Control circuit for direct current motor, has motor current branch, and free-wheeling diode interconnecting current branches such that diode is attached at contact point between motor and switching unit

摘要

The circuit (10) has a motor current branch (16), where a direct current motor (12) and a switching unit (14) are arranged in series connection in the branch. Another switching unit (20) and a capacitor (24) are arranged in series connection in another current branch (19). A free-wheeling diode (30) interconnects the branches such that the diode is attached at a contact point (26) between the motor and the unit (14). Another circuit (18) e.g. micro controller, closes the unit (20) durably after closing a third switching unit (46), when the capacitor reaches a minimum charging voltage.