changing design
I couldn't understand, how the Original (microchip) Comparator Constant Current source worked.
The scenario is like this.
The -ve Vin constant.
The +Vin is below -Vin when the FET is fully off, and It is above -Vin when the FET is fully on.
So, at first the +Vin is Below -Vin, Output is Low and so the FET switches on.
As soon as Current builds-up enough, then +Vin will rise just slightly above -Vin, and FET should switch off. Then the current decrease, and +Vin will decrease slightly. Shouldn't this immediately switch on the FET again? Or is there some hysteresis in the Comparator and that determines the frequency?
I am also considering doing this instead, (since finding or making right size inductor seems too hard!) I will control the Duty Cycle of the PWM output to control the LAMPS brightness.
**broken link removed**