| 摘要 |
Method and apparatus for monitoring wet contact touchpads where the opening of the contacts and the closing of the contacts of a wet contact touchpad are monitored and sensed by a timer/controller. The wet contact touchpad forms a capacitor which is charged to maintain a low voltage when the contacts are open. Upon reaching a predetermined decreasing voltage charge across the wet contact touchpad, the voltage status is further scrutinized by voltage sampling to determine when a contact closure or a contact break has occurred. Such determination is carried out in multiple cycle fashion by quickly and repeatedly introducing a charge voltage, discontinuing the charge voltage, and sampling the charged voltage to determine a decrease or an increase. A decrease indicates a wet contact touchpad closed circuit and an increase indicates a wet contact touchpad open circuit. Sampling of the increasing or decreasing charges determines timed occurrences accurately.
|
