| 摘要 |
PURPOSE:To prevent a runaway and the like due to the state change of digital IC by resetting power source when a power voltage fluctuates by the hit of power source and noise. CONSTITUTION:A voltage comparison part 3 compares the voltages of a power source fluctuation detection part 1 and a reference voltage power source 2. When a voltage fluctuation is more than a prescribed value, the voltage comparison part 3 outputs a pulse and outputs the pulse of a specified width from a one shot multi vibrator 4. A constant current circuit part consisting of a series pass transistor 5, an excess current protection transistor 6 and a resistance 9 is reset by the output of the one shot multi vibrator 4, drops the base voltage of the series pass transistor 5 is terms of priority and resets a power circuit. Thus, the runaway of the computer due to the state change of digital IC can be prevented be cause power is reset after it is turned off for a specified time. |
