I am about to test a circuit including this integrator and decided to add a LED turning on when Vin is within window.



The actual Vwin (comparator's output) is quite close to what LTSpice predicts.



Remaining space in the crowded board, allows just a TO92 and few resistors. All what I tried with BJTs created problems to the integrator or did not work.

Could anyone come with an effective design? I spent one full journey trying in LTSpice because I do not dare to rsik the only two pairs of JFETs I got (2 x 2N5461 Pchannel + 2 x J310 N channel).

Please note: I need to add a LED and NOT to modify the integrator.

Just in case I am adding the .asc file plus model and subckt

Gracias for any ideas.

 

It's not clear to me exactly what you are trying to do and why (how) it doesn't work.
Can you post a complete circuit including the LED and BJT.

What's with the strange blue schematic background color?

 

Sorry Carl. Too many things I tried and no one worked.

The LED has to go ON when Vin is within UL and LL limits.

 

hola at,
Try this option.
E

 

You might want a resistor to ground on the gate of the FET.