Integrated system for using mains-independent electronic calculators - for application in classroom teaching uses multiple redundancy

摘要

A number of structural elements interact to ensure fault-free use and to forestall the risk of theft. A special form of housing for the individual electronic calculators is used which is larger than on standard pocket calculators and flatter than on standard desk calculators. Any two electronic calculators can be combined to form a cassette which appears automatically when the two sets are joined together with the keyboard inwards. The colour of the top of the housings contrasts with the colour of the bottom. A switching mechanism connects and disconnects the calculators and connects the built-in accumulators to the charger.