7. A DEVICE FOR CONTROLLING THE AMOUNT OF ELECTRICAL ENERGY TRANSFERRED TO A LOAD THROUGH AN ELECTRIC CIRCUIT COMPRISING: (1) A SOURCE OF POWER (2) A LOAD, (3) AN ELECTRIC CIRCUIT FOR CONDUCTING CURRENT FROM SAID SOURCE TO SAID LOAD, (4) A HALL EFFECT CRYSTAL POSTIONED IN THE MAGNETIC FIELD PRODUCED BY SAID CURRENT AND HAVING A PAIR OF INPUT TERMINALS AND A PAIR OF OUTPUT TERMINALS, (5) MEANS SUPPLYING A CURRENT DIRECTLY PROPORTIONAL TO THE VOLTAGE ACROSS THE LOAD THROUGH SAID INPUT TERMINALS, (6) AN INDUCTOR HAVING A WINDING WOUND ON AN IRON CORE, (7) A MAGNETIC AMPLIFIER HAVING A SATURABLE CORE WITH A CONTROL COIL MEANS AND A MAIN COIL MEANS WOUND THEREON, (8) MEANS CONNECTING SAID INDUCTOR WINDING AND SAID CONTROL COIL MEANS IN SERIES EACH OTHER IN A CLOSED LOOP CIRCUIT ACROSS SAID PAIR OF OUTPUT TERMINALS, SAID INDUCTOR BEING OPERATIVE TO DELAY THE RISE IN CURRENT IN SAID LOOP CIRCUIT THAT OCCURS UPON THE APPEARANCE OF A VOLTAGE AT SAID OUTPUT TERMINALS, (9) MEANS FOR SUPPLYING A VOLTAGE ACROSS SAID MAIN COIL MEANS, AND (10) CONTROL MEANS OPERATIVE TO INTERRUPT THE CURRENT IN SAID ELECTRIC CIRCUIT IN RESPONSE TO THE CHANGE IN THE CURRENT IN SAID MAIN COIL MEANS THAT OCCURS WHEN THE CURRENT IN SAID LOOP INCREASED TO A VALUE CAUSING SATURATION OF SAID CORE.