How It Works

Electronic Brake Systems

SensaBrake Antilock Brake System Electro/Air/Hydraulic Actuator

The SensaBRAKE people make available their Antilock Brake System for hydraulic braked trailers in the U.S.A.  There is no ABS requirement for these vehicles in the U.S. at this time.

The Electronic /Air/Hydraulic Actuator takes input from the incab brake controller as 0 to 12 volt input.

A two step process converts to a variable hydraulic pressure output . The input is fed to a microcontroller that applies proportional air pressure to a piston --this piston in turn applies force to the master cylinder. The master cylinder provides pressure to the brake that translates this pressure to mechanical brake force at the axle.

The ABS equipped trailer must include Tone Rings, Sensors and Sensor Mounting Blocks  at the wheel ends. These are normally supplied on the axle. We supply the ABS programmed Actuator.

Tone Rings or Exciter Rings are toothed and hub mounted for the Sensor to pickup wheel rotation. The Sensor is a coil and magnet assembly that generates signal to monitor the Tone Ring and its’s teeth as it passes. This is fed to the microcontroller for comparison. If the wheels lock up on brake application, the microcontroller sees a loss of signal from the sensor. This loss of signal then causes the microcontroller to release the applied pressure allowing the wheel to rotate again. The unit will continue to modulate up and down during the entire braking event. This action enables a fast and efficient deceleration. ABS is required in Europe and on the large Class 8 vehicles here in the United States.

 The SensaBrake contains an integral air compressor and reservoir. Because of the stored energy in the reservoir a battery is not needed for the breakaway function. Upon loss of power or breakaway the Sensabrake goes into emergency and applies the brakes at maximum. There is a blow down valve on the Actuator to allow brake release as required. They must hold for fifteen minutes but are not to be considered as park brakes.

The in cab controllers are explained here controller types
The non ABS SensaBrake is here Non ABS Sensabrake
The Pump Type System is different and is described here Pump Type Operation