自动控制文献翻译——编码轨道电路是铁路信号史上一个重要的进步。而稳定的能量轨道电路达到目的了，编码轨道电路能更灵活，这是稳定的能源类型无法达到的。

一个关于编码轨道电路的简单定义是：轨道电路中稳定的轨道电流在每分钟内中断一定的次数，从而形成包含均匀周期性脉冲的代码，这样便形成了编码轨道电路。通过使用每分钟内不同脉冲数量的代码，导轨电路中的电流就可以用来反应功除火车占用及断轨以外的其他信息。

为轨道编码电路提供单独的能源，可以避免，由于短路、断路或任何其他外部影响，如电容耦合，互感及干扰电流等的影响而造成错误操作。编码轨道电路提高了轨道电路的分路灵敏度，更好的防护了了有车占时分路的瞬间消失现象，提高对断轨及绝缘节破损现象的检查。

在轨道电路中无论混入的干扰电流是直流还是交流，编码轨道电路均能将其干扰最小化甚至克服。干扰电流会导致编码轨道继电器出于一直吸起或落下状态，其结果与分路时无编码信号是一样的，好像有车占用该区间，这样就严格的导向了安全测。

在一个稳定的能量轨道电路，列车分路时，轨道电压必然会降至低于轨道继电器的释放值，以确保轨道继电器能够安全落下。在编码轨道电路中，列车分路时，仅仅需要将轨道电压降至轨道继电器吸起有效值以下，阻止轨道......

The coded track circuit is an important advancement in the history of railway signaling. While the steady energy track circuit serves its purpose well, the coded track circuit affords a more flexible arrangement, not attainable with the steady energy type.

A simple description of a coded track circuit is a track circuit in which the steady rail current is interrupted a predetermined number of times per minute so as to form a code consisting of uniform recurring impulses of rail current. By using codes of different number of impulses per minute, the current in the rails can be employed to perform functions other than detecting the presence of a train and broken rails.

The use of coded energy in track circuits provides, for all practical purposes, immunity to improper operation due to crosses, grounds or any other foreign influence such as capacity coupling, inductive interference or stray currents. It also provides higher shunting sensitivity, improved protection against intermittent loss of shunt, improved broken-rail detection and detection of defective insulated rail joints.

Where foreign current in an area is experienced, its effect may generally be surmounted or at least minimized by the use of coded track circuits, either d.c. or a.c. Foreign current may cause the coded track relay to be continuously energized or de-energized, resulting in no coding action which is equivalent to shunted track. This would cause a restrictive aspect to be displayed, the same as if a train were in the block.

In a steady energy track circuit, a train shunt must reduce the rail potential below the track relay’s drop-away value in order to obtain track relay release. In a coded track circuit, however, the shunt need only reduce the rail potential......