| 摘要 |
PURPOSE:To enable simple detection of abnormality in the step motor and the drive circuit thereof by exciting the non-hold phase coil with the application of a slight energy to see if the drive transistor is turned ON or not. CONSTITUTION:As soon as the RESET signal goes to logic 1 at the closing of the power source, phi1 and phi2 drive signals move to logic 1 and phi1 and phi2 echo signals turn to 0 from among echo signals detected from the respective phase divider resistances 21 and 22. With the action of the monostable multivibrators 28-31 cascade-connected, the logic 1 is applied to the D flip flop 34 at the time of T1 and (T1+T2+T3), to detect abnormality. The abnormality detection at the time of (T1+T2+T3) is done when the phi3 and phi4 drive signals are turned to logic 1 during the short period of (T1+T2). The condition is found abnormal when the output invert OR gate moves to logic 1 with the development of the logic 0 output in the exclusive OR gate 23-26. |
