Super cheap Dimmable LED Driver (cost under $3)

You are completely correct, David. But the voltage has to remain steady. I found a power supply for a sensitive electronic that provides 9v up to 1A and I use it for a 10w LED directly hooked up. If the voltage is too high, the current jumps up really fast. What started as a simple test (the 10w light above) has become a useful light. It is the only light in my house that I can read tiny numbers from tiny capacitors and other electronics.