Hi All,

I do not find find whats wrong with this window comparator circuit in LT Spice Simulation ?
Could

 

The LT1413 is a dual op amp, not a comparator. You cannot simply connect its outputs together as you would with an LM393 or other device having open-collector NPN outputs, because when one op amp is trying to output high and the other op amp is trying to output low there will be a conflict.

 

Hello,

As said, the outputs of the opamps can not be connected together.
If you want to continue to use the opamps , use diodes on the outputs.
You can configure AND and OR with the diodes as followed:



https://electronics.stackexchange.com/questions/131860/diode-logic-gates

Bertus

 

Why all of the unnecessary wire jogs and gray space?

 

Hello,

As said, the outputs of the opamps can not be connected together.
If you want to continue to use the opamps , use diodes on the outputs.
You can configure AND and OR with the diodes as followed:

View attachment 211981

https://electronics.stackexchange.com/questions/131860/diode-logic-gates

Bertus

I tried with diode output and it did not work.

 

See

 

I tried with diode output and it did not work.
View attachment 212207
View attachment 212208

Hi

I think it is working
It will always be on
The diode is in or configuration

You want trigger when 4<Vi<8

but for the output you used or gate
That is (Vi>4 OR Vi<8)
Every single number satisfies this equation hence output is high

So use AND gate. (Vi >4 AND Vi <8)

 

Good catch, @Zeeus .

Also, D2 does not appear to be a "normal" PN junction diode and it may be complicating things. The other diode is a 1N4148.

 

I tried with diode output and it did not work.

Turn the diodes the other way round and connect R4 to +12V instead on 0V.

 

Thanks Guys for guiding me !
Now i understood the concept and circuit is working.