| 摘要 |
PURPOSE:To reduce the cost by comparing a divided voltage generated between a winding and a resistor with a reference voltage, and setting the driving duty amount of a motor. CONSTITUTION:A comparator 18 compares a reference voltage to be supplied to a terminal of minus (-) side with a voltage to be supplied to a terminal of plus (+) side, and the compared result is output to a counter 19. The terminal of the - side is connected between two resistors R4 and R5, a reference voltage set by the resistors R4 and R5 is input, the terminal of the + side is connected to am intermediate point of the emitter ends of transistors Tr4, Tr5 and a current detecting resistor R1, and the divided voltage at the intermediate point is input. A microprocessor (CPU) 1 converts the count of the counter 19 into windings phi1-phi4 temperatures of a line feed motor 11 by the firmware of the CPU 1 and sets duty amounts corresponding to the temperatures. Thus, the temperature of a stepping motor can be controlled by 181 of comparators to reduce its cost. |
