Abstract: A motor brake control system for use on a motor having a motor brake retarder and a throttle fuel control is designed to respond to manual selection for sequentially retarding the selected cylinders in the motor. A transducer for sensing the speed of the motor is provided for generating a series of output pulses which access a high RPM detector and a low RPM detector. In the event that the motor exceeds a predetermined high RPM value, the brake control system activates all of the retarders to fully brake the motor. In the event that the brake retarders are on, either fully or partially, and the motor drops below a predetermined low RPM value, the brake retarders are released. Provision is made to prevent retardation of the motor as long as the throttle of the motor is being activated and retardation is further prevented after deactivation of the throttle until the fuel in the fuel delivery system has been consumed.

Abstract: A motor brake control system for use on a motor having a motor brake retarder and a throttle fuel control is designed to respond to manual selection for sequentially retarding the selected cylinders in the motor. A transducer for sensing the speed of the motor is provided for generating a series of output pulses which access a high RPM detector and a low RPM detector. In the event that the motor exceeds a predetermined high RPM value, the brake control system activates all of the retarders to fully brake the motor. In the event that the brake retarders are on, either fully or partially, and the motor drops below a predetermined low RPM value, the brake retarders are released. Provision is made to prevent retardation of the motor as long as the throttle of the motor is being activated and retardation is further provided after deactivation of the throttle until the fuel in the fuel delivery system has been consumed.