| 摘要 |
<p>PURPOSE:To prevet a malfunction such as a runaway, etc. of a digital device by using a comparator to provide the hysteresis characteristics to the input threshold voltage for output of a reset signal. CONSTITUTION:An AC power supply is set at stabilized voltage V0 via a rectifying stack 1, a smoothing capacitor 2 and a DC stabilizing circuit 3 and supplied to a digital device 5. While a reset signal output RO is applied to a reset terminal of the device 5 from a reset signal generating circuit 30. This circuit 30 has a constitution as shown in the diagram, that is, the positive feedback is applied to a comparator 7 through a resistance 12. As a result, the output of the comparator 7 has the hysteresis characterstics. Then the threshold level set when a reset state of the signal RO is released is different from the threshold level set when the signal RO is changed to a reset state from a release state.</p> |
