INDUCTIVE LOAD DISCHARGE CURRENT RECIRCULATING CIRCUIT HAVING SELECTABLE QUICK MODE AND SLOW MODE

摘要

PURPOSE: To eliminate the need for a large area by using a single power device so as to alternately set a slow re-circulation or a fast re-circulation of a current thereby re-circulating a discharge current of an inductive load. CONSTITUTION: A transistor(TR) is kept to a saturated state with a current source supplying a sufficient current to a base of the re-circulation NPN TR to bring the TR to the saturation while a load desiring slow re-circulation of a discharge current is driven. The condition above is realized by a current oscillator I controlled by a switch S1 and the switch S1 is closed when the load is driven. When a fast re-circulation of a discharge current in an inductor L is desired, the switch S1 is open to cut application of the saturated current I to the base of the recirculation TR. Thus, the discharge current of the inductive load is re-circulated with a single power device. Thus, no large area is required.