| 摘要 |
To ensure completely automatic determination and indication of the current and voltage errors or, respectively, the phase displacement angles in three error range steps without using conversion factors, an adjustable error-compensated current transformer (T5) is provided, the secondary winding (WF) of which can be switched in decade steps. A reference voltage @ derived from a reference current transformer (T1) or reference voltage transformer excites a digital 90 DEG circuit and generates two squarewave voltages, one of which is in phase with the reference voltage @ and one of which is phase shifted by 90 DEG thereto. These squarewave voltages are used for driving two sequence hold amplifiers (S/H1, S/H2) which ensure that at the time of their application, the voltage error and the phase displacement angle are available as voltage value from the difference voltage @, which is also provided, and the reference voltage @, which are indicated on two mutually independent digital voltmeters (DV1, DV2) at a triggering rate of predetermined clock pulse sequence. <IMAGE>
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