[Al Skierkiewicz]

Bob,
You need to check the ratings on the LEDs. It is unusual to have a stock LED listed at 100 ma unless it is a multi LED in a single package. Second, I usually use a 2 volt Vf as a rule of thumb unless I am dealing with a special device of known specs. So using a 9 volt battery will not allow 5 LEDs in series. I actually question the need for this much output. However, 3 LEDs in series with a 120 ohm resistor in each string should work fine. The 2N2222 is fine for this service as well. If it seems that the transistor is getting too warm, you can use two transistors by paralleling the base of each transistor. Although you do not show the transistor in your diagram, normal operation uses the emitter tied back to the negative terminal of the battery. You would then tie the left side of your diagram to battery positive and each of the resistors to the collector of the transistor. When you use multiple transistors, do not tie the collectors in parallel. Tie one or two LED strings to each collector and you should be fine. Build up a driver board with several transistors and terminals for each collector. Then add a string and see if that gives you the desired result. Add a string and try again. No current will flow in an open circuit collector. Battery drain is going to be significant but you should have enough reserve in a 9 volt battery for a weekend of fun. You could even add a "power" switch to turn on the strings. i.e. 1, 2, 3, and "ludicrous power!"