Electronic Transformers, Premature Failures

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There may be a reason why some types of electronic transformers supplying 12 volt lamps fail sooner than expected.

Has anyone made any observations as to whether there are less failures where there is only one transformer compared to where there are two or more transfomers on the same circuit.

Reason for asking is as follows.

Some electronic transformers chop the incoming mains supply ON and OFF at a high frequency ( around 40,000 time per second ) as part of the process of creating a 12 volt output from the 230 volt input. This can cause significant high frequency voltage fluctuations on the supply if the transformer does not have adequate filtering.

Where there are two or more transformers on the same supply the high frequency fluctuations generated by each transformer may be dis-rupting the operation of the other transformers. This could cause the "transformer" action to become in-efficient resulting in excessive heating and / or electronic stress on components.
 
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Not harmonics as such.

Beat frequency creating low frequency "rumble" on the supply where the rumble frequency is the difference between the chopping frequencies in each of the transformers.
 
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Sounds unlikely. I would have expected the interference between two or more oscillators to result in their synchronisation. Or if the frequencies are very different, synchronisation on a common harmonic.
 
No.......Harmonics are derived from a single frequency that is not a pure sine wave. Beat note freuencies are derived from two frequencies.

If the two frequuencies are ( for example ) 1000 Hz and 1005 Hz and pure sine waves there will be beat note frequencies of 5 Hz and 2005 Hz

If it was a single un-distorted sine wave of 1000 Hz then upper harmonics would be 2000 3000 4000 etc and lower harmonices at 500, 250 125 etc

There would be other harmonics at non integer multiples of the 1000 Hz, the intensity of these would depend on the type and amount of distortion.
 

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