| 摘要 |
PURPOSE:To obtain typing pressures corresponding to papers used as well as reduce the cost of power source by a method in which reference voltages for a voltage monitoring circuit are varied according to papers used and also a circuit to alter the exciting voltage of printing magnet is provided. CONSTITUTION:When using multi-ply papers, when a switch SW1 is opened, the exciting voltage Vo of printing magnet is raised by the voltage of a Zener diode Dz2 and the energy of a printing hammer is increased. On the other hand, when the voltage V2 becomes lower than a reference voltage V1, the output VLOW of a comparator CMP becomes 1, so that the voltage monitoring circuit stops the excitation of new magnet. When the switch SW2 is closed when a multi-ply paper is printed, however, a voltage at which the signalLOW is generated is varied from V1X(R2+R4)/R4 to V1X(R2+R4+R5)/(R4+R5) and load at high voltages is limited. |
