The transducers of Witt enable a very accurate measurement of driving voltages and currents in electrical isolation.
The transducers are used in DC-powered vehicles as well as in stationary facilities. The voltage that falls off an external current shunt is transmitted potential-free. Thus, it is possible to measure on the “hot” side of the traction power supply.
It is possible to measure the absorbed power by the pantograph in the inside of the railway engine. The TD 100 can also measure the power delivered by a substation or a sectionalizer.
The entire electronic is placed in a fully isolated plastic housing. The 4- 20 mA outlet is wired in a way that in case of a fault 0mA will flow and such the following stages can detect an error.
The voltage that drops out of the current shunt is limited (transient protection) and filtered by the device. Next this voltage is transduced into a high proportional frequency (60-800 kHz) and transferred by a optic fibre cable which is completely galvanically isolated. A subsequent frequency/voltage converter generates a proportional voltage that will – after a filtering in a final stage – be converted into electricity.
The necessary auxiliary voltage is provided in two separate transducers of the primary and the secondary side.
The following products are available: