| 摘要 |
A dot matrix printer and motor have hammers (24) forming in part a hammerbank (22) and a counterbalance (130) with a link to the position of the motor. The motor includes coils positively driven and then negatively driven after current in the coils has at least partially decayed. The current in the coils is allowed to decay further after negatively driving the coil. The motor coils are connected to an H bridge having transistors which can be formed in a full H bridge or half bridge. A controller switches the transistors to cause negative and positive flow through the H bridge for positive current flow from a reference level to an uper reference level, and a decay of current within the coils to an intermediate reference. The coils are then driven with a negative current from the intermediate reference level to a second intermediate reference level after which the current within the coil decays to a lower or initial reference level. <IMAGE> |
