| 摘要 |
An analogue bipolar passive multiplier, especially for measuring of active or reactive electrical power (Fig. 10) comprises circuits for generating the voltage current product ui, ui.cos phi or ui.sin phi , wherein phi is the voltage, current phase angle, is based on the equation: (u+i)<2>-(u-i)<2>=4ui. The multiplier comprises a voltage divider consisting of first and second equal resistors (R1, R1) interconnected at a center point and connected across the voltage input or alternatively the current input (U resp. I) of the multiplier, and a third resistor (R2) having one end connected to the center point of the voltage divider and being connected across the current input or alternately the voltage input (I resp. U) of the multiplier. First and second half wave (Figs. 1, 2) or full wave (Figs. 3, 4) passive square function generators (PFG2), are connected respectively in parallel with the series connection of the first voltage divider resistor (R1) and the third resistor (R2), and with the series connection of the second voltage divider resistor (R1) and the third resistor (R2). The outputs of the function generators (PFG2) are connected to a parallel connection consisting of an output resistor (R4) and a filtering capacitor (C1) and of which the second end is connected to the other end of the third resistor (R2). For reactive power measurement, extra +/-45 DEG phase shifters are connected in the respective input circuits (Figs. 5-8). <IMAGE> |
