PURPOSE: To display relatively accurately the difference of electric energy consumption between two operating devices to be compared in a short time by measuring the difference of electric energy consumption on a basis of the difference of current between branching circuits, which connect two devices to be compared to power sources, and voltages of devices to be compared.
CONSTITUTION: When plugs 7 and 8 of devices A and B to be compared are connected to receptacles 5 and 6, voltages of devices A and B are detected by a transformer 10 for measuring instrument, and currents are inputted to a differential amplifying circuit 17 through current transformers 11 and 12 and current-voltage converting circuits 15 and 16. The output of a multiplying circuit 18 is converted to pulses having a frequency proportional to the level by a bipolar frequency converting circuit 19 to flicker an indicator 26 through a frequency dividing circuit 23 and is counted in a counter 24 through a gate 20 and a frequency dividing circuit 22, and the difference of electric energy consumption between devices A and B to be compared is displayed on a display device 25. Meanwhile, a voltage comparing circuit 34 compares outputs of high-input impedance amplifying circuits 32 and 33 with each other, and a display device 37 is operated if the power consumption of the device A is larger, and a display device 38 is operated if the power consumption of the device B is larger.
YAMANISHI KAZUTAKA
NAKAZATO ISAMU
SATOU TOSHIYA
KAWABATA HARUYUKI
SAITOU KAZUYUKI
SUZUKI TOSHIYUKI
KANEKO MASAHIRO
SAKAI MASAMICHI
KASAI KIHACHI
FURUYA AKIRA
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