The TM57 Microswitch is a DPST (1NC 1NO) switch used in railway control circuits.
The TM57 switch is a TM patent that overcomes the drawbacks of other similar products, in particular it ensures that no significant interruptions occur in the circuits in which it is inserted as a result of the vibrations normally generated by the passage of rolling stock on the tracks. At the same time, the TM57 switch ensures minimum contact resistance.
Operating tests with random vibrations, according to N.T. RFI IS402 level 5V, on the TM29 Switch Position Detector equipped with Micro TM-57, have verified that the electrical control circuit of the device does not suffer interruptions of more than 10 milliseconds.