Why only negative 24 vdc supply give in vibration measuring
system.

Answer Posted / darpan

The principle is that analyzer supplies a negative voltage
to transducer,who converts it into a frequency & sends it
across the probe.Now as the probe comes into the area of
rotor it creates a magnetic field & with it eddy current is
produced on the rotor side.Which changes the amplitude of
the frequency.It induces the voltage & remaining frequency
comes to the transducer through the return way.Transducer
converts it into the voltage .
Now coming back to the question The gap voltage has a
negative relation with the voltage induced i.e. as the gap
increases the induced voltage decreases.So to make it to
into a linear relation ship, negative voltage is supplied.
i.e

Gap Gap voltage
0 mm 0 vtg
1 mm -9 voltage
2 mm 18 voltage
& when the probe is in air it will have no induced voltage
so all -24 voltage without induced voltage will return bac

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