I bought a couple of wind-up dynamo LED lanterns in anticipation of the winter power cuts. They have a 6volt charging socket but there is no indication of the polarity on the case next to the socket and no instructions as to polarity. My understanding is that the usual convention is that the central pin is positive and the outer sleeve is negative on the charging plug. Is this likely to be correct?
An adaptor was not included but I have got a regulated DC adaptor that can be set from 1.5 to 12volts with either a positive or negative tip.