Educational device

Claim 1

IN AN EDUCATIONAL DEVICE PROVIDING FOR INTERCHANGEABILITY OF MATCHED PAIRS OF QUESTION AND ANSWER PANELS, THE COMBINATION COMPRISING A CABINET INCLUDING A FACE PANEL HAVING A FIRST FRAME THEREON FOR REMOVABLY RECEIVING A QUESTION PANEL AND A SECOND FRAME FOR REMOVABLY RECEIVING AN ANSWER PANEL, A PLURALITY OF QUESTION CONTACTS ON THE FACE OF SAID QUESTION PANEL AND A PLURALITY OF ANSWER CONTACTS ON SAID FACE PANEL DISPOSED ADJACENT TO SAID ANSWER PANEL, CONDUCTOR MEANS FOR ELECTRICALLY CONNECTING ONE OF EACH OF SAID QUESTION CONTACTS TO A CORRESPONDING ANSWER CONTACT FORMING THEREWITH MATCHED PAIRS OF CONTACTS ON SAID QUESTION PANEL ELECTRICALLY CONNECTED TO SAID QUESTION CONTACTS BY CONDUCTORS DISPOSED BENEATH SAID FACE OF SAID QUESTION PANEL, SAID FIRST CONTACTS DISPOSED IN ELECTRICAL CONTACT WITH A CORRESPONDING SERIES OF SECOND CONTACTS ALONG SAID FIRST FRAME EACH OF WHICH IS ELECTRICALLY CONNECTED TO SAID ANSWER CONTACTS BY CONDUCTORS DISPOSED BENEATH THE FACE OF SAID FACE PANEL, ELECTRIC CIRCUIT MEANS IN SAID CABINET INCLUDING INDICATOR MEANS ON SAID FACE PANEL AND SWITCHING MEANS FOR ALTERNATIVELY ELECTRICALLY CONNECTING ONE TERMINAL OF SAID INDICATOR MEANS TO A SELF-CONTAINED POWER SUPPLY AND TO AN OUTPUT TERMINAL OF A STEP-DOWN TRANSFORMER IN SAID CABINET ADAPTED TO BE ELECTRICALLY CONNECTED TO AN OUTSIDE POWER SUPPLY, A PAIR OF PORTABLE PROBE MEMBERS ELECTRICALLY CONNECTED RESPECTIVELY TO THE OTHER TERMINAL OF SAID INDICATOR MEANS AND TO SAID POWER SUPPLY AND ADAPTED TO BE MANIPULATED AND DISPOSED IN ELECTRICAL CONTACT WITH EACH CONTACT OF ONE OF SAID MATCHED PAIRS OF CONTACTS FOR ENERGIZING SAID INDICATOR MEANS.