Zellweger Luwa Ag

Zellweger Uster Ag

Petrus Warmerdam

The present invention relates to a measuring transformer which contains a primary conductor which carries current to be measured, and a secondary coil which is magnetically coupled thereto. The primary conductor is shaped helically and forms a body, like a helical spring, which surrounds the secondary coil with at least one turn. The primary conductor is preferably formed by a tube having a spiral groove which passes through its wall. The primary conductor has inherent stability which is very high such that no special holding means are required for the secondary coil. The secondary coil is extremely easy to install in the primary conductor and there are no problems with installation tolerances and the like.

Measuring transformer for solid-state electricity meters

A flat, modular measuring circuit having two connecting terminals for one phase of load current and a current sensor connected thereto. The two connecting terminals are arranged one above the other on one of the end faces of the module. This configuration leads to a significant reduction in the meter width and to a reduction in the production costs, since these modules can also be cost effectively produced in increased quantity and used for multi-phase meters.

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Wetzikon, Switzerland

Petrus Warmerdam