Abstract: A method and apparatus for continuously monitoring the remaining ampere hours of charge of a rechargeable battery. The invention utilizes a voltage monitoring system actuated by a current monitoring system to measure battery terminal voltage only when current discharge attains a predetermined level. The value of terminal voltage measured is stored and applied to an indicating device to yield a constant readout of battery state of charge.

Abstract: An analyzer for an electrical vehicle control system which includes a self-contained power source to allow excitation and evaluation of individual components in the control system. The analyzer plugs into the control system and includes a plurality of switches for selectively connecting various output terminals of the analyzer to internal logic circuits for monitoring the operation of selected components of the control system on an individual basis.

Abstract: A control system for a DC electric traction motor which eliminates cogging of the motor during transition from a driving to a plugging mode. The system incorporates apparatus for comparing motor armature current to a plugging current reference voltage which voltage is initially applied as a ramp function to thereby provide a smooth transition into braking.

Abstract: A system for operating a bypass contactor in a time-ratio DC to DC control vehicle drive system. In order that the contactor be energized, it is necessary that the voltage across the motor exceed some minimum value, and that directional contactors be closed. A manual bypass switch and a speed control monitoring portion of the system are arranged in a logical OR configuration so that a third condition is fulfilled when either a mark-space ratio of the motor control system exceeds a predetermined value, or a fixed period of time elapses after manual closure of a bypass demand switch.In a further embodiment, operation of the bypass system is inhibited upon the sensing of either an undesirably low battery voltage or an inordinately large motor current.