Abstract: A load tap changer includes a single mechanical switch that is movable to create, in a first position, a first conducting path between a first transformer tap and a load. When the switch is in a second position, the switch creates a second conducting path between a second transformer tap and the load. A first thyristor pair or other device creates a first alternate conducting path between the first transformer tap and the load when the switch is disengaged from the first position. A second thyristor pair or other device creates a second alternate conducting path between the second transformer tap and the load when the mechanical switch is disengaged from the second position. Each thyristor pair may be selectively triggered to provide a conducting path when voltage across either thyristor pair exceeds a predetermined level. A gate trigger circuit may be included for each thyristor pair, and a gate control circuit may control each of the gate trigger circuits.

Abstract: An adapter for use in friction stir welding is configured to be mountable in and rotated by a standard milling machine. In one embodiment, the adapter includes an upper housing, a lower housing, and a mounting element for transmitting rotational movement from the milling machine. At least a portion of the mounting element is mounted in the upper housing. The adapter may also include a tool holder connected to the lower housing and rotated by the mounting element; and a displacement mechanism for providing movement of the tool holder relative to the mounting element. The displacement mechanism may be isolated from the rotational movement of the mounting element and the tool holder. The displacement mechanism of the adapter may also include at least one piston cylinder assembly. In one embodiment, the upper housing and the lower housing form a part of the piston cylinder assembly.

Abstract: A ergonomic customizeable user/computer interface system for wireless computer control. A hand-attachable user interface device transmits control information upon activation of switches on the interface device. A base interface device receives the transmissions, decodes the information and provides control signals to the computer. The interface system allows for security authorization control and multiple computer or LAN operations with each user interface device. Greater functionality is provided by the use of personality modules in the user interface device for different modes of operation.