Voltage Comparator

[Phu_Fu]

Hello Everybody!

I have a quick question want to ask you.  I am using multisim 10 and tried to test the voltage compartor, they have a lot of different IC chips voltage comparison and I am using LM2924N. But some how it is not work right, can you look over my circuit and give me your suggestion about the simulation.  Thank you for your help, have a nice day.

[lacy]

This is another one of those op amp problems that has been discussed before. NI is aware of these problems and have yet to correct them even in 10.1.

If you look at the model you will find that it says  in the first comment line "EWB 4-3 Terminal Op Amp". These do not work in Version 10 at all it seems. Most of these models are listed in the  Model manuf./ID window of the component as IIT/LM2924. If the model manuf. is listed as "IIT" then check the model file for the above comment line. If it says this then nine times out of ten it won't work. Choose a different one, preferably one with a model listing like "IIT/LM2924-2" or "IIT/LM2924-3". These last listings should work as they are 5-terminal op amps.

If you really need a model for the LM2924 that works I will see what I can find, but I make no promises as to being able to find any.

[Phu_Fu]

Thank you so much, I spend couple hours on that circuit to test.  But I did not realize it, now I'm understanding why.  So do you know any IC chips on the Multisim 10 that should work for voltage comparator.  Thank you for your reply, have a nice day.

[lacy]

There is a whole category under ANALOG>VOLTAGE COMPARATORS that should work. Just be sure to find either a manufacturers model of one of the models the have a -2 or -3 in the Model name.