To reduce power supply noises occurring in a control circuit unit for controlling an output buffer. A semiconductor device includes unit buffers for driving a data output terminal, impedance control circuits for controlling the unit buffers, and a control circuit unit for controlling the impedance control circuits. The impedance control circuits and the control circuit unit operate by mutually-different power supplies, the control circuit unit supplies pull-up data and pull-down data in mutually reverse phase to the impedance control circuits, and the impedance control circuits convert the pull-up data and the pull-down data from reverse phase to in-phase and supply the same to the unit buffers. Thereby, a noise is difficult to occur in a power supply VDD used for the control circuit unit.

An output buffer comprises a series connection of a first field effect transistor and a second field effect transistor, wherein the first field effect transistor is connected to a first supply potential terminal and the second field effect transistor is connected to a second supply potential terminal. An output terminal is connected to a common connection of the first transistor and the second transistor. The output buffer has a series connection of a resistive element and a capacitive element, wherein the capacitive element is connected to the output terminal, and a control circuit, to which an input signal is provided. The control circuit controls the transistors in such a way that turning off of a transistor is performed immediately, while turning on of a transistor is performed depending on the charging or discharging of the capacitive element, thus achieving a defined slew rate of the output signal at the output terminal.

A circuit includes a first power node at a first voltage level, a second power node at a second voltage level, a first voltage driver, a first current driver, and a control unit. The first voltage driver is configured to electrically couple a first output node to the first power node when a first input signal at the first input node is at a first logic state, and electrically couple a first output node to the second power node when the first input signal is at a second logic state. The first current driver is configured to inject or extract a first adjustment current into or out of a first output node. The control unit is configured to generate a measurement result of the first voltage level, and to set the first adjustment current according to the measurement result.

A semiconductor device including an integrator circuit, in which electric discharge from a capacitor can be reduced to shorten time required for charging the capacitor in the case where supply of power supply voltage is stopped and restarted, and a method for driving the semiconductor device are provided. One embodiment has a structure in which a transistor with small off-state current is electrically connected in series to a capacitor in an integrator circuit. Further, in one embodiment of the present invention, a transistor with small off-state current is electrically connected in series to a capacitor in an integrator circuit; the transistor is on in a period during which power supply voltage is supplied; and the transistor is off in a period during which supply of the power supply voltage is stopped.

A digital phase locked loop (DPLL), a method of operating the same, and a device including the same are provided. The DPLL includes a digitally-controlled oscillator configured to change a frequency and a phase of an output oscillation signal in response to a digital control code; a main divider configured to divide the frequency of the output oscillation signal and generate a first feedback signal based on the divided frequency; and a phase-to-digital converter configured to subdivide the phase of the output oscillation signal and to generate a quantized code by converting a phase difference between a reference signal and the first feedback signal using a phase-subdivided signal resulting from the subdivision. The digital control code is generated based on the quantized code.

Methods, systems, and apparatuses are described for compensating for an undesired fractional spur due to a PLL in a communication system. The communication system includes a time-to-digital converter (TDC) that is configured to execute in parallel to the PLL. The TDC is configured to determine a phase difference between a reference frequency and an output oscillation signal provided by the PLL. The phase difference is received by a processor to estimate particular characteristics of the undesired fractional spur, and the estimate of the characteristics is used to construct an estimate of the undesired fractional spur.

The present invention is directed to signal processing system and electrical circuits. More specifically, embodiments of the present invention provide a DLL system that provides phase correction by determining a system offset based on phase differences among the delay lines. The offset is used as a part of a feedback loop to provide phase corrections for the delay lines. There are other embodiments as well.

A system and method are disclosed to accomplish power savings in an electronic device, such as a memory chip, by performing selective frequency locking and subsequent instantaneous frequency switching in the DLL (delay locked loop) used for clock synchronization in the electronic device. By locking the DLL at a slow clock frequency, the operational frequency may be substantially instantaneously switched to an integer-multiplied frequency of the initial locking frequency without losing the DLL lock point. This DLL locking methodology allows for faster frequency changes from higher (during normal operation) to lower (during a power saving mode) clock frequencies without resorting to gradual frequency slewing to conserve power and maintain DLL locking. Hence, a large power reduction may be accomplished substantially instantaneously without adding complexity to the system clock generator. Because of the rules governing abstracts, this abstract should not be used in construing the claims.

