If a lighting ballast fails, do you change it out hot? That's a fairly common practice, but you can get electrocuted by 277V just as surely as from a higher voltage. If you're on a ladder, the fall ...

LED bulbs High-powered drop-in replacement MR16 TrackLEDs are designed to withstand voltage variations higher than the lamp's capacity caused by noisy or dirty AC or DC power supplies. These MR16 ...

The "longest train in Britain" is working through the night to replace ballast on the Norwich to London line. Working overnight to minimise disruption to train travellers, engineers for Network Rail ...