Monitoring the current in railway lines to check signalling currents
At a glance
UK / India / Brazil
Currents of a few amps in the range 1 - 2 kHz are an essential part of the railway signalling system for determining where the trains are. When there is a fault the trains cannot run and it is important to find the fault with a minimum of delay.
Provide a current transducer to measure signalling currents in a railway line that can be moved around easily to trace the currents.
A U-shaped Rogowski coil was developed which could be simply dropped over the rail to make a measurement. This was a battery-powered unit and the integrator incorporated a high-pass filter that would allow measurement of the higher-frequency signalling currents but reject 50Hz signals which could cause interference.