Abstract: A system for monitoring and controlling an electrical distribution network comprises an electrical distribution substation having a local area network (LAN), a feeder subsystem and a gateway. The feeder subsystem is coupled to the substation and receives electrical energy therefrom for distribution to customers, and includes slave devices for performing switching functions. The gateway provides remote access to the slave devices and the LAN.

Abstract: A method for estimating phasors and tracking the frequency of a signal during frequency ramping is provided. The method uses a variable N-point DFT periodically to compute one or more phasors based on data acquired from one or more sampled signals. The period between DFT computations is a predetermined number of sample periods. After each DFT computation, the change in phasor angle between the current phasor estimate and the most previous phasor estimate is determined and used to estimate the instantaneous frequency of the signal. The current instantaneous frequency estimate and the most previous instantaneous frequency estimate are averaged to compute an average cycle frequency. In addition, a number of discrete frequencies and corresponding DFT windows based on a fixed sampling rate and a predetermined fundamental frequency of the signal are defined and used in estimating the instantaneous frequency.

Abstract: A new method of compensating for errors in phasor estimation due to oscillations caused by discrete fourier transforms used to estimate signal frequency is provided. The method uses a variable N-point DFT to compute one or more phasors based on data acquired from one or more sampled signals. At each sampling interval the change in phasor angle between the current sampling interval and the previous sampling interval is determined and used to estimate the instantaneous frequency of the signal. A non-oscillating phasor indicative of the instantaneous magnitude, angular frequency, and phase angle of the signal is generated based on the instantaneous frequency estimate. Instantaneous frequencies are averaged over a cycle of the signal to generate an average cycle frequency. In addition, a number of discrete frequencies and corresponding DFT windows based on a fixed sampling rate and a predetermined fundamental frequency of the signal are defined and used in estimating the instantaneous frequency.

Abstract: A brake apparatus is provided for tape recorders, particularly of the coaxial reel type, in which a single brake pad, mounted on a brake arm, engages a pair of adjacent coaxially disposed drive wheels for coaxial tape reels. The brake arm is biased by a spring into braking engagement with the drive wheels. A solenoid is operable to withdraw the brake arm, thereby disengaging the brake, when energized. The solenoid is controlled to be energized whenever a drive motor for the tape reels is powered, and to be deenergized when the drive motor is not powered. The disclosed structure provides automatic braking for the tape reels whenever the drive motor loses power or is shut off, thus providing positive mechanical braking both in a power loss condition and in a parking condition for the tape reels.

Abstract: To mimimize the weight of a magnetic tape recorder chassis and cabinet assembly, a wire frame chassis (18) carrying printed circuit board guides (20) and connectors (22) is mounted to one side of a sand cast bezel (24), and polyurethane wall panels (16) are secured to the wire frame. A cabinet cover and underlying tape transport assembly are hinged to the bezel to enable pivoting away from the wire frame, exposing circuit boards for servicing. The "open air flow" characteristic of the wire frame chassis (18) helps cool critical electrical components.

Abstract: A meter includes a single sweep hand dial for indicating maximum demand in a predetermined time period as well as a multidial decade register for recording cumulative demand. The sweep hand dial is driven by a pusher gear. A pusher arm urges the pusher gear in a first rotational direction to record maximum demand during the period. To reset the mechanism, a button is pushed manually to axially displace a reset gear into meshing engagement with a relatively high speed gear train driven by the timer motor. As the reset gear is thus moved, pins on the reset gear are displaced from stowage slots in a plate, and as the reset gear rotates, the pins ride on the plate until the reset gear completes a full cycle of operation during which time another pin on the reset gear engages a second tab on the pusher gear to reset the pusher gear in a rotational direction counter to that in which the pusher arm had rotated the pusher gear.

Abstract: A manual mechanism for resetting a rotatable member to its initial position is disclosed which provides for rotation of 360.degree. or more, rotates in one direction only, and can be simply locked and unlocked for periodic use. In one embodiment the resetting mechanism is applied to cumulative demand registers on watt hour meters.

Abstract: To minimize the weight of a magnetic tape recorder chassis and cabinet assembly, a wire frame chassis (18) carrying printed circuit board guides (20) and connectors (22) is mounted to one side of a sand cast bezel (24), and polyurethane wall panels (16) are secured to the wire frame. A cabinet cover and underlying tape transport assembly are hinged to the bezel to enable pivoting away from the wire frame, exposing circuit boards for servicing. The "open air flow" characteristic of the wire frame chassis (18) helps cool critical electrical components.