| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a boosting circuit for a pre-drive circuit of a brushless DC single-phase motor having a small occupying space at a low cost. <P>SOLUTION: This boosting circuit for pre-drive circuit is equipped with four switching devices PF1 to PF4 for forming an H bridge circuit with a motor coil L1 therein, and drives the drive circuit of the brushless DC single-phase motor which requires a control voltage in excess of a power supply voltage while PF1 or PF2 is ON. Further, the circuit comprises two switching devices Q11, Q12 for boosting control, two capacitors C11, C12, and two diodes D12, D13, thus continuously outputting stable boosting voltage. <P>COPYRIGHT: (C)2004,JPO |
