| 摘要 |
PURPOSE:To prevent the breakage and deterioration of a driver and a motor, by preventing the simultaneous putting ON of phase A and phase A' or phase B and phase B'. CONSTITUTION:A phase A coil and a phase A' coil are excited by controlling the ON, OFF of transistors Tr3, Tr4 by phase A and phase A' switching signal. A phase B coil and a phase B' coil are excited by controlling the ON, OFF of the transistors Tr7, Tr8 by phase B and phase B' switching signal. When the phase A and phase A' switching signal is H level, the transistor Tr3 is put ON and the transistor Tr4 is put OFF while the transistor Tr3 is put OFF and the transistor Tr4 is put ON when the same signal is L level. Accordingly, the phase A will never be put ON simultaneously with the putting ON of the phase A'. The phase B will also never be put ON simultaneously with the putting ON of the phase B'. Accordingly, the phase A and the phase A' or the phase B and the phase B' will never be put ON simultaneously even when a micro-processor runs away in a system, in which the micro-processor is employed in a pattern generating circuit, therefore, the reliability of the system may be improved. |
