PRINTER DRIVE CONTROL SYSTEM USING UNSTABLE POWER SUPPLY

PURPOSE:To stabilize an electric current and voltage which act on a special motor-driven actuator, by working a motor-driven actuator other than a specials motor-driven actuator in a state different from an original state in which the motor-driven actuator displays its original function when one or more special motor-driven actuators are worked. CONSTITUTION:In printing operation, a carriage-driving motor 13 a type wheel- driving motor 19, a printing hammer solenoid 21 and a ribbon feed motor 15 are actuated. In addition, during spacing operation, a motor 19 which is a motor- driven actuator other than a motor 13 is actuated in such a state that a type wheel 6 may not be allowed to rotate. That is, the motors 19, 13 are 4-phase stepping motors which are driven by means of 1-2 phase excitation and the motor 13 is supplied with a prearranged drive current for a prearranged time, while the motor 19 is continuously supplied with a drive current for a prearranged time through adjoining excitation phases A and B. In this case, the motor 19 does not rotate but consumes the power only, thus increasing a supply current from an unstable power supply 23 with no increase in an electric current flowing to the motor 13.