Siemens Aktiengesellschaft

Peter Bradt

Gunter Prietzel

A compact high-voltage transformer resistant to moisture leaching and acids for airport navigation light systems includes primary and secondary windings wound upon a plastic coil form in turn surrounding a central portion of an iron transformer core. Connector socket members retained with prefixation on the coil form are provided with connector sleeves for receiving external leads, the sleeves being conductively connected to the ends of the primary and secondary windings. The transformer core is spaced from the inner surface of the coil form by means of spacer elements molded onto the inner surface of the coil form whereby a layer of thermoplastic synthetic resin material is injected between the core and the coil form during an injection molding operation. The injection molded jacket is the only insulation jacket provided in the transformer assembly.

Transformer with cast insulation jacket

A current transformer comprises coil forms mounted on two opposite legs of a rectangular iron core, and insulating parts for insulating the iron core from a current bar which can be brought through the interior of the current transformer. The coil forms are connected together at both ends by an insulating part which surrounds at least partially the exposed legs of the iron core in U-fashion. For manufacturing a current transformer, the coil forms are first connected by assembling the insulating parts to the coil forms to form a frame into which L-shaped laminations are inserted to form the iron core. These laminations are connected at the abutting gaps by a welded seam. The current transformer is suitable particularly for use in low-voltage circuit breakers.

Current transformer having a rectangular iron core

This invention concerns a coil form with integral comb-like fins at least on one end, between which contact elements are placed that can be connected with the winding ends of the windings. Each contact element is held by the fastening grooves of two adjacent fins. In order that all connecting points can be made in the same, universal fashion, independent of the wire diameter of the individual winding leads, the contact elements are provided with a 'U'-shaped receiving channel running parallel to the coil form axis. This receiving channel can be closed by a cover and can be ultrasonic welding to the walls of the receiving channel and to the winding ends inserted therein.

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Ganderkesee, Germany

Peter Bradt