H05B

Abstract:
An electrical heater comprising:a substrate; a plurality of electrical terminals, including a first electrical terminal, a second electrical terminal, a third electrical terminal and a fourth electrical terminal; first and second electrodes disposed on the substrate in spaced apart relation, each of the first and second electrodes having first and second power application ends, the first electrical terminal in electrical contact with the first power application end of the first electrode, the second electrical terminal in electrical contact with the second power application end of the first electrode, the third electrical terminal in electrical contact with the first power application end of the second electrode and the fourth electrical terminal in electrical contact with the second power application end of the second electrode; a first adjacent portion of the first and second electrodes having corresponding interdigitated electrode portions protruding therefrom, and another adjacent portion of the first and second electrodes devoid of interdigitated electrode portions; a thermistor material electrically interconnecting the first and second electrodes; and a voltage source connected to the first, second, third and fourth electrical terminals such that a summation of electrical paths between adjacent portions of the first and second electrodes is substantially the same from the first power application ends of the electrodes to the second power application ends of the electrodes.