The manufacture of low voltage high current power supply using the MOT (Microwave Oven transformer) has been done. The purpose of this work is to convert low voltages into high currents by utilizing simple electrical equipment. This work use of varying voltages and different windings which are changed on the secondary winding section with a cable size of 240 mm 2, NYA cable type. The test is carried out with a series circuit, parallel circuit, and single circuit by utilizing a voltage of 30 V, 60 V, 90 V, 120 V and 5 different variations of winding. The results of this test provide knowledge of new methods that can be applied to iron smelting.