Abstract: An anti-siphoning device including a fill tube having a plurality of axially and radially spaced restriction elements extending across the interior thereof and an elastomeric annulus compressed between a pair of plates, one of which is mounted to the fill tube for securing the anti-siphoning device to the interior of a fill pipe. A plurality of apertures in the fill tube will allow rapid dispension of the fill liquid. A nozzle support retains an automatic fill nozzle above the restriction elements to prevent premature cut off.

Abstract: In association with a polyphase rectifying bridge having controlled rectifiers there is employed, in addition to the normal means for controlling the firing time of the controlled rectifiers, additional circuitry for preventing the occurrence of a commutation fault. This is achieved by first producing a timing signal representative of the time intervals during which a commutation between successively fired controlled rectifiers of the bridge actually exist. This timing signal, after being properly shaped is combined with a basic reference signal representative of a predetermined value to which the rectifiers may be phased back in their firing angle without resulting in a commutation failure. Stated in another way, the width of the existing commutation period serves to set a minimum to which the next commutation period must conform.

Abstract: In association with a polyphase hybrid rectifying bridge having controlled rectifiers, there is employed, in addition to the normal means for controlling the firing time of the controlled rectifiers, additional circuitry for preventing or at least reducing the probability of the occurrence of a commutation fault. This is achieved by first producing a timing signal which is representative of the time intervals during which a voltage exists across a load being supplied by the bridge and by then combining the timing signal with a basic reference signal representing a minimum time period during which this voltage should exist to guard against a commutation failure of the controlled rectifiers. When a prescribed relationship exists between the timing signal and the basic reference signal, the normal control means is overridden and the firing angle of the controlled rectifiers is advanced to a point which will guarantee commutation.

Abstract: An electronic filter circuit comprised of summing circuits and integrating circuits is interconnected such that the filter may use the same components to serve either as a band-reject or a band-pass filter having the same natural frequency. Changing of the filter operation between the two modes is accomplished simply by the interchange of two component values.

Abstract: In a power system, control signals derived from a measurement of dynamoelectric machine output voltage and current are selectively applied to an exciter to control the current in a field winding of the machine to control the machine reactive volt-amperes and output voltage.

Abstract: A generating system employing a generator having a self-excited field winding the excitation of which is achieved by supplying a bridge circuit with signals which are, respectively, proportional to the generator terminal voltage and the load current further includes means to selectively short-circuit the field winding during each cycle of normal generator operation. The system further includes a feedback path or loop for controlling the time during which the field winding is short-circuited which feedback path develops a control signal by comparing a signal representing the voltage supplied to the bridge circuit with a reference signal to develop an error signal which is then modified by a further signal proportional to the Thevenin equivalent voltage of the bridge circuit to thus linearize the feedback loop.