| 摘要 |
The phasing of electricity meters (watt-hour meters) i.e., producing the proper phase relationship between its two interacting alternating magnetic fields, is performed by a punching operation after the meter is fully assembled. A lag plate in the form of a conductive loop which surrounds the central pole of the voltage magnet is provided with a tail into the base of which extends a slot opening from the opening of the loop. The slot can be extended outwardly from the loop by successive nibbles of a punch to increase the length of the current path around the loop. This increases the resistance and decreases the current and the lag effect. This slotted tail is now so positioned (and bent upwardly) as to be accessible from the top of the fully assembled meter, using a slim punching tool inserted downwardly through a narrow passage between the parts. The fully assembled meter is tested and the slot is then lengthened by an amount calculated from the test results, a second test and second calculated lengthening being expectable to achieve desired accuracy. The entire testing, inserting and lengthening operation can be computer-controlled.
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