Flip-flops in a monolithic three-dimensional (3D) integrated circuit (IC)(3DIC) and related method are disclosed. In one embodiment, a single clock source is provided for the 3DIC and distributed to elements within the 3DIC. Delay is provided to clock paths by selectively controllable flip-flops to help provide synchronous operation. In certain embodiments, 3D flip-flop are provided that include a master latch disposed in a first tier of a 3DIC. The master latch is configured to receive a flip-flop input and a clock input, the master latch configured to provide a master latch output. The 3D flip-flop also includes at least one slave latch disposed in at least one additional tier of the 3DIC, the at least one slave latch configured to provide a 3DIC flip-flop output. The 3D flip-flop also includes at least one monolithic intertier via (MIV) coupling the master latch output to an input of the slave latch.

A semiconductor storage device which stops and resumes the supply of power supply voltage without the necessity of saving and returning a data signal between a volatile storage device and a nonvolatile storage device is provided. In the nonvolatile semiconductor storage device, the volatile storage device and the nonvolatile storage device are provided without separation. Specifically, in the semiconductor storage device, data is held in a data holding portion connected to a transistor including a semiconductor layer containing an oxide semiconductor and a capacitor. The potential of the data held in the data holding portion is controlled by a data potential holding circuit and a data potential control circuit. The data potential holding circuit can output data without leaking electric charge, and the data potential control circuit can control the potential of the data held in the data holding portion without leaking electric charge by capacitive coupling through the capacitor.

A storage cell having a pulse generator and a storage element is proposed. The storage element input is connected to receive a data input signal. The storage element output is connected to provide a data output signal. The storage element is operable in one of a data retention state and a data transfer state in response to a storage control signal received from the pulse generator. The pulse generator is connected to receive a clock signal with rising and falling clock signal edges and is adapted to provide control pulses in the storage control signal. Each control pulse has a leading edge and a trailing edge. The control pulses have a polarity suited to invoke the data transfer state on their leading edges. The novel feature is that the pulse generator is adapted to initiate a rising-edge control pulse when receiving a rising clock signal edge and to initiate a falling-edge control pulse when receiving a falling clock signal edge. In this way, a dual-edge-triggered flip-flop may be made using only combinatorial logic circuitry and one level- or single-edge-triggered storage element. The storage cell has low power consumption, facilitates scan testing and can be used by existing design tools and test equipment.

A resonant clock distribution network architecture is proposed that enables a resonant clock network to track the impact of parameter variations on the insertion delay of a conventional clock distribution network, thus limiting clock skew between the two networks and yielding increased performance. Such a network is generally applicable to semiconductor devices with various clock frequencies, and high-performance and low-power clocking requirements such as microprocessors, ASICs, and SOCs.

A circuit includes a power supply terminal and a clock parsing circuit configured to produce multiple clock signals having a common clock period and different phases. The circuit further includes a plurality of digital circuits coupled to the clock parsing circuit and the power supply terminal. Each digital circuit includes an input to receive data and logic to process the data. Each digital circuit is responsive to a phase associated with a respective clock signal of the multiple clock signals to draw current from the regulated power supply terminal to process the data to produce a data output. Additionally, the circuit includes an output timing management circuit coupled to each of the plurality of digital circuits and configured to control data outputs of each of plurality of digital circuits to prevent timing violations at one or more destination circuits.

Two gate drivers each comprising a shift register and a demultiplexer including single conductivity type transistors are provided on left and right sides of a pixel portion. Gate lines are alternately connected to the left-side and right-side gate drivers in every M rows. The shift register includes k first unit circuits connected in cascade. The demultiplexer includes k second unit circuits to each of which a signal is input from the first unit circuit and to each of which M gate lines are connected. The second unit circuit selects one or more wirings which output an input signal from the first unit circuit among M gate lines, and outputs the signal from the first unit circuit to the selected wiring(s). Since gate signals can be output from an output of a one-stage shift register to the M gate lines, the width of the shift register can be narrowed.

A noise resistant switch control circuit is provided. The circuit includes a low pass filter configured to couple to a first terminal of a switch and a first voltage clamp coupled to the low pass filter. The first voltage clamp is configured to couple to a control terminal of the switch and limit a voltage of the control terminal relative to the first terminal to within a first clamping range. The circuit includes a second voltage clamp coupled to an input terminal of the switch control circuit. The second voltage clamp is configured to couple to the control terminal of the switch. The second voltage clamp is further configured to reduce a level of a control voltage coupled to the second voltage clamp. The circuit includes a bias device configured to couple to the control terminal of the switch and to impress a biasing voltage to the control terminal.

