Synchronous driving method for inductive load and synchronous controller for H-bridge circuit

摘要

In flowing a switching current through an inductive load by way of an H-bridge circuit, a control circuit and a timing signal generating circuit are used to start a current supply operation in accordance with a driving period of a predetermined frequency, thereby increasing the current flowing through the inductive load. In reducing the current, a power source regeneration operation is performed during a power source regeneration period and a commutation operation is performed during a commutation period. The power source regeneration operation and the commutation operation are well balanced with each other, thereby making it possible to perform a high-frequency driving with a switching current having less ripple. Also, since the power source regeneration operation is performed in a long time in the case where the switching current level is reduced, it becomes possible to quickly reduce the current level down to a desired level.