Cheers for sharing this explaination - it has helped me better understand the workings of the controller. You are right in understanding that I am trying to throttle the FCV, the initial idea was to use the matched controller to deliver the dither/pwm signal, however @DrDiettrich suggested the use of a MOSFET - which I believe would be a lower cost and quicker to implement solution. Nonetheless, your description has vastly helped in better understanding the function of the components. Cheers.