A semiconductor device prevents recognition failure in mutual recognition between a host and a device compliant with USB Specifications. The semiconductor device includes: an interterminal opening/closing section having a plurality of first conductivity type MOS transistors, the respective sources or drains of which are cascaded, in which the source or drain of a first-stage MOS transistor among the cascaded MOS transistors is used as a first terminal, the source or drain of a final-stage MOS transistor among the cascaded MOS transistors is used as a second terminal, and the respective gates of the cascaded MOS transistors receive a control signal for controlling the opening or short-circuiting between the first and second terminals; and a current bypass section that reduces a current flowing into either one connection node coupling the respective sources or drains of the cascaded MOS transistors.

A transistor being one of an IGBT and a MOSFET and arranged near a gate control circuit applies a gate control signal from the gate control circuit to the gate of a transistor arranged far from the gate control circuit. A gate control signal is applied via a resistive element to the transistor arranged near the gate control circuit.

An apparatus includes a biquad filter having first and second lossy integrators and multiple input networks. Each lossy integrator includes an amplifier, and each input network is coupled to an input of the amplifier in one of the lossy integrators. Each input network includes multiple resistors and a capacitor arranged in a T-structure. In a single-ended configuration, each input network includes a grounded capacitor. In a fully-differential configuration, each input network includes one of: a grounded capacitor and a floating capacitor coupled to another input network. The amplifiers and resistors could form a portion of an integrated circuit chip, which also includes multiple input/output pins. A single grounded capacitor could be coupled to a single input/output pin of the integrated circuit chip for an input network. A single floating capacitor could be coupled to two input/output pins of the integrated circuit chip for a pair of input networks.

Operation of a charge pump is controlled to optimize power conversion efficiency by using an adiabatic mode with some operating characteristics and a non-adiabatic mode with other characteristics. The control is implemented by controlling a configurable circuit at the output of the charge pump.

A power package is provided comprising a packaged transistor and a driving unit connected to the transistor and adapted to drive the transistor. A control terminal of the transistor is connected to a middle terminal pin of the housing of the transistor and outer terminal pins of the housing are connected to the driving unit and to a voltage level, respectively, wherein the connections are crossing free.

A phase locked loop (PLL) includes a first loop, a second loop, and a lock detector. The first loop locks a feedback signal having a frequency equal to a fraction of a frequency of an output signal to a reference signal in phase. The first loop has a first bandwidth. The second loop locks the feedback signal to the reference signal in frequency and has a second bandwidth. The first bandwidth is higher than the second bandwidth. The lock detector is coupled to the second loop and increases the second bandwidth in response to detecting that the feedback signal is not locked to the reference signal.

A method of controlling an integrated circuit chip including first and second clock sources, the first clock source being more thermally stable and having a higher power consumption, the integrated circuit chip being operable in a first mode in which the first clock source is inactive and the second clock source active and in a second mode in which the first and second clock sources are active, the method including operating the integrated circuit chip in the first mode; taking a measurement indicative of temperature; if the measurement indicates that the temperature is outside of a temperature band: activating the first clock source so as to operate the integrated circuit chip in the second mode; recalibrating the second clock source against the first clock source; and following the recalibration, deactivating the first clock source so as to return the integrated circuit chip to the first mode.

A power management device of a touchable control system includes a boost circuit, a storage circuit, a detection circuit and a loading circuit. The boost circuit has an output terminal and generates an output voltage. The storage circuit electrically connects to the output terminal of the boost circuit and stores the output voltage. The detection circuit electrically connects to the storage circuit so as to detect the output voltage. The loading circuit electrically connects or disconnects to the output terminal of the boost circuit according to a predetermined value of the output voltage.

An integrated circuit includes a circuit block to utilize a load current at a load voltage from a power input and two or more charge pump arrays. The outputs of the charge pump arrays are coupled to the power input of the circuit block. The integrated circuit includes one or more modifiable elements to disable one or more of the two or more charge pump arrays.

The present application discloses apparatus and methods for increasing channel utilization for a high-speed serial interface of an integrated circuit (IC). A new circuit architecture is disclosed which provides circuitry that may be programmed flexibly to support a multitude of different channel bonding schemes. In accordance with one aspect of the invention, the new architecture decouples the granularity of control-signal channel bonding from the granularity of data-aggregation channel bonding. This advantageously allows optimization of configurations for both types of channel bonding. In another aspect of the invention, the logical boundaries of bonded user channels are decoupled from the physical boundaries of the PCS modules. This decoupling advantageously eliminates a rigid constraint of previous architectures.

