| 摘要 |
PURPOSE:To prevent damage to a load by stopping conduction to a load for a specified time or more when a malfunction occurs in a conduction signal due to an erroneous operation in a conduction controller. CONSTITUTION:The erroneous operation preventing device for an which outputs electronic apparatus comprises a time counter circuit G a conduction signal only for a conducting time, and a time monitor circuit F which inputs the signal output from the counter, counts the time at each inputting of the signal add outputs a power stop signal when it counts the time over a preset conduction allowable time. A three-terminal input NOR circuit 44 and a second AND circuit 54 for tuning OFF both a P-N-P transistor 32 and an N-P-N transistor 33 for controlling a conduction of a heat generating resistor of a printing head according to the stop signal output from the monitor F are provided. |
