| 摘要 |
PURPOSE:To lower noise by applying a current of the same waveform as that of a current signal to a corresponding motor drive transistor, to which a current signal being formed in a current signal generation circuit, to eliminate a time difference at the time of switching respective phases. CONSTITUTION:Sensor signals HU<+>, HU<-> are supplied to the base of transistors Tr Q1, Q2 and the emitter of said transistor is earthed via constant-current source CS1 and the collector thereof is connected with a power supply Vcc via Tr Q3, Q50. Other V and W phases are also connected with Tr Q6, Q52, Q9, Q14 via Tr Q4-Q7 in like manner. Further, current mirrors CM1, CM2, CM10, CM11, CM12 are formed by respective Tr Q17, Q18; Q15, Q16; Q54, Q55, etc. U shape is controlled from the connection of the emitter of said power Tr Q16 and the collector of said power Tr Q18. Said V and W phases are also controlled in the same manner, though not shown. Thus, a current signal made by a current signal generation circuit is transmitted to a corresponding motor drive Tr to quick switching respective phases and to lower noise. |
