Abstract: A fluid filter monitoring system. A flow switch positioned in juxtaposition to a fluid flow path monitors fluid flow and provides an indication during those time periods when fluid is flowing at a rate exceeding a predetermined flow rate through the flow path. A monitoring circuit coupled to this indication provides various audible and/or visible indicators corresponding to detected conditions. The preferred design includes a timer for monitoring the time duration since the filter was installed as well as monitoring the time duration water or other fluids are flowing through the filter. Adjustably settable visible and/or audible indications are provided to indicate when the filter is reaching the end of its useful life as well as when this life period has been exceeded.

Abstract: A speech synthesizer control circuit for use in a vehicle. The circuit includes a number of features which provide cost effectiveness while maintaining speech synthesizer reliability. One feature of the invention is use of a counter circuit interposed between a control circuit and a memory where messages are stored. The counter is controllably clocked by the controller to create an address within the memory for a particular message. Other features of the invention include control of speech volume, chime generation, and voltage protocals in the speech synthesizer control circuit.