Opamp circuit with -33KV

Thread Starter

BrainInVat

Joined Jul 20, 2012
3
I am new to electronics and ltspice. I am trying to make an opamp integrator, but I am getting some very weird results. I am supplying the opamp with 12 V so I would not expect the output to be more than 12 V or less than -12 V, but my simulation gives an output between -32.8111 KV and -32.8101 KV. What am I doing wrong?

Thanks
 

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bountyhunter

Joined Sep 7, 2009
2,512
I am new to electronics and ltspice. I am trying to make an opamp integrator, but I am getting some very weird results. I am supplying the opamp with 12 V so I would not expect the output to be more than 12 V or less than -12 V, but my simulation gives an output between -32.8111 KV and -32.8101 KV. What am I doing wrong?

Thanks
Using a simulator to see what a circuit does that would take three minutes to build on a proto board.

On the upside, at least the lie the computer told you was so far off you noticed it was wrong.
 

Thread Starter

BrainInVat

Joined Jul 20, 2012
3
I don't have any actual parts yet, so building the circuit would take more than 3 minutes. Also starting small is a good way to learn. I would not be able to debug a more complicated circuit at this point.
 

bountyhunter

Joined Sep 7, 2009
2,512
I don't have any actual parts yet, so building the circuit would take more than 3 minutes. Also starting small is a good way to learn. I would not be able to debug a more complicated circuit at this point.
I read in the first post:

I am trying to make an opamp integrator
That takes an LM324, a ceramic cap, and maybe two resistors.

Believe me when I tell you: buying a proto board and building things is the best way to learn.

But, what do I know..... just one old man's opinion. I could very well be senile and would have no way to know for sure....?
 

crutschow

Joined Mar 14, 2008
34,459
The simulation 'failed' because you didn't place a ground node on the Op Amp power supply.
Also for that circuit you should have separate plus and minus supplies (connected to ground). That op amp is not designed to operate from a single supply.
 

Papabravo

Joined Feb 24, 2006
21,226
I assumed it meant "asci" type file. Whatever it is, it won't open.
It is an ASCII text file describing the netlist of the circuit. What program are you trying to use to open it? If you are using a Windows machine you may have to get clever with "file associations" to open it as a text file.
 

Audioguru

Joined Dec 20, 2007
11,248
It is an ordinary LTspice file. It shows the opamp with a single (positive) supply and its (+) input is wrongly connected to 0V so it is not biased to work properly.

The simulation is not set up correctly so it takes forever to finish (or never finishes) the simulation.
 

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