Signal conversion apparatus

Claim 1

A DEVICE FOR CONVERTING A DIGITALLY CODED INPUT TO AN ANALOG OUTPUT VOLTAGE COMPRISING A PLURALITY OF BISTABLE ELEMENTS, EACH OF SAID ELEMENTS CORRESPONDING TO A DIFFERENT BIT IN THE DIGITAL CODE TO BE CONVERTED, A CURRENT REGULATOR CONNECTED TO EACH BISTABLE ELEMENT FOR MAINTAINING A CONSTANT CURRENT THROUGH ITS ASSOCIATED ELEMENT, EACH OF SAID BISTABLE ELEMENTS HAVING CONNECTED THERETO A GASEOUS DISCHARGE DEVICE FOR VISUALLY INDICATING THE STABLE STATE IN WHICH THE ELEMENTS THEN RESIDES, MEANS FOR CAUSING EACH OF SAID BISTABLE ELEMENTS TO ASSUME ONE OR THE OTHER OF ITS TWO STABLE STATES IN ACORDANCE WITH THE BINARY VALUE OF ITS CORRESPONDING BIT, A RESISTIVE NETWORK, EACH OF SAID BISTABLE ELEMENTS CAUSING ITS CURRENT TO FLOW INTO SAID NETWORK ONLY WHEN IT IS IN ONE OF ITS TWO STABLE STATES, AND SAID BISTABLE ELEMENTS BEING CONNECTED TO DIFFERENT POINTS OF SAID NETWORK WHEREBY THE CURRENT FROM AND ELEMENT HAVING A BINARY SIGNIFICANT POSITION GREATER THAN THE LEAST SIGNIFICANT POSITION PRODUCES AN EFFECT UPON THE OUTPUT VOLTAGE DERIVED FROM SAID NETWORK TWICE GREATER THAN THE EFFECT CAUSED BY THE CURRENT FLOWING OUT OF NEXT PRECEDING ELEMENT OF LESSER BINARY SIGNIFICANCE.