Diminishing rate battery charger

Claim 1

IN A BATTERY CHARGER, THE COMBINATION OF A TRANSFORMER HAVING A PRIMARY WINDING CONNECTED TO A SOURCE OF A.C. POWER AND A CENTER TAPPED, STEP-DOWN, SECONDARY WINDING, A MAIN CIRCUIT HAVING SUCCESSIVELY THEREIN FROM SAID CENTER TAP, A CONTROLLED RECTIFIER INCLUDING A GATE, POSITIVE AND NEGATIVE BATTERY POSTS, AND A RETURN JUNCTION, SAID MAIN CIRCUIT ALSO INCLUDING AN AMMETER THEREIN, PARALLEL RETURN CIRCUITS, EACH INCLUDING A RETURN RECTIFIER TO RETURN SAID CHARGE CURRENT ALTERNATELY EACH CYCLE FROM SAID RETURN JUNCTION TO A RESPECTIVE SECONDARY WINDING EXTREMELY, A CURRENT LIMITING RESISTOR, A ZENER, AND A FIRST BATTERY CURRENT BLOCKING DIODE SUCCESSIVELY IN A SERIES CIRCUIT BETWEEN THE CENTER TAP AND SAID RETURN JUNCTION AND COOPERATIVE TO ESTABLISH A REFERENCE VOLTAGE, AND A GATE FIRING CIRCUIT CONNECTING SAID SERIES CIRCUIT, BETWEEN SAID ZENER AND SAID CURRENT LIMITING RESISTOR, TO SAID GATE, SAID GATE FIRING CIRCUIT INCLUDING A SECOND BATTERY CURRENT BLOCKING DIODE THEREIN FACING OPPOSITELY OF SAID FIRST BLOCKING DIODE, AND SAID GATE FIRING CIRCUIT DISPOSING SAID REFERENCE VOLTAGE FOR COMPARISON WITH THE ACTUAL BATTERY VOLTAGE IN OPPOSING POLARITY WHEREBY THE DIFFERENCE BETWEEN SAID VOLTAGES IS EMPLOYED TO GATE FIRE SAID CONTROLLED RECTIFIER FOR CHARGE CURRENT CONTROL WHEREBY THE DIMINISHING OF CHARGE CURRENT TO APPROXIMATE A MINIMUM IS INFORMATIVE AS TO WHEN A BATTERY UNDER CHARGE APPROACHES FULL CHARGE POTENTIAL.