| 摘要 |
PURPOSE:To remarkably reduce the power consumption of a stepping motor drive circuit by supplying analog signals to drive means after converting the signals into switching signals modulated in pulse width in accordance with the levels of the analog signals. CONSTITUTION:Analog signals VDA-VDD which change stepwise are respectively generated by means of logic circuits 21-24 and A/D converters 31-34. Comparators 51-54 supplied with triangular waves VT respectively generate switching signals VCA-VCD modulated in pulse width in accordance with the levels of the signals VDA-VDD and amplifier circuits 41-44 supplied with the signals VCA-VCD can perform switching operations. Therefore, the power consumption of circuits in the output stages of the circuits 41-44 can be remarkably reduced, because the circuits perform saturated switching operations. |
