Abstract: Brake control systems and methods particularly suited for small trailers and the like wherein the angular velocity of each wheel in a selected pair of wheels is sensed and compared against each other to develop a control signal representing the differential in angular velocity between the respective paired wheels. In a skid control embodiment, while the brakes are being applied by the operator, the system automatically releases the brakes at both wheels in proportion to a velocity differential between the wheels indicating an impending skid. In the case of a trailer equipped with a sway control embodiment, the system automatically applies the brakes at both wheels in proportion to the wheel velocity differential representing excessive trailer sway. The respective skid control and sway control embodiments are useful alone or in a combined system.

Abstract: A trailer brake control system which includes a variable frequency oscillator, an electromagnetic inertial sensor adapted to detect either lateral acceleration or longitudinal deceleration of a trailer and to vary the output frequency of the oscillator in accordance therewith, and a circuit for applying trailer brakes as a function of such frequency variation either to correct a trailer sway condition indicated by lateral trailer acceleration or when tractor brakes have been applied as indicated by longitudinal deceleration of the tractor/trailer combination.

Abstract: A skid control system and method for use in conjunction with a vacuum-boosted hydraulic brake system of the type presently used in automotive passenger vehicles. The velocity of each monitored vehicle wheel is sensed and a signal indicative of wheel deceleration is derived. A skid control valve is connected to the vacuum booster of the brake system to vent the booster vacuum chamber to the atmosphere when an excessive wheel deceleration is detected at any one of the monitored wheels and thereby relieve brake pressure at all of the monitored wheels. When the wheel begins to speed back up to vehicle speed, the skid control valve is pulsed by a control signal having a predetermined frequency and having a duty cycle which increases a function of time over a predermined control period. In this manner, the brake pressure at the monitored wheels is gradually increased as a function of time until the brake pressure desired by the vehicle operator is again achieved.

Abstract: A brake control system comprising an electric brake or the like having first and second electrically-operated brake actuators adapted for separate actuation, an operator-responsive controller for applying a first braking signal to the first actuator, and a control circuit responsive to the first braking signal for applying a second braking signal to the second actuator in substantially linear proportion to the first braking signal when the first braking signal exceeds a preselected threshold.

Abstract: A card reader for reading data cards of the type having columns of machine-readable information thereon and transmitting data outputs representative of this information to an interface, includes a read station for sensing the information in each column and generating corresponding data outputs. A latching circuit receives data outputs from the sensing means and transmits the data outputs to the interface responsive to a strobing signal. A timing wheel is employed to detect the velocity of the cards during transport through the read station to provide an output proportional to velocity. A train of pulses is generated for each column responsive to the velocity output, and the period of the pulse train is adjusted to compensate for increases or decreases in the velocity of the card through the read station, by employing a phase-locked loop circuit.