Abstract: Sensing methods and systems for transformers, and the construction thereof, are described herein. Example transformer systems and example methods for constructing a core for the system are disclosed. The example system includes a core with a bottom plate, two or more limbs mounted to the bottom plate and a top plate enclosing the core. At least one of the bottom plate, the limbs and the top plate is formed with a sensing component therein. The sensing component can be mounted to a spacer layer assembled within a stack of laminated layers. The sensing component can be mounted within a path defined within the spacer layer, for example. Methods for detecting operating conditions within the transformer are also disclosed.

Abstract: A method of proving safe operation of a complex electronic circuit, and apparatus for carrying out the method, in which a proving signal having known characteristics is superimposed on an input to the circuit and the output is searched for said characteristics. An example involves the use of a microprocessor arranged to evaluate a fast Fourier transform algorithm on the coded carrier signal of a railway automatic train protection system or of railway a.c. track circuit arrangement.

Abstract: To ensure the safe operation of an electronic circuit, for example an amplitude modulated carrier signal generator, an output of the circuit is analyzed to prove the presence of predetermined signal characteristics, for example the carrier signal, or a modulation frequency. The predetermined signal alternatively may be superimposed on an input to the electronic signal and proved subsequently to be present in the output. The output of the circuit is passed inhibited, according to whether or not the signal characteristics are proved present, by means of an output enable gate which is self-latching providing the output continues to be proved correct. A start-up circuit delays a possible inhibit for a limited period following initial power connection to the circuit in order that the output can become established.

Abstract: A railway track comprising a pair of rails is divided into a succession of segments, each segment having a railway track circuit for separating successive trains. The track circuit is switchable between an initial state and a complementary state and comprises a downstream impedance electrically connecting the rails at a downstream point, an upstream impedance electrically connecting the rails at an upstream point, an electromagnetic sensor located between the upstream and downstream impedances in the vicinity of one of the rails, a transmitting member, and a pair of receiving members. One receiving member is in electromagnetic communication with the electromagnetic sensor. The transmitting member and the other receiving member are switchable between connection to the downstream impedance and the upstream impedance.

Abstract: At the remote end of a Type C track circuit, the conventional diode and the winding of a power transfer relay connected in multiple are connected across the rails over a transfer relay front contact. This transfer relay and the track relay at the near end are normally energized by the same half cycle of track current from the alternating current (AC) source. If the AC source fails, a track battery is connected across the rails at the remote end in series with the diode and transfer relay multiple network over a transfer relay back contact. The diode is so poled that the track relay is energized from the track battery with the same polarity as the rectified alternating current and does not release during the transfer operation. The diode bypasses substantially all track battery current away from the transfer relay.

Abstract: Alternating current track circuit energy for train detection and cab signals is coupled to the exit end of an insulated, dual gage track section between the common rail and the other two rails connected in parallel. The track relay is connected at the entrance end in a similar manner. Impedance bonds for direct current propulsion are also connected between the common rail and the other two rails at each end. In all forms, the propulsion return current is sufficiently balanced between the three rails to eliminate cab signal interference in either gage. In a first arrangement, a direct wire connection multiples the two other rails at each end. Impedance bond taps to complete the return circuit provide a two to one turn ratio from the common rail end of the bond winding to equalize the propulsion current ampere turns on each side of the tap and thus balance the flux generated.

Abstract: A signaling circuit adapted to be used with railroad tracks or the like for ensuring fail-safe performance in respect to the operation of a control device, such as a track relay, which must function in a fail-safe manner, typically to become deenergized after a set period and to release or drop away when any emergency or failure occurs; thereby to produce a safe action, such as providing a warning signal to the engineer or operator of a train. The signaling circuit includes a quick-acting shunt detector which operates to detect short-duration shunting effects and functions to so extend or enhance them that they produce the desired result of releasing the track relay.

Abstract: A detective circuit for railway points composed of three track sections connected together at a junction or for a railway crossing composed of four track sections connected together at a junction.

Abstract: There is described a track circuit for use with a track section which may or may not include a switch. The system detects the presence of a railroad vehicle within the track section as it constitutes a shunt across the track. The track section is divided into a plurality of segments with each segment having a common boundary with at least one other segment. Alternating current signals are induced into each track segment and a sensor is provided for sensing and responding to the induced a.c. signals. A modulator is provided for intermittently affecting the sensed signal and a detector is provided for detecting and responding to the changing signal.The detected signals are gated through a logic circuit which provides first and second outputs indicating: the changes are as might be anticipated as a result of the modulation introduced; or, the changes are other than might be anticipated as a result of the modulation, respectively.