Analog-to-digital voltage converter

Claim 1

APPARATUS FOR ESTABLISHING A COUNT CORRESPONDING TO THE MAGNITUDE OF AN UNKNOWN VALUE EXPRESSED BY AN ELECTRICAL POTENTIAL SUPPLIED BY AN INPUT COMPRISING, A STORAGE CAPACITOR CONNECTED TO THE INPUT FOR SAMPLING THE POTENTIAL THEREOF, MULTIVIBRATOR MEANS FOR PRODUCING AND TRANSMITTING A SERIES OF PULSES OF EQUAL AMPLITUDE FOR LOWERING THE SAMPLED POTENTIAL STORED BY SAID CAPACITOR THROUGH DISCHARGE OF INCREMENTAL CHARGES THEREFROM, MEANS FOR PRODUCING A START PULSE DISCONNECTING THE CAPACITOR FROM THE INPUT TO SAMPLE THE POTENTIAL OF THE INPUT AT ANY INSTANT, ZERO CHARGE DETECTING MEANS FOR PRODUCING A STOP PULSE IN RESPONSE TO DEPLETION OF THE SAMPLED POTENTIAL OF SAID CAPACITOR TO A VALUE LESS THAN ONE OF SAID INCREMENTAL CHARGES, IMPEDANCE CONVERTING MEANS CONNECTED TO SAID CAPACITOR FOR TRANSMITTING SAID PULSES FROM SAID MULTIVIBRATOR MEANS AFTER THE CAPACITOR HAS BEEN DISCONNECTED IN A CONDITION CHARGED AS SAID SAMPLED POTENTIAL A PULSE COUNTER, MEANS RESPONSIVE TO SAID START PULSE TO ENABLE THE MULTIVIBRATOR MEANS TO SIMULTANEOUSLY FEED PULSES TO THE CAPACITOR FOR DISCHARGE THEREOF AND TO THE PULSE COUNTER AND MEANS RESPONSIVE TO SAID STOP PULSE TO DISABLE SAID MULTIVIBRATOR MEANS WHEREBY THE COUNT ATTAINED BY SAID COUNTER DURING DISCHARGE FROM THE CAPACITOR WILL CORRESPOND TO THE SAMPLED POTENTIAL OF THE CAPACITOR PRIOR TO DISCHARGE THEREFROM.