"First, in regards to frequency shift due to overdriving a fluorescent bulb, the light color WILL NOT change. The process is governed by laws of quantum physics, which guarantee that it will not shift color. I will explain.
This is the process that happens, either 60 or 120 times a second with magnetic ballasts, or 22,000 to 45,000 times a second with electronic ballasts. The ballast initially provides a high voltage to the filaments at each end of the fluorescent lamp. When the voltage reaches a critical level, the gas in the tube (mainly argon with a little mercury) suddenly becomes ionized, and current rushes through the tube. “Ionization” means an atom now has more electrons than it normally would contain in its outer shell. In this case, extra electrons have been induced to go racing around the “conduction band” of the mercury atoms to get to the other side of the tube. Sufficient voltage pressure is created by the ballast to force the gas into ionization in the fluorescent tube.
In the process, the electrons in the outer shell of the mercury atoms randomly pick up extra energy and go into a higher sub-orbit that normal. Those electrons then drop back to the original orbit as soon as possible, which releases an EXACT amount of energy (a quantum level) as a photon. That photon will ALWAYS be an exact color frequency based on the atom and it’s outer-shell electron. As far as the mercury atoms go, this will actually be ultra-violet light (UV), and is not the final color output of the lamp.
The actual color that is emitted from the tube is based on the type of phosphors, which coat the inside of the tube. The same process that I just described above is repeated there, at the phosphor coating, when the photons from the mercury atom hit the tube. There the UV photons are absorbed by the phosphor compounds and re-emitted at the SPECIFIC QUANTUM LEVEL, or color, as the phosphors had been designed to emit. The photon(s) emitted cannot possibly violate the energy levels set by nature. More ENERGY (by overdriving) will translate to more LIGHT. In this case, it is just as if you shone more light on an object, and it got brighter, not colored differently."
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