Dimmable Joule Thief Buck circuit with MOSFet PUBLIC

A quick and easy circuit to control a 10v 200mA LED array using a 2N7000 MOSFET. Dimming is done through R2.

When the MOSFET (2N7000 or BS170) switches on, current flows through BOTH the LED and the coil, charging it up. When the coil becomes 'saturated', the transistor switches off, and the stored charge is dumped through D2 into C1, keeping the LED array bright.

R1 and R2 acts as a voltage divider to the gate of the transistor, allowing us to change the brightness of the LED array.

The Array is available for under US$3 from DealExtreme, sku: 195326 (ignore the voltage specs); http://dx.com/p/3w-330lm-5500k-6-5630-smd-led-white-led-emitter-aluminum-plate-110-240v-195326