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So what else is available in state-of-the-art LED controls? It seems what we really need is a sort of closed-loop device that looks at the incoming voltage and maintains the constant current feeding the LEDs even as the voltage fluctuates, all of that while keeping minimum heat. And, you guessed it, the device exists! It's called a DC/DC Buck Power Converter. It is an expensive way to supply energy to LEDs, but it has all the advantages that we are looking for.

The Buck Power Converter is a complex little device, but its function is somewhat simple. To describe it in layman's terms, it basically takes an energy source and switches it on and off. During the "on" state, the energy is stored in an inductor and during the "off" state, the inductor releases knytan the energy to the LED. The ratio of "on" and "off" time is called the duty-cycle. For example, a 25% duty-cycle would pass to the LED only 3V from a 12V source. All we need to do is control the duty-cycle according to the input voltage and we get constant current feeding our LED.

The Buck Power Converter controller does this by monitoring the current to the LEDs through a current-sense resistor and adjusts the duty cycle either up or down to correct the current in order to match the LED optimal current requirement. This way we can push the envelope on the brightness of the LEDs without worrying that the source voltage fluctuations will take us past the maximum rated current of the LED and end up with a fried LED cluster.