A semiconductor structure including a device configured to receive an input data-word. The device including a logic structure configured to generate an encrypted data-word by encrypting the input data-word through an encrypting operation. The device further including an eFuse storage device configured to store the encrypted data-word as eFuse data by blowing fuses in accordance with the encrypted data-word.

Methods, systems, and computer readable media for wideband frequency and bandwidth tunable filtering are disclosed. According to one aspect, the subject matter described herein includes a wideband frequency and bandwidth tunable filter that splits a filter input signal into first and second input signals, modifies the first input signal to produce a first output signal, modifies the second input signal to produce a second output signal having an intermediate frequency response, and combines the first and second output signals while adjusting their relative phases and/or amplitudes to produce a filter output signal with the target frequency response. Adjustment includes splitting the second input signal into third and fourth input signals, which are modified and then combined to produce the second output signal having the intermediate frequency response.

A semiconductor apparatus is provided herein for reducing power when transmitting data between a first device and a second device in the semiconductor apparatus. Additional circuitry is added to the semiconductor apparatus to create a communication system that decreases a number of state changes for each signal line of a data bus between the first device and the second device for all communications. The additional circuitry includes a decoder coupled to receive and convert a value from the first device for transmission over the data bus to an encoder that provides a recovered (i.e., re-encoded) version of the value to the second device. One or more multiplexers may also be included in the additional circuitry to support any number of devices.

In one example implementation, the present disclosure provides a direct current (DC) restoration circuit for restoring the DC component of a synchronization signal provided over an alternating current (AC) coupled link from a transmitting circuit to a receiving circuit. During a period of inactivity in the synchronization signal, the synchronization signal may experience a drift towards the common mode, and may affect the ability for the synchronization signal to properly trigger the receiving circuit. The DC restoration circuit is configured to hold the synchronization signal steady during the period of inactivity, and allow the AC component of the synchronization signal pass through to the receiving circuit during the period of activity to alleviate the problem of baseline drift in the synchronization signal.

Apparatus and methods for ultrasound transmit switching are provided. In certain implementations, a transmit switch includes a bias polarity control circuit, a bias circuit, a first high voltage field effect transistor (HVFET), and a second HVFET. The sources of the first and second HVFETs are connected to one another at a source node, the gates of the first and second HVFETs are connected to one another at a gate node, and the drains of the first and second HVFETs are connected to an input terminal and an output terminal, respectively. The bias circuit and the bias polarity control circuit are each electrically connected between the source node and the gate node. The bias polarity control circuit can turn on or off the HVFETs by controlling a polarity of a bias voltage across the bias circuit, such as by controlling a direction of current flow through the bias circuit.

This invention concerns a creepage control system for locomotives that optimizes adhesion while minimizing wasted energy, rail/wheel wear and shock loading on the drive train. The basis of the invention is to always maintain a small but positive value of the slope of the wheel-rail adhesion creep curve (or differential of adhesion versus creep) for all traction axles of the locomotive through microprocessor control. The value of the differential of adhesion versus creep is used to define an operating window for control and operation of motors continually in the optimum domain when high adhesion is demanded. When, due to a sudden increase in rail contamination, the value of the control function becomes negative, the microprocessor control reduces the generator excitation in stages until the function becomes positive and inside the operating window again. The microprocessor controls a rail cleaning system which is turned on or off depending on the cleanliness of the rail. It also controls a rail sanding system which is turned on or off depending on the magnitude of wheel creep.

A sand dispensing device designed to be carried in the trunk of a vehicle includes a housing having a partition forming two interior compartments. A supply of sand is stored in a first compartment and an electric air compressor is situated in a second compartment. A remote switch is operatively connected to a relay in the second compartment for energizing the compressor. An induction nozzle has a sand inlet extending through an aperture in the partition into the first compartment and is connected to an air supply tube connected to an output of the air compressor. An outlet tube in the second compartment has a first end connection to an outlet of the induction nozzle and a second end extending through a side wall of the housing. A pair of discharge tubes are connected by a quick release fitting to a second end of the outlet tube and a pair of discharge nozzles are provided on the discharge tubes for spraying a sand and air mixture adjacent drive wheels of the vehicle, to enhance traction on icy road surfaces. The device is conveniently removable from the vehicle trunk for replenishing the sand supply or for transferring between vehicles.

