| 摘要 |
<p>PURPOSE:To surely perform an eject operation by providing a power source voltage check circuit for comparing a voltage value of a power source with a prescribed first level and a prescribed second level lower than the first level and generating a discriminating signal. CONSTITUTION:In a power source battery 10, a power source voltage check circuit 33 for checking a power source voltage E is provided. One output A is inputted to an input terminal I1 of a CPU 11 and the other output B is inputted to an interruption terminal INT0 of the CPU 11, respectively. This power source voltage check circuit 33 connects three resistances 34-36 for dividing a voltage in series between a positive electrode terminal of the power source battery 10 and an earth and a voltage VA of a connecting point of the resistances 34 and 35 is connected to a non-inversion input terminal of a comparator 37 and a voltage VB of a connecting point of the resistances 35 and 36 is connected to a non-inversion input terminal of a comparator 38, respectively. A reference voltage VREF is connected to the non-inversion input terminals of the comparators 37, 38 and the output A is taken out from the comparator 37 and the output B is taken out from the comparator 38.</p> |
