I have a photo flash, and I have the photo flash here, and this photo flash has a capacitor of about five thousand microfarads, a real biggie, and we can charge that up to a potential difference of one hundred volts, even though the batteries in there are only six volts, there is a circuit in there -- we'll learn about that later -- which converts the six volts to a hundred volts, and so we can charge up this capacitor to a hundred volts. 