Abstract: A traction aid for providing traction to a wheel of a vehicle relative a ground surface has two sections, composed of side members and traction members, connected by a connecting mechanism enabling pivotal unfolding and folding of sections between folded and unfolded configurations for device. In unfolded configuration, sections are longitudinally opposed end-to-end to allow wheel to pass over both sections when device is deployed on ground surface. In folded configuration, sections are folded together and extend substantially parallel one another. Each section has a plurality of gripping members attached to side members and extending therefrom.

Abstract: A traction aid for providing traction to a wheel of a vehicle relative a ground surface has two sections, composed of side members and traction members, connected by a connecting means enabling pivotal unfolding and folding of sections between folded and unfolded configurations for device. In unfolded configuration, sections are longitudinally opposed end-to-end to allow wheel to pass over both sections when device is deployed on ground surface. In folded configuration, sections are folded together and extend substantially parallel one another. Each section has a plurality of gripping members attached to side members and extending therefrom.

Abstract: A method and a transmitter system is provided for modulating binary information on a frequency shift keying carrier in a very narrow band. Phase reversal keying is initially used to create a carrier. The transmitter of the present invention generates a carrier signal by modulating a reference signal and a control signal having two frequencies representing the binary data to be transmitted. The resulting phase reversal carrier signal is processed by high order filtering such that the output of the transmitter provides a frequency shift keyed carrier at very close frequencies. The resulting carrier signal may, at the receiver, be processed by very narrow band filtering so as to create a communication system which will use only a small part of the available spectrum.

Abstract: A power supply for an electronic device such as the control circuitry of a thermostat. The power supply has a current transformer with a primary winding in series with the power line that is connected to the heating source, and a secondary winding coupled to the primary winding through a saturable magnetic core. A thyristor connected across the output terminals of the secondary winding establishes a momentary short-circuit condition when the voltage developed across the secondary winding exceeds a preset level in order to prevent the magnet core of the transformer from saturating.

Abstract: The disclosure herein describes an apparatus for analyzing a physical quantity, such as current, and for providing an indication of this quantity to an actuating element, for example a relay; a value of the physical quantity is compared to two preadjusted reference points and, as a result of this comparison, the actuating element is either energized, de-energized or remains unchanged; the two reference points are entirely independent from one another and either one can be made greater than the other; a particular application for this invention is for actuating a current relay.

Abstract: The specification discloses an apparatus and a method for regulating the power factor in an electrical distributing-network line; according to one embodiment of the invention, the active line power is measured by means of a transducer, the output from which is a continuous voltage proportional to the active power supplied by the line; the reactive power of the line is then measured by means of a second transducer, the output from which is also a continuous voltage proportional to the reactive power supplied by the line; the voltage supplied by the active-power transducer is then divided by voltage dividers in order to obtain two reference voltages L.sub.1, L.sub.2, the values of which indicate the fixed limits for the line power factor; the voltage supplied by the reactive-power transducer is then compared with reference voltages L.sub.1, L.sub.

Abstract: The control system permits limiting the electrical demand of a distribution network to a desired maximum value by regulating the temperature of one or more thermal loads with heating or cooling elements; this system includes: means for measuring the instantaneous demand of the network; means for measuring the instantaneous temperature of each of the thermal loads; means for comparing the demand of the network to the desired maximum value; means for comparing the measured temperature to the desired temperature for each of the thermal loads; and means for disconnecting or for connecting in response to the information obtained by the comparison, a fraction of the elements which is proportional to the difference between the measured temperature and the desired temperature.

Abstract: A correction system for regulating the power factor of an electrical distribution network in which the phase difference between the potential V and the current I of a distribution line is measured. The voltage V and current I are detected, the phase difference between V and I measured, and the measured phase difference compared with first and second predetermined reference limits. When the measured phase difference is less than a first predetermined reference limit, capacitive loads may be added to the network, and when the phase difference exceeds a second reference limit greater than the first limit, the capacitive loads may be disconnected from the network. The actual demand is monitored and the capacitive loads connected only when the actual demand exceeds a predetermined demand value.