Abstract: The invention is directed to a circuit arrangement and a suppressor-insulator member for suppressing noise in a portable hand-held electric-powered tool such as a double-insulated tool or the like while at the same time providing electrical insulation between voltage-carrying portion within the tool and an exposed part of the tool accessible to the operator of the tool. The suppressor-insulator member for conducting high-frequency noise from the voltage-carrying portion within the tool to the exposed metal part includes two connecting plates connectable to the voltage-carrying portion and the exposed-metal part respectively; and, a plate-like element of insulating material sandwiched between the connecting plates.
Abstract: Current leakage from high impedance signal circuits or networks of the type useful in the feedback paths of operational amplifiers is inhibited or prevented by circuit guarding. A lower impedance, parallel path provides a guard circuit that protects the signal circuit elements from excessive self-generated current leaks during closed loop use of operational amplifiers. The guard circuit includes equal potential nodes in the lower impedance path that are juxtaposed to corresponding nodes of the signal circuit elements. Current leakages, that may occur in the signal path, are mostly intercepted by the lower impedance guard circuit preventing the formation of electric fields or current leakage paths that would affect normal signal circuit performance.
Abstract: A mains safety isolating device is provided for an audio device e.g. guitar and microphone for preventing fatal electrical shock upon grounding breakdown and in which a transformer has a primary winding grounded at a point and connected to an electro-acoustic transducer to receive electrical signals therefrom, a secondary winding of said transformer is connected to a primary winding of a second transformer by signal conductors, a secondary winding of said second transformer being connected to the amplifier circuit of a mains powered amplifying and loudspeaker apparatus, said secondary winding being grounded at a second point separate and isolated from the first-mentioned point.
Abstract: Disclosure is made of a rectifier-inverter system of a converter substation intended for the transmission of energy between a.c. networks having different frequencies, which system comprises one or more pairs of rectifier and inverter converters connected to a common d.c. circuit.According to the invention, the poles of at least one rectifier or inverted converter are connected to a protective grounding via resistor-capacitor elements.The absence of direct contact with the ground in the d.c. circuit rules out the possibility of a low-resistance closed circuit being formed as a result of a short-circuit earthing at any point of the d.c. circuit. This reduces the voltage across the insulation with respect to the ground at each pole of all the converters and diminishes the steady voltage component across the insulation with respect to the ground of transformer valve windings.
Type:
Grant
Filed:
November 25, 1975
Date of Patent:
April 26, 1977
Inventors:
Viktor Ivanovich Emelyanov, Khaim Shlemovich Grois, Dmitry Evgenievich Kadomsky
Abstract: An electric receptacle with ground fault protection characterized by an insulating rectangular housing adapted for mounting in a wall outlet box. The housing comprises opposite end and edge walls with front and rear sides open and with a transverse partition dividing a chamber formed by the ends and side walls into a pair of side-by-side compartments. Partition aperture means between the compartments and the first compartment communicating with the open front side and the second compartment communicating with the open rear side. Receptacle components are disposed in the first compartment and electronic components are disposed in the second compartment, and the components in each compartment are so disposed as to minimize the space requirements for the receptacle.
Type:
Grant
Filed:
August 29, 1975
Date of Patent:
March 1, 1977
Assignee:
Westinghouse Electric Corporation
Inventors:
Gopal J. Virani, John J. Misencik, Roy O. Wiley
Abstract: An electrical receptacle assembly affording ground fault protection includes a housing containing fixed contacts supported by socket connector sub-assemblies. A support plate mounts an electronics/magnetics module and operating mechanism sub-assembly including a pivotal, movable contact carrying arm, a latch, a reset button and a trip solenoid. The reset button positions the latch to detain the arm with the contacts in circuit completing relation. On a ground fault, the module effectuates energization of the solenoid to unlatch the arm which moves to separate the contacts.
Type:
Grant
Filed:
October 22, 1975
Date of Patent:
March 1, 1977
Assignee:
General Electric Company
Inventors:
Keith W. Klein, Joseph M. Palmieri, George J. Lawrence