Abstract: A variable frequency transformer including: a first parallel circuit including at least two of the rotary transformers arranged in parallel and having an isolating circuit breaker connected to a rotor winding of each of the rotary transformers, and a separate synchronizing circuit breaker connected to a stator winding in each of the rotary transformers in the first parallel circuit; a first main transformer having a first winding connectable to a first power grid and a secondary winding connectable to the isolating circuit breaker in the first parallel circuit; a second main transformer having a first winding connectable to a second power grid and a secondary winding connectable to each of the synchronizing circuit breakers in the first parallel circuit, and a control system operatively connected to each of the synchronizing circuit breakers, the isolating circuit breakers and the drive motors for each of the rotary transformers.

Abstract: A control device converts a torque instruction value of an AC motor into a current instruction of AC motor, and employs current control in which feedback is performed by PI control to match an actual current value with the current instruction. Further, the control device sets a target flow rate of cooling water flowing through a coolant passage based on the converted current instruction, produces a signal for driving a water pump to circulate the cooling water at the target flow rate thus set and provides the signal to the water pump. A revolution speed of the water pump is restricted according to a signal of the control device such that the cooling water circulates through the coolant passage at the flow rate matching with the target flow rate.

Abstract: The present invention is directed to a power control wiring device that includes an electronic switch circuit that energizes the electrical load in accordance with a timing regulation signal. A timing regulation circuit includes a primary timing regulation circuit and an auxiliary timing regulation circuit. The circuit is adjustable between a minimum power setting and a maximum power setting to thereby generate an adjustable primary timing regulation signal. The timing regulation circuit also generates an auxiliary timing regulation signal to thereby reduce power consumption. A primary manual power control mechanism is configured to adjust the primary timing regulation circuit between the minimum power setting and the maximum power setting. An auxiliary manual power control mechanism is configured to trim the maximum power setting in accordance with the selectable trim adjustment, the at least one auxiliary manual power control mechanism being user accessible.

Abstract: A power unit which makes it possible to reduce power transmitted from a prime mover to a driven part via an electrical path, to thereby increase the efficiency of driving the driven part. A first rotating machine of the power unit inputs and outputs energy between a stator and first and second rotors thereof, via magnetic circuits formed by generation of a rotating magnetic field, and the rotating magnetic field, and the rotors rotate while maintaining a linear relation in which respective differences in rotational speed between the rotating magnetic field and the second rotor, and between the second and first rotors are equal. The rotors are mechanically connected to a prime mover and a transmission, respectively. A second rotating machine of the power unit is mechanically connected to a drive part without via the transmission, and electrically connected to the stator.

Abstract: An architectural speaker assembly includes a speaker supported within the speaker enclosure of a mounting fixture. A grill is provided to conceal the speaker. A grill support is configured to support the grill substantially flush with a facing ring of the mounting fixture to blend into the surrounding ceiling or wall. The grill support includes a concave wall that surrounds the speaker. A number of bosses project form the wall, each boss supporting a permanent magnet that magnetically engages the grill to firmly hold it on the grill support.

Abstract: A partial discharge detection test link and system is disclosed to detect partial discharge of a power cable accessory. The power cable accessory includes a first accessory component and a second accessory component connected to each other. The partial discharge detection test link is a permanent or temporary substitute for a conventional service link, connects directly across the power cable accessory and includes a conductor member and a partial discharge sensor. The conductor member has an electrically conductive element and an insulation surrounding and extending along the electrically conductive element. The electrically conductive element is electrically connected directly between the first and second accessory components. The partial discharge sensor is disposed about the conductor member and has the electrically conductive element as a primary winding and a secondary winding with the insulation positioned between the primary and secondary windings.

Abstract: A preselector is omitted in a spectrum analyzer, for example, which is used to prevent an image signal from being inputted. In addition, an image signal of a signal which is located outside a range of set-up measured frequencies is suppressed as much as possible. For a range of set-up measured frequencies F1˜F2, and for each of a plurality of intermediate frequencies Fi, the frequency of the sweep signal is swept over a range F1+Fi˜F2+Fi to determine first measured data, and is also swept over a range F1?Fi˜F2?Fi to determine second measured data. The first and the second measured data are compared against each other for each measured frequency point, and if they are equal, the data value obtained or a data value having a minimum value unless they are not of an equal value is delivered to obtain measured data in which image data based on image signals has been suppressed.