V111N5B7@ubvms.BITNET (__Robby__) (09/25/90)
A little ways back I posed the question to the net as to what may cause spuratic, seemingrandom triggers of an armed alarm on a still day, the alarm being compmosed of two simple loops with only two contact switches and the rest vibration sensors. The responses were quite helpful in pinpointing the problem; it was suggested that resistance was accumulating in the circuit perhaps due to a staple through a wire or a bad switcleading to the eventual threshhold exceedance. Well, after two years with this problem, I narrowed the problem down to a defect inherant in the part! I don't have the catelog no. handy, but a phone conversation with Tandy's engineers in Texas confirmed that the silver mixture used in the contacts of the switch oxidize extremely rapidly. His solution was to either file the contacts every 3-5 months with emery cloth, spray them with a conducting oil (only a temporary solution) or wait till they come up with a replacement part for it (and we all know how long THAT can take) *sigh*. Isn't it comforting to know that defective parts that people rely on for safety and protection remain on the shelves going unnoticed by the consumer AND the dealers? (detect sarcasm) Does anyone know of any good manufactures of vibration-type switches?? Any help would be greatly appreciated.