Difference between revisions of "Driver"

This driver uses a field effect transistor (FET or MOSFET) in combination with a microprocessor to control current to the LED. The FET has very low resistance (lower than running the full current through the microprocessor) and can be controlled via PWM by the microprocessor.  Without PWM, it is basically like running the light on direct drive so there is no protection of the LED. Some FET drivers add a linear regulator 7135 so the need for PWM on lower modes is reduced. This multichannel approach lets the driver limit the current to 350mA (instead of unlimited through the FET) and use PWM as needed to work from there. Also the 350mA channel gives more uniform low levels whereas the levels from the FET vary with battery strength.