| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a universal motor drive circuit that can be mounted even on small equipment while maintaining high power efficiency without giving an excessive load to a power supply by suppressing power loss. <P>SOLUTION: The universal motor drive circuit 100 is a drive circuit 100 of a universal motor 130 including a field winding 132, a rectification brush 134, a rotor having an armature winding, and a commutator 135. The drive circuit 100 is provided with a first current switch means 110, connected with the universal motor 130 in series, and a second current switch means 120, connected with the universal motor in parallel, so as to supply power from a commercial AC power supply 140 to the universal motor 130. The second current switch means 120 is configured so as to be conduction controlled according to the polarity of a voltage of the commercial AC power supply 140 and a conductive state of the first current switch means 110. The second current switch means is also configured so as to reverse the direction of a current flowing in the second current switch means 120 for each half cycle of the commercial AC power supply 140. <P>COPYRIGHT: (C)2009,JPO&INPIT |
