Sprecher + Schuh Ag

Sprecher & Schuh Ltd. (Ssa)

Viktor H Stephanides

Richard Thaler

Rudolf Graf

Ernst Lang

Hans-Rudolf Wuthrich

Hans Heutschi

Hans-Rudolf Wuethrich

A current transformer having at least one ring-shaped core with a secondary winding mounted thereon, and a primary conductor, located within its casing. An inner tube is provided between the ring-shaped core and the primary conductor, one end of the tube being electrically connected to the casing and its other parts electrically insulated therefrom. A cylindrical, electrically conductive screening shield at least partially overlaps the inner tube and is electrically connected to the casing on the side of the ring-shaped core which is distal from the electrical connection between the casing and the inner tube, while the other parts of the shield are electrically insulated from the casing. This overlap forms a short-circuit loop for any steep progressing wave which is generated when switching on a potential-free part of the circuitry, or when due to an interruption, a small capacitive current breaks off. The short-circuit loop thus prevents the generation of high inductive voltages at the secondary leads of the current transformer. The overlap also enables a steep progressing wave to progress without reflection and without capacitively influencing the potential of the secondary winding.

Current transformer with a ring-shaped core for use in a high voltage

A surge diverter connected between a conductor and ground comprising several spark-quenching gaps, voltage-controlled shunting resistors connected in series with these gaps and voltage controlled control-resistors, each connected in parallel either to a gap alone or to a unit formed by a gap and a shunting resistor in series with the latter. The voltage-controlled control-resistors have current-voltage characteristics with substantially the same steepness, while the resistance value of these control-resistors at the rated voltage increases sequentially from the conductor to grand.

Surge diverter

A puffer-type interrupter for a circuit breaker has a stationary piston received in a movable cylinder which is connected to the movable contact of the interrupter, and which also carries a nozzle for producing a blast of gas through the separating contacts of the interrupter when the cylinder is moved over the piston. An auxiliary piston is slidably mounted relative to the main piston, and mechanism is provided to connect the two pistons together when the interrupter contacts are closed, and to connect the auxiliary piston to the movable cylinder after the contacts have separated. The main pressure chamber within the cylinder and the fixed piston is connected to an auxiliary pressure chamber disposed between the main piston and the auxiliary piston in such a manner that, as the separating contacts reach an optimum separation for contact interruption, the pressure within the main cylinder can drop to a preselected value by pressure flow into the intermediate chamber between the main piston and auxiliary piston, thereby to control the force characteristic required for the operation of the interrupter.

Puffer interrupter with main and auxiliary pistons and common cylinder

A gas-blast switch possessing a fixed contact and a movable contact and a blast or discharge nozzle surrounding one of the contacts, the blast nozzle having its inlet connected with the outlet of a pump compartment for an extinguishing gas, this pump compartment can be pressurized by the switch cut-off or switching-off movement, and wherein the narrowest location or throat of the blast nozzle is arranged in the direction of blowing downstream with respect to the aforementioned one contact. The outlet of the pump compartment can be closed by a check or nonreturn valve which closes in the direction of the pump compartment. The inlet of the blast nozzle is connected via a gas chamber with the outlet of the pump compartment, the outlet of the gas chamber confronting the blast nozzle can be closed by means of a further check or nonreturn valve which closes in the direction of the gas chamber. In the inlet of the gas chamber which confronts the pump compartment there opens a throughpassage emanating from the inlet of the blast nozzle, this throughpassage possessing a third check or nonreturn valve which opens in the direction towards the aforementioned inlet of the gas chamber.

Growing community of inventors

Zu/ rich, Switzerland

Viktor H Stephanides