An apparatus for enhancing traction for two drive wheels of a self-propelled vehicle, wherein the kit includes a reservoir coupled to a primary conduit through selective actuation of a solenoid valve. The primary conduit is in fluid communication with a secondary conduit, wherein the secondary conduit includes a spray head positioned adjacent each drive wheel of the vehicle. The spray head includes an apertured semi-spherical spray head to disperse fluid to and adjacent the drive wheels to effect melting of snow and ice thereabout. The kit further includes a dispersion brush selectively securable about the nozzle to minimize dirt and debris intrusion into the spray head, and further includes elastomeric cap member to overlie the spray head and enclose the same during periods of non-use.

An apparatus including a container directing a sand mixture through a plurality of conduits, a conduit associated with each drive wheel of an automobile through an intermediate valve body operatively opened by a cable mechanism. The organization is typically mounted within an engine compartment of an automobile. Further, the organization utilizes a nozzle head mounted at a terminal end of each conduit adjacent each wheel, with each nozzle head utilizing an apertured dispersion plate, wherein each aperture is selectively closed to define a selective width of path of sand directed adjacent each drive wheel of the automobile.

A flexible tubular item having an outer flexible section of hollow tubing with a first end and a second end, a flexible wire positioned within the hollow tubing, a flexible paint layer covering an exterior surface of the flexible wire, and a viscous liquid contained within the hollow tubing. The hollow tubing is a transparent vinyl tube. The flexible wire is copper wire having a bend resistance greater than the bend resistance of the hollow tubing. The liquid is mineral oil filling the area around the flexible wire within the hollow tubing. Ball members are affixed in liquid-tight relationship within the first and second ends of the hollow tubing. These ball members are acrylic spheres having a diameter greater than the interior diameter of the hollow tubing.

This invention relates to a vehicle comprising an antihydroplaning system, particularly for improving the wheel adhesion despite the presence of a sheet of water on the road. Output signals from sensors for detecting body and chassis vibrations, ambient temperature and other parameters are analyzed to determine when hydroplaning is occurring or about to occur, and to activate antihydroplaning measures.

A standby sanding unit for emergency sanding of icy roadways has a plurality of sand hoppers that are connected to a tank holding air under pressure. The hoppers have hopper type bottoms that have nozzles attached to the bottoms so that when air under pressure is provided to the upper portions of the tank, sand will be discharged out through the nozzles. The air pressure tank has valves that control the flow of air under pressure to the hoppers, when needed.

A method, using pressure air, of delivering sand from a sand box in the trunk of a car to a traction site at the interface of a car drive wheel and an ice or snow covered road surface to achieve car movement therefrom, in which the pressure air, as admittedly also occurs in the prior art, delivers the sand from the sand box to the traction site, but also significantly supplements the gravity flow of the sand from the sand box so that the amount of delivered sand to the traction site is adequate for the purposes intended, thereby overcoming a significant shortcoming of pneumatic car traction devices.

A sand delivery system for use in automobiles, or other vehicles. The device uses the hollow front bumpers found on most modern vehicles today to store bags of sand, which is delivered through a number of nozzles located in the front of the vehicle. A blower system forces the sand through the nozzles and projects the sand in a wide pattern out in front of the vehicle. The system is designed to operate when the vehicle is braking. Because the sand is disbursed out in front of the vehicle, the tires can better utilize the sand for braking. Because the sand is projected out in front of the vehicle only a moderate amount of sand is needed to improve traction, thereby reducing the need for large quantities of sand. The sand delivery system can be tied to a manual switch, the vehicle's brake pedal, or to a computer that is tied into the anti-lock brake systems of a car. In the latter case, sand is only be applied when the anti-lock brake system is activated.

The doors of railroad passenger cars swing inward and toward the front of the car when opened for entry or exit by the passenger. An automatic locking device is described which may be mounted on the exterior surface of the door close to its trailing edge. When the railroad car is in motion, the pressure of the relative wind on an air foil acts to rotate the locking device to a position that prevents the door from opening. When the train slows and stops, the relative wind decreases and the locking mechanism returns to it's original position permitting the door to be opened.

The adhesion between a locomotive drive wheel and supporting rail can be substantially increased by application of a powder mixture that contains a hard particle constituent preferably including alumina, a soft particle constituent preferably including titania, and an iron oxide constituent. The mixture may be in the form of a dry powder, a paste with water or alcohol vehicle, or a metal composite that includes the powder.

