| 摘要 |
PURPOSE:To execute the control of the speed of revolution of a motor with accuracy two times as high as before by equipping it with a speed control means which controls a shifting means for getting new relative speed according to the cycle sought by a cycle detecting means. CONSTITUTION:An electronic typewriter is connected to a power source, and character keys and signal keys are operated with a key board KB, and a character printing control program, a driving control program for a DC motor 16, a driving control program for each motor 37-39, etc., are started. Thereupon, each motor 16 and 37-39 are driven and a printing mechanism is operated interlocking with time driving of the motor, and the characters or symbols inputted via the key board KB are printed. In this case, a controller C detects the cycle of the encoder signal corresponding to the speed of a DC motor 16, using the encoder signal inputted from a photointerrupter 36. And, it supplies a driving circuit 81 with a pulse signal at the duty ratio of PWM control so that it may be the set speed of revolution, and makes the motor 16 output a corresponding driving current. |
