PURPOSE: To accurately know output characteristics of a DC power source by providing a peak holding circuit for a DC power source supplied with electric power from an AC power source, a voltage divider for the holding output, and a timer circuit, and measuring the time of a voltage rise up to a prescribed level by the timer.
CONSTITUTION: A computer 35 resets the peak holding 27 firstly and turns on a relay 22, and a DC output rises from the power source 23 by the AC power source 21. Voltage division 24 is carried out to hold 27 the peak value, and then the computer turns off the relay. The peak value is voltage-divided 28 and 29 to set an upper limit J' and a lower limit I' and then the computer clears a counter 32 and turns on the relay 22 again. When a DC output V reaches I, a comparator judges V'≥I' and a timer signal which is frequency- divided 34 is counted 32 through isolation 30 and an EXOR 31. Then, a comparator 25 judges V'≥J' and stops the counting operation, and the time of the rise of the DC voltage V from the level I to J is measured. Consequently, the accurate time of the rise corresponding to the actual output of a DC power source 23 is measured.
TAKAHASHI MASUMI
WAKO ELECTRIC