comparator in proteus

[mshh]

i used lm339 comparator with the attached circuit .i want to drive Mosfet but the output in simulation is 2.2 v on the pin1 of the comparator .however it should be Vsat. when i decreased R1 to 10 ohm the output on led increased to 5.1 v .what is the problem . i want to get 11 v from this circuit at least and that will only happened if i put R1 = 0.

Is there any simpler circuit than this one?

 

[pjmelect]

R9 should be 100R at least not 10R, the max current sink is 18mA.

 

[pjmelect]

R9 should be 100R at least not 10R, the max current sink is 18mA.

Sorry I made a mistake and for some reason I am unable to edit my post. R9 should be 1K not 10R.

 

[mshh]

i told you it was 1K and he output on the led was 2.2 V however it should be Vsat.at least 10 v to run the mosfet.

 

[pjmelect]

The output will only be 2.2V or so because of the LED forward voltage drop!!!

 

[ud23]

what is your Vref voltage ? and why use comparator for driving the mosfet? I mean comparator output would be zero when Vin reached to Vref or greater then Vref.for less then Vref it should be output 14 or 15 v if your supply is 15v.

 

[mshh]

ok , it's working
thanks

 

[ud23]

ok , it's working
thanks

what is the problem and how you rectified the problem? please tell how its works so it is helpful to others.

 

[mshh]

the problem was the led . the output was the voltage drop 2.2 i didn't know that this voltage was the voltage drop . when i replaced it with mosfet the output was 15 v .Is there any problem to use comparator to drive mosfet ? vin is 0-10 v it is also a ramp . Vref will be ramp also but with different frequency .
thanks