The 1 watt LED driver circuit shown in this article can be used for illuminating a 1 watt LED for quite sometime from a source that may be as minimal as a 1.5 V AAA cell..
The circuit is obviously based on boost driver technology, other wise driving such a huge load w such minimal source is beyond imagination.
1 Watt LED and 1.5 AAA Cell
A 1 watt LED is relatively huge when compared to a 1.5 V AAA cell source.
A 1 watt LED needs minimum 3 volts supply which is double the above cell rating.
Secondly a 1 watt LED would require anywhere between 20 to 350 mA of current for operating, 100 mA being a respectable current for driving these light machines.
Therefore using a AAA penlight cell for the above operation looks very remote and out of question.
However the discussed circuit here proves all of us wrong and successfully drives a 1 watt LED without much complications.
THANKS TO ZETEX, for providing us with this wonderful little IC ZXSC310, which requires just a few ordinary passive components for making this feat possible.
The diagram shows a rather simple configuration, which is basically a boost converter set up.
The input DC of 1.5 volts is processed by the IC to generate a high frequency output.
The frequency is switched by the transistor and the schottky diode via the inductor.
The rapid switching of the inductor provides the required boost in the voltage which becomes just appropriate for driving the connected 1 watt LED.
Here, during the completion of each frequency, the equivalent stored energy inside the inductor is pumped back into the LED generating the required voltage boost, which keeps the LED illuminated for long hours even with a source that's as small as a 1.5 volt cell.