Abstract: An air dryer includes a first flow path through the air dryer and a second flow path through the air dryer in parallel with the first flow path. A diverter valve has a first position that provides fluid communication to the first flow path and a second position that provides fluid communication to the second flow path. A system parameter signal is reflective of fluid flow through the air dryer, and a controller receives the system parameter signal and produces a first control signal based on the system parameter signal. The first control signal controls the position of the diverter valve.

Abstract: An air dryer includes a first flow path through the air dryer and a second flow path through the air dryer in parallel with the first flow path. A diverter valve has a first position that provides fluid communication to the first flow path and a second position that provides fluid communication to the second flow path. A system parameter signal is reflective of fluid flow through the air dryer, and a controller receives the system parameter signal and produces a first control signal based on the system parameter signal. The first control signal controls the position of the diverter valve.

Abstract: A system for operating a locomotive parking brake includes a wheel brake, a coupling connected to the wheel brake, and means for applying force to the coupling. A sensor connected to the coupling measures a force applied to the coupling and generates a signal reflective of the force applied to the coupling. A method for operating a locomotive parking brake includes applying a force to a coupling connected to a wheel brake, measuring the force applied to the coupling, and comparing the force applied to the coupling to a first predetermined limit. The method further includes indicating that the force applied to the coupling is equal to or greater than the first predetermined limit.

Abstract: A digital pulsed phase locked loop (DPPLL) provides exact measurements of echo phase, time, and/or position delay as well as echo amplitude. These exact measurements provide better and more reliable results that directly benefit the many real world applications for the DPPLL. The DPPLL permits simultaneous tracking of multiple echo pulses and considerably improved echo selection and sampling.