System for demonstrating electrical science

Claim 1

IN A SYSTEM OF THE CHARACTER DESCRIBED, THE COMBINATION WHICH COMPRISES: (1) A BASE PANEL BEARING PLURAL SETS OF PERFOATIONS ARRANGED IN A PATTERN TO PROVIDE RECEPTION AND UNIQUE POSITIONAL SUPPORT FOR EACH OF A PLURALITY OF INDIVIVIDUALLY UNIQUE, NON-INTERCHANGEABLE DEMONSTRATION UNITS AS NAMED HEREINAFTER, (2) A BATTERY POWER UNIT MOUNTABLE IN ONE SET OF SUCH PERFORATIONS, SAID UNIT INCLUDING AN OUTPUT SDTRIP WITH TWO TERMINAL SOCKETS AND HAVING PLURAL AND DIFFERENT BATTERY HOLDING MEANS ARRANGED SO AS TO SUPPLY SELECTIVELY DIFFERENT VOLTAGES TO SAID TERMINAL SOCKETS, (3) A MAIN SWITCH UNIT MOUNTABLE IN ANOTHER SET OF SUCH PERFORATION, AND INCLUDING AN INPUT STRIP WITH A PAIR OF TERMINAL SOCKETS, AN OUTPUT STRIP WITH A PAIR OF TERMINAL SOCKETS, AND POLARITY REVERSING MEANS BETWEEN SAID RESPECTIVE PAIRS OF SOCKETS, (4) A MAIN EXPERIMENTAL UNIT MOUNTABLE IN STILL ANOTHER SET OF SUCH PERFORATIONS AND INCLUDING AN INPUT STRIP WITH A PAIR OF TERMINAL SOCKETS AND AN ELECTRICAL PHENOMENON DEMONSTRATION DEVICE, AND (5) PLURAL SETS OF RIGID CONNECTING BARS OR RESPECTIVE LENGTHS APPROPRIATE FOR CONNECTING RESPECTIVELY AND UNIQUELY THE POWER UNIT OUTPUT TO THE MAIN SWITCH INPUT AND THE MAIN SWITCH OUTPUT TO THE MAIN EXPERIMENTAL UNIT INPUT, THE ARRANGEMENT BEING SUCH THAT NO ALTERNATIVE CONNECTIONS CAN BE MADE INADVERTENTLY.