| 摘要 |
PURPOSE:To perform the speed control of motor without the use of tachometer generator by using Hall device for generating motor driving timing signal as speed detection device. CONSTITUTION:According to magnetic flux which varies with the rotation of rotor, an antiphase output voltage generates in the output terminals 56a and 56b of the Hall device 45. The comparator 57 compares the output to form a square wave of the deviation signal 57a which is in turn inversed at the circuit consisting of the resistors 58 and 59, the condenser 60, the transistor 61, and the resistor 62. The inversed signal is differentiated at the circuit consisting of the condenser 43 and the resistor 66 and then converted into a serration wave at the circuit consisting of the diode 67, the condenser 69, and the resistor 70. The serration wave output and the collector 61 output of the transistor 61 are combined compositely and then put in the comparator 73. At the comparator 73, the reference voltage 71a and the composite signal are compared, and according to the drviation, driving coil is operated by the output signal 73a as high level. |
