A Proportion-Air electronic pressure regulator is air piloting a J-relay valve which controls pressure going to the brakes on a locomotive. Controlling train brakes with electro-pneumatic valves from Proportion-Air brings extreme repeatability and excellent durability.

To apply brakes, pressure is proportionally vented from the dome of the J-valve by the Proportion-Air device.

This application shows the Proportion-Air electronic regulator being controlled by the locomotive’s computer. The computer receives its signal from a remote radio controller, which allows the operator to be located outside the locomotive where they can also move rail yard switches and connect rail cars to the train.

The Proportion-Air devices such as the QB1 or the QB3 are ideal for this application – they are not affected by shock and vibration up to 20Gs, do not require instrument air and they are very robust and reliable.

Learn how Proportion-Air products can also be used to control Train Throttle response as well.