| 摘要 |
PURPOSE:To eliminate the wasteful power consumption of a pulse motor by providing a current varying unit for varying the current limiting value of a constant current. CONSTITUTION:A driver having power transistors Q1, Q2, Q3 supplies a current to the coils L1, L2 of a pulse motor. A current limiter having resistors R1-R3, a comparator 3 and an AND gate 1 limits currents flowing to the coils L1, L2. This limiting current is varied by a current varying unit having a resistor Ra and a buffer 2. The resistor Ra is connected with a point (a) at the resistors R2, R3, controlled by a computer signal from a microcomputer through the buffer 2 to set the resistor R3 and a resistor Rb in parallel to vary a reference voltage, thereby varying the limiting value of a current flowing to coils Ll, L2. |
