Failure monitoring circuit for doppler radar and sonar apparatus - uses evaluating circuit for comparison of actual and optimum vehicle, speeds, with failure light and control signal applying correction

摘要

The Doppler unit is used for the braking control of goods wagons and consists of an antenna connected to a transmitter/receiver whose receiving section has an evaluation circuit with digital filter connected to it. The Doppler oscillation at the output of the filter is fed to an amplitude detector whose output is then passed to a timing circuit feeding a warning light and conductor (7) carrying the failure signal which applies full braking should it be required. A pulse train proportional to the Doppler frequency is fed to a computer, which evaluates the true speed of the goods wagon, and compares it with the optimum speed which is based on the wagon weight, frictional losses, axle count etc. applying the brakes until both speed values coincide. If the Doppler signal disappears from the output (28) of the evaluating circuit, a signal is applied to the timing circuit, which in turn, applies the emergency braking control, and lights the warning lamp.