信号改造工程电码化JMJ和FMJ电路试验的必要性

Necessity of JMJ and FMJ Coded Circuits Test for Signal Renovation

机车信号从原来的辅助信号发展为控制列车行驶的主要信号,当机车信号接收错码或无码时,机车会自动停车。在电码化电路试验过程中一般注重发码频率的测试,对电码化电路中的接车发码继电器(JMJ)和发车发码继电器(FMJ)的励磁条件没有进行严密核对,只确认在开放信号后JMJ和FMJ的吸起,没有对JMJ和FMJ的失磁时机进行确认,当上、下行励磁条件交叉时,肯定会留下安全隐患,造成行车事故,所以必须对JMJ和FMJ电路进行完整试验。

With the rapid development of China's railways,the cab signal has developed from the original auxiliary signal to the main signal to control the train running.When the cab signal receives wrong code or no code,the locomotive will stop automatically.In the process of coded circuit test,attention is generally paid to the test of sending frequency,the correct frequency of various code types,the correct outdoor reception and the correct entrance current.The excitation conditions of JMJ and FMJ in the coded circuit were not strictly checked,only the JMJ and FMJ energized after the signal at clear was confi rmed,and the JMJ and FMJ release time was not confi rmed.When up and down excitation conditions cross,there will be safety hazards and operation accidents,so it is necessary to carry out a complete test of JMJ and FMJ circuits.