A Study on the Improvement of Test and Diagnosis Device for Audio Frequency Track Circuit
Jang-Kyu Kang, Jae‐Chul Kim · Journal of the Korean Institute of Illuminating and Electrical Installation Engineers · 2010
We studied on performance improvement of TTM(TI21 Test Meter) that is test and diagnosis devices for jointless audio frequency track circuit on Korean electric railway TI21 standard. Upgraded devices is AD-TTM(Advanced TI21 Test Meter). This can measure alternating frequency USB(Upper signal band) and LSB(Lower signal band). In the audio frequency track circuit, ±17[㎐] of nominal frequency are demodulated and supplied to track relay through AND gate. It is important that measurement function which is error between USB and LSB. Need of AD-TTM will stand out in the electric railway system because this is simple and accurate rather than the former device.