It is possible to step-up voltage without using a transformer. The property of an inductor to build up a high counter-electromotive force (cemf) can be used to flash gas discharge tubes and light neon bulbs and small tubes from very small batteries. All you need to do is connect a fairly large inductor (.5mH or higher works best) in parallel to the bulb or tube and then attach the inductor to a square wave pulse generator. The result should be the tube or bulb glowing, sometimes very brightly depending on the inductor used, the input voltage/current, pulse rate, and the bulb or tube characteristics. It is important to have the neon bulb, etc. lighting, if it doesn't the cemf will come back to the output transistor and possibly ruin it. When the bulb is glowing the gas is a low resistance, therefore shorting the cemf. The bulb or tube you use will also protect the rest of the circuit. For the pulse generator, a low frequency 555 timer circuit or signal generator will do. Experiment with the inductor, I have gotten neon bulbs to give off almost white light.