Battery charger with output voltage automatically matching battery rating

Claim 1

IN A BATTERY CHARGER FOR CHARGING BATTERIES OF TWO DIFFERENT KNOWN VOLTAGE RATINGS AND BEING OPERATIVE TO AUTOMATICALLY PROVIDE CHARGING CURRENT OF THE PROPER MAGNITUDE FOR THE DIFFERENT BATTERIES, THE COMBINATION OF A TRANSFORMER HAVING A PRIMARY AND A SECONDARY WINDING; FIRST CIRCUIT MEANS FOR CONNECTING SAID PRIMARY WINDING TO AN A.C. SOURCE PROVIDING POTENTIAL OF A PREDETERMINED MAGNITUDE, SAID FIRST CIRCUIT MEANS AND SAID TRANSFORMER BEING OF LIMITED CURRENT CARRYING CAPACITY; THE TURNS RATIO BETWEEN SAID PRIMARY WINDING AND SAID SECONDARY WINDING BEING SUCH THAT A PRECISELY PREDETERMINED NO-LOAD DRIVING VOLTAGE APPEARS ACROSS SAID SECONDARY WINDING WHEN SAID PRIMARY WINDING IS ENERGIZED FROM THE A.C. SOURCE; RECTIFYING MEANS CONNECTED ACROSS SAID SECONDARY WINDING TO RECTIFY SAID DRIVING VOLTAGE; SECOND CIRCUIT MEANS FOR CONNECTING SAID RECTIFYING MEANS TO THE BATTERY BEING CHARGED TO PROVIDE A PATH FOR BATTERY CHARGING CURRENT; SAID DRIVING VOLTAGE BEING THAT PRECISELY PREDETERMINED POTENTIAL OPERATIVE TO PROVIDE A PREDETERMINED RATIO BETWEEN CHARGING CURRENT OF THE LOWER VOLTAGE RATING BATTERIES AND THE CHARGING CURRENT OF THE HIGHER VOLTAGE RATING BATTERIES; AND POSITIVE TEMPERATURE COEFFICIENT IMPEDANCE MEANS CONNECTED IN SERIES WITH SAID PRIMARY WINDING TO LIMIT CURRENT TO A VALUE WHICH CAN BE SUPPLIED VIA SAID FIRST CIRCUIT MEANS AND SAID TRANSFORMER, SAID IMPEDANCE BEING OPERATIVE TO PROVIDE A HIGHER RESISTANCE TO CURRENT FLOW WHEN CHARGING A BATTERY OF THE LOWER VOLTAGE RATING AND A LOWER RESISTANCE TO CURRENT FLOW WHEN CHARGING A BATTERY OF THE HIGHER VOLTAGE RATING.