Patent attributes
A voltage detecting apparatus for detecting a voltage of a direct current power source by using a capacitor, which can process an abnormal voltage without elongation of measuring time. When a voltage between both terminals of the capacitor is greater than a maximum voltage in normal condition, a micro-computer discharges the capacitor through a third switch and a fourth switch to earth until the voltage between both terminals of the capacitor reduces to be not larger than a voltage corresponding to a maximum rated current of a reset switch. When the voltage between both terminals reaches to be not larger than the voltage corresponding to the maximum rated current, the capacitor is rapidly discharged through the reset switch by controlling the reset switch to be closed.
