| 摘要 |
PROBLEM TO BE SOLVED: To prevent a control circuit from being reset when a manual rotary knob is rotated in a printer equipped with the manual rotary knob for feeding a sheet. SOLUTION: The output from a rectifier circuit 110 outputting a high voltage is connected with the output from a rectifier circuit 109 outputting a low voltage by a voltage holding circuit 111 employing a Zener diode 113. When a manual rotary knob is rotated, an electromotive force is induced in a motor for driving sheet feed. When that voltage is large, it is detected by a voltage monitor circuit 115 and a switching circuit 104 is subjected to feedback control thus lowering the secondary voltage of secondary windings 107 and 108. A part of the output voltage from the rectifier circuit 110 is applied to the output of the rectifier circuit 109 through the Zener diode 113 and lowering of output voltage from the rectifier circuit 109 is suppressed. Consequently, lowering in supply voltage to a printer control circuit is suppressed through a three terminal regulator 114 thus preventing the control circuit from being reset. COPYRIGHT: (C)2006,JPO&NCIPI
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