| 摘要 |
PROBLEM TO BE SOLVED: To prevent error due to phase difference and to easily regulate error by generating the output voltage of a shunt as regulated voltage synchronized with the voltage by a regulated voltage generating circuit. SOLUTION: Voltage corresponding to load current to which error regulated portion of output from an adder 90 is added and voltage output from a voltage divider 8 are multiplied by each other to obtain electric power, and converted to DC voltage in a proportion to the obtained power. Further, after this DC voltage is frequency-converted by a voltage/frequency conversion circuit 6, electric energy is obtained by a counter 7 to be a power pulse counting means. The adder 90 adds together a signal from a shunt 40, exciting current of a current transformer 41 to be problems in a light load area synchronized with the signal, and a signal of error regulated portion corresponding to minus error by offset of the multiplier 5, and hence error due to phase difference can be prevented. Further, because the error regulated portion can be optionally set by regulating current by a variable resister 83, error can be accurately regulated. |
