HIGH SPEED DETECTION APPARATUS OF DIGITAL INSTANTANEOUS LOW VOLTAGE

摘要

PURPOSE: A high speed detection apparatus of a digital instantaneous low voltage is provided to detect the instantaneous low voltage and compensate the low voltage state for the power converter by outputting the information in the form of digital value. CONSTITUTION: A high speed detection apparatus of a digital instantaneous low voltage includes a synchronization signal generator(10), a standard sign wave generator(20), a pair of wave rectifiers(32,34), a dividing circuit(40), an integrator(50), a comparator(60), a subtracter(70) and an analog-to-digital(A/D) converter(80). The synchronization signal generator(10) outputs the predetermined reset signal. The standard sign wave generator(20) generates a standard sign wave voltage based on the square wave voltage of the synchronization signal generator(10). The pair of wave rectifiers(32,34) rectify the standard sign wave voltage and the input power voltage. The dividing circuit(40) divides the standard sign wave voltage of the first wave rectifier(32) into the power voltage of the second wave rectifier(34). The integrator(50) integrates the output values from the dividing circuit(40) in response to the reset period. The comparator(60) compares the integrated value with the previously set reference value and outputs the instantaneous low voltage detection signal when the compared result is larger than the previously set reference value. The subtracter(70) calculates the difference between the standard sign wave voltage and the input voltage. And, the A/D converter(80) converts the difference voltage from the subtracter(70) into a digital value.