| 摘要 |
PURPOSE:To simplify a forward-backward switching mechanism, without reversing polarity of a power source line, by reversing polarity of a power source, alone, which supplies common contacts of coils of all phases with power. CONSTITUTION:At the time of forward turning, by connecting a switch S1 with minus side, a transistor Q5 is turned on to allow a common contact of coils L1 and L2 to be supplied with plus power supply voltage Vs, and at the same time, a control line (c) becomes high level and Tr Q1, Q3 and diodes D12, D13 are turned off. And therefore, Tr Q2 and Q4 are turned on and off at mutually adverse phases by an emitter output of a phototransistor Q10 to allow a motor to make forward turn. For backward turning, by connecting the switch S1 to plus side, Tr Q7 and Q6 are turned on and a common contact of coil L1 and L2 becomes minus power source level, and at the same time, the control line (c) becomes low level to allow Tr Q2, Q4 and diodes D11, D17 to be turned off. And therefore, Tr Q1 and Q3 are turned on and off at mutually adverse phase by a collector output of PTr Q10 to allow the motor to make backward turn. |
