A Moisture Resistant Switch for Improving the Robustness of BTEs
By Knott, Bryan; Kochkin, Sergei, PhD; Hearing Review, Vol. 10, No. 12, pp. 44-45Publication Date: November 2003
Article discusses the development of the Deltek 2700, which is a two-pole triple-throw toggle switch designed for a behind-the-ear (BTE) hearing instrument. The Deltek 2700 was designed to combat switch failure, which can be brought upon by perspiration, and other contaminants, including dandruff and hair spray. Deltek evaluated different design solutions to prevent the exposure of the switch’s critical components to contaminants. Laboratory research demonstrated that sealing the switch element provided the greatest protection. The Deltek 2700 incorporates a completely sealed switch element made up of several layers, including a conductive layer and spacing layers completely sealed between polyimide layers. To incorporate the sealed switch, a pre-molded frame was developed that is soldered to the switch element. The frame is dimensionally identical to existing older technology and therefore is an easy, practical replacement. A sample of 40 Deltek 2700 switches and 43 switches with standard technology were subjected to accelerated environmental testing by Trace Laboratories, which is an independent testing laboratory. Each unit was subjected to uniform exposure to standard environmental factors by using a salt fog test, which is a reliable simulation of environmental factors that could potentially damage vital circuitry. The experiment demonstrated that sealed switch technology adds increased resistance to failure from moisture or contaminants than standard toggle switch technology.
Published by: Ascend Media LLC (Website:http://www.ascendmedia.com)
Link to text: http://www.hearingreview.com/Articles.ASP?articleid=H0311F06
