i read a buffer circuit using opamp and i do the same circuit.
i choose opamp is lm358n, and the input voltage from my circuit is 9v but my output voltage i measured is 11v.
can someone explain for me why ?
sorry because i am not good at english. so here is my circuit.

 

Something in sim settings wrong ? You should see 9V on output,
none of the CM range specs on LM358 being violated.

Regards, Dana.

 

Something in sim settings wrong ? You should see 9V on output,
none of the CM range specs on LM358 being violated.

Regards, Dana.

no, all i told in reality, not at sim, sim is only my circuit i want u know

 

Output of OpAmp have a heavy load on it connected to +12 ?
OpAmp getting hot ?

9 V connection to OpAmp V+ input, do you see 9V right at pin ?
If you touch pin with your finger do you see 50/60 Hz waveform on
output ? In other words is pin not properly connected to 9V.

Is V- OpAmp pin also at 11V ?

Sure sounds like connection/wiring issue.

Regards, Dana.

 

Output of OpAmp have a heavy load on it connected to +12 ?
OpAmp getting hot ?

9 V connection to OpAmp V+ input, do you see 9V right at pin ?
If you touch pin with your finger do you see 50/60 Hz waveform on
output ? In other words is pin not properly connected to 9V.

Is V- OpAmp pin also at 11V ?

Sure sounds like connection/wiring issue.

Regards, Dana.

lm358 can use with single output from +3 to +32v. i have adapter 12vdc so i used it to supply for opamp. and exactly at v+ input is 9v

 

If feedback connection shows 11V at V- pin then sounds like OpAmp is
bad.

Regards, Dana.

 

no, all i told in reality, not at sim, sim is only my circuit i want u know

If you share a picture of your physical circuit and connections (breadboard, PCