Elapsed-time counter for record player stylus - comprises probe assembly and galvanometer or mercury salt tube assembly operated by pick=up arm movement

摘要

The pick-up stylus on a record player for hifi records must be changed at specified intervals to maintain qualtiy. A counter activated from a probe enables the period of use to be recorded for the user. A probe (7) assembly is mounted on the record deck to sense movement of the pick up arm (3) onto the record. The probe arm (15) passes through the wall of its enclosure (6) such that a finger (14) is pulled by a spring (16) onto blades (10) of a switch assembly when the arm moves onto the record. The blades are isolated (12) and maintained in position by a screw (13) and are included in a galvanometer circuit or mercury salt tube assembly to record hours of use.