I found a couple articles online about using transistors to run relays off the unregulated power source. But, when I try it out by placing an 7.4V battery across the collector to the emitter and trying to "activate" it through a resistor with a DC voltage supply on the base, the voltage supply reads 4V even with the voltage knob turned down to 0V. Trying to adjust the voltage higher increases the voltage, but doesn't activate the relay. If I don't use a resistor, the relay activates no matter what, even with the voltage knob turned all the way down. Anyone have experience with this?