Talk:VR Class Sr2

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DYK	July 25, 2012

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motor noise

diff - removed : The inverter circuitry contains a large conderser battery and electromagnetic interference suppressors. Thus the Sr2 does not produce the loud sound "play the octave" on startup, like many other GTO-thyristor driven locomotives do (e.g. ÖBB Taurus).

I find this dubious - assuming it uses variable frequency drive (if it doesn't the explanation is still wrong) then it is generating AC electricity at audio frequencys - noise comes from vibration of components under varying electric fields (eg the low frequency hum from power cables or transformers is of the same origin) - the way to prevent it is either not use AC or fix the components and their electrical parts so firmly that they cannot vibrate - a "condensor battery and electromagnetic interference suppressors" will not prevent this. It's quite possible that the machine makes less noise than OBB Taurus, or even doesn't use variable frequency - but the explanation given doesn't seem correct at all.Sf5xeplus (talk) 05:26, 19 January 2011 (UTC)[reply]