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Ripple on low voltage

Peterd
I look after a small fairground type railway. It is powered via a transformer and full wave rectifier and runs at around 35 volts. At recent inspections it has been noted that it fails as there is around 24 volt ripple on the 35 volt dc, which is not surprising as there is no smoothing. Apparently according to the person undertaking the inspection, who states it is to bs7671, the ripple should be no more than 10% ripple, however I cannot find any such requirement.

Has anyone got any experience of this type of thing, I am loathe to add a capacitor to smooth the dc - it would have to be probably around 0.1F, and ripple current in it could well be a problem.

Any thoughts on this would be appreciated, is there an actual requirement on ripple, or is it OK to just have full wave rectified dc as long as the peak voltage does not exceed the elv limits of 120v dc or 50 v ac rms .
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    Interesting, I am  happy to be corrected, I admit was expecting something more like the 4 track DC railways of the London underground and the Isle of Wight - though the main safety in all of those is the fact that the rails are only energised in sections when the train needs  it - at that point being electrocuted is a far lesser risk than being run over, and the accident figures bear that out.,

    I can imagine on a short run the sectional energising idea  is largely  irrelevant. I am aware of things like dodgems being supplied at  90- 100V DC with an earthed electric floor, and 'out of reach' being the normal safety measure, the contact  spoon on the car, and the mesh being too high for the tallest user.

    Assuming then it is earthed, the killer  question is how real is the risk of the power rails  being touched while live, with enough contact area to skin to be a hazard - I;m not convinced that smoothing is really needed or desirable.

    M.
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    Interesting, I am  happy to be corrected, I admit was expecting something more like the 4 track DC railways of the London underground and the Isle of Wight - though the main safety in all of those is the fact that the rails are only energised in sections when the train needs  it - at that point being electrocuted is a far lesser risk than being run over, and the accident figures bear that out.,

    I can imagine on a short run the sectional energising idea  is largely  irrelevant. I am aware of things like dodgems being supplied at  90- 100V DC with an earthed electric floor, and 'out of reach' being the normal safety measure, the contact  spoon on the car, and the mesh being too high for the tallest user.

    Assuming then it is earthed, the killer  question is how real is the risk of the power rails  being touched while live, with enough contact area to skin to be a hazard - I;m not convinced that smoothing is really needed or desirable.

    M.
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