| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a direct current motor drive circuit that can control a wider range of the numbers of revolutions of motor in the case of controlling the number of revolutions of motor by allowing a power supply voltage to be variable. <P>SOLUTION: In a single-phase full-wave direct current motor drive circuit 10 that passes electric current through motor coils 21, 22 via a first arithmetic amplifier 15 that amplifies output signal of a hall element 11 and a second arithmetic amplifier 18 and a third arithmetic amplifier 24 that take the amplified output signal as an input, a reference voltage Vref output from a reference voltage output circuit 20 is supplied to each non-reverse input terminal of the second arithmetic amplifier 18 and the third arithmetic amplifier 24. <P>COPYRIGHT: (C)2008,JPO&INPIT |