An electrical short circuit protection device for an electric trailer brake controller includes a fuse connected between the controller and the trailer brakes and an acoustic piezoelectric transducer connected across the fuse. Upon a short circuit fault developing in the trailer brakes, the fuse opens and the transducer generates an audio warning signal.

An apparatus to improve traction conditions for motor vehicles under winter time driving conditions is disclosed. The invention comprises a sand storage reservoir and delivery system that supplies sand to each tire of a motor vehicle to aid in traction when driving in icy or snowy conditions found in wintertime driving. The sand reservoir provides sand to a plenum through four distinct sand compartments which dispense individual slugs of sand to a series of discs, connected via a cable, which move the sand through a delivery pipe to any of the four motor vehicle tires, as selected by application levers on the sand reservoir. The reservoir and associated controls are located inside the passenger compartment of the motor vehicle with the delivery tubes located on the undercarriage of the motor vehicle.

A method for supplying dry sand for spreading on road surfaces in freezing temperatures in a condition in which the sand remains fluid in freezing temperatures without the addition of salt includes the steps of drying the sand by providing a naturally occurring bed of the sand having an upper surface of the bed exposed to sunlight; planting on the upper surface a covering crop of a type such as alfalfa having deep roots which extend through the whole bed up to thirty feet deep in search of a water table below the bed and growing the crop for a period of time sufficient to allow the roots to penetrate the bed and to extract moisture from the bed to dry the sand in the bed. The dry sand is extracted from the bed and stored temporarily in a closed storage which prevents the re-introduction of moisture for subsequent use on road surfaces without the necessity of salt to keep the sand fluid for spreading.

A sensor detects force or other indications of an impending rollover of a motorized land vehicle. Upon detection of a threshold force value, the sensor actuates an applicator that delivers traction reducing fluid to the contact patch between at least one of the vehicle tires and the ground. The vehicle is enabled to dissipate the rollover inducing force by sliding laterally in preference to rolling over.

A vehicle-mounted device and method for delivering a traction enhancing material to a road surface directly in front of one or more tires is disclosed. The device delivers the traction enhancing material when an electronic controller detects a loss of traction. The device uses an air duct to collect air incident on the vehicle and direct the air to the road surface. The device further comprises a hopper to hold the traction enhancing material. The hopper is coupled to the air duct at an aperture. When activated, a valve assembly selectively opens and closes the aperture in response to controller commands. When opened, the traction enhancing material accelerates from the hopper into the duct and becomes entrained in the air stream where it is then delivered to the road surface. Once delivered, the traction enhancing material is introduced between the tires and the road surface to effectively increase the coefficient of friction therebetween.

An anti-hydroplane system for tires that includes a blower assembly in front of each of the tires of a vehicle. Each blower assembly discharges a high pressure stream into a water dispersal area in front of a respective one of the vehicle tires.

An apparatus (40,60) for aligning a rail conditioning system, such as a sanding system or a compressed air snow removal system of a locomotive. A source of light (50,70) is removeably and unmovingly attached to a conduit (44,62) of the rail conditioning system to direct a beam of light (53) toward a rail (46) to verify a location of impingement (56) of a spray of rail conditioning material (45,66). The source of light may be a battery operated laser pointer, and it may be attached to a fixture (48,72) that is removeably secured to the conduit. The fixture may be attached over an outlet nozzle (42,62) of the conduit, or it may be threaded onto the conduit in place of the nozzle when the nozzle is removed for cleaning and inspection.

If the wheel/rail adhesion for a railway vehicle is insufficient then the wheels may slip when braking. If slipping is detected, a control system may reduce the brake pressure to permit a controlled level of slip and so to optimize the braking force for the available adhesion. By determining the pressure supplied to the brake cylinder, a signal may be obtained which indicates the value of the adhesion. Alternatively the adhesion may be monitored by detecting any discrepancy between the braking deceleration demanded by the driver and the observed deceleration. The adhesion signal may activate a warning. It may also be used to adjust the rate at which sand is supplied by a sander to the wheel/rail interface. The rate at which sand is supplied may also be adjusted in accordance with other parameters such as the train speed.

A spreading device for confined application of grain type materials along a well-defined path on a road from a conveyor of a storing tank mounted on a moving vehicle includes a chute member mounted thereon that receives the materials from the conveyor and substantially drops them generally vertically under gravity on the road along the path in proximity and in front of a roller. The latter stops the materials relative to the road and confines, or packs, them on the road. The spreading device is adapted to be mounted on either side of the vehicle, in line with its wheels.