| 摘要 |
PURPOSE:To obtain the accurate driver circuit of a stepping motor by installing a transistor circuit, a reference voltage generating circuit, a resistor, and a comparator which correspond to each phase coil and changing the preset voltage of said reference voltage generating circuit to two or more values with a second control signal. CONSTITUTION:A current supplied from a signal 13COM to a transistor(Tr) Q1 turns Tr's Q1 and Q2 on. In this time, a current supplied from a signal 1DR to a Tr Q3 turns the Tr Q3 on to pass a current through a resistor R3. When voltage is generated at both the sides of the resistor R3 and becomes higher than the reference voltage obtained by a reference voltage generating circuit 2, a comparator 1 turns the Tr Q1 off and the Tr Q2 is turned off to supply no current. A current flowing in a motor phase phi1 decreases, the voltage at both the sides of the resistor R3 becomes lower than the reference voltage obtained by the reference voltage generating circuit 2, and the Tr's Q1 and Q2 are turned on again. |
