tvåkretssystem

A tvåkretssystem, often translated as a two-circuit system or twin-circuit system, is a type of brake system design found in many vehicles, particularly in older or simpler automotive designs. The fundamental principle behind a tvåkretssystem is redundancy. It divides the braking system into two independent circuits. If one circuit fails, the other can still provide some braking power, albeit usually reduced.

Typically, a tvåkretssystem operates by splitting the braking effort between the front and rear wheels, or diagonally between the wheels. For example, one circuit might operate the front-left and rear-right brakes, while the second circuit operates the front-right and rear-left brakes. In another configuration, one circuit might control the front brakes and the other the rear brakes.

The advantage of this design is enhanced safety. If a brake line ruptures or a caliper seizes in one circuit, the driver can still stop the vehicle using the remaining functional circuit. This prevents a complete loss of braking capability. However, the braking force will be significantly diminished, requiring the driver to apply more pressure to the brake pedal and potentially increasing stopping distances. Modern vehicles often employ more sophisticated braking systems, such as dual-circuit hydraulic systems with proportioning valves or electronic stability control, but the tvåkretssystem concept remains a foundational element of hydraulic brake redundancy.