| 摘要 |
PURPOSE:To prevent a mistaken printing due to the shortage of capacity by a method wherein the capacity of an electric source is set correctly by loading artificial loads before driving the printer. CONSTITUTION:A transistor TR1 is put ON by making a signal l outputted from an operation unit CPU into ''1'' to flow an electric current through the artificial loads DL1, DL2 and a waiting is effected during a time tw to stabilize the voltage of a printer driving battery B2. Then, if the voltage of both ends of the load DL1 is higher than a threshold voltage VBB between the base emitters of a transistor 2, the transistor TR2 is put ON and a signal wire (t) becomes the level of an electric source wire VSS for the unit CPU whereby it is judged that the voltage VB2 of the battery B2 is higher than the threshold voltage VTH and an electric current stronger than a threshold current ITH is being flowed, consequently, the transistor TR1 is put OFF to put OFF the loads DL1, DL2 and a printing signal P is outputted from the unit CPU to begin the printing by the printer PR. If the voltage of both ends of the load CPU is lower than the voltage VBB, the transistor TR2 is not put ON and the signal wire (t) is in the same level of the electric source VGG for the unit CPU as it is and the voltage VB2 is judged to be lower than the threshold voltage VTH, therefore, the transistor TR1 and the loads DL1, DL2 are put OFF and the printing will never be effected. |
