Dual feedback, high accuracy brake cylinder pressure control

摘要

A dual feedback, high accuracy pressure control means (10) for railcar braking systems having an electronic control module (14). A transducer (12) is electronically connected to the control module (14) for transmitting a pressure signal to the control module (14). There is a source of fluid pressure with such source of fluid pressure being at least one of a supply pressure and a regulated supply pressure. At least two solenoid valves have a fluid connection to one another and to the transducer (12) and are electronically connected to the control module (14) for receiving at least one of an apply and hold signal. At least two solenoid valves have a fluid connection to one another and to the transducer (12) and are electronically connected to the control module (14) for receiving at least one of a release and hold signal. A relay valve (26) has a fluid connection to at least two of the solenoid valves and to the transducer (12) and to such source of fluid pressure and to a braking device. At least two of said solenoid valves have a fluid connection to such source of fluid pressure. An exhaust to atmosphere having a fluid connection to at least two of the solenoid valves and to the relay valve (26) is provided. <IMAGE>