| 摘要 |
PURPOSE:To prevent faults such as breakage of a heater wire by supplying a power supply for logic circuit to a power supply line of the logic circuit through a diode for reverse current check and further, supplying a power supply for heater through a 3-terminal regulator and a diode. CONSTITUTION:A 5.8V power supply 11 is provided and a 5V output obtained by reducing a voltage by means of a diode for reverse current check 20 is fed to a power supply line 14 so that said output may be supplied to a driver circuit 1 and 'AND' gate 7. A 3-terminal regulator 21 having a 5.6V output is provided for the output of a 24V electrode for heater 12. After this, said output is caused to drop by approx. 0.8V through a diode for reverse current check 22 and then is supplied to the power supply line 14. If a main switch 10 is shut off, the 5V output of the power supply line 14 begins to drop. However, it is fed to the power supply line 14 from the regulator 21, thus maintaining the voltage at the same level for approx. 30msec. As a result, IC's of the AND gate 7 in the driver circuit 1 and a printing head 2 operate normally, preventing any faults such as breakage of heater wire. |
