Means for indicating the condition of lamps in a vehicle

Claim 1

FOR USE IN AUTOMOBILES, TRUCKS AND THE LIKE, VEHICLES HAVING A PLURALITY OF LAMPS ENERGIZED BY A POWER SOURCE THE IMPROVEMENT BEING MEANS FOR INDICATING THE CONDITION OF SUCH LAMPS AND BEING COMPRISED OF MAGNETIC MEANS; A PLURALITY OF FIRST WINDING WOUND ABOUT SAID MAGNETIC MEANS AND CONNECTED BETWEEN AN ASSOCIATED LAMP AND THE POWER SOURCE, SAID FIRST WINDINGS HAVING A FIRST MAGNETIC POLARITY; A BALANCE WINDING WOUND ABOUT SAID MAGNETIC MEANS BEING COUPLED TO SAID POWER SOURCE, SAID BALANCE WINDING HAVING A MAGNETIC POLARITY OPPOSING THE POLARITY OF SAID FIRST WINDINGS; THE RESULTANT MAGNETIC FIELD GENERATED BY ALL OF SAID WINDINGS BEING SUBSTANTIALLY ZERO WHEN SAID LAMPS ARE IN GOOD OPERATING CONDITION AND HAVING AN MAGNITUDE SUBSTANTIALLY DIFFERENT FROM ZERO ANY OF SAID LAMPS ARE DEFECTIVE;