Train Tech Smart Light - Arc Welding The Smart Light developed by Train Tech is a new system which can easily be fitted into buildings, locomotives, vehicles and other areas of your railway. The light is just 1cm square and simply connects to a 9 - 16 volt power supply and only requires 2 wires and no additional setting up. It can also be fitted to a battery for portable usage. This set simulates a the effects of a arc welder hard at work. The sequence includes the flickering white light and the glow of the red to show the welder heating up. This item looks great in any industrial scene or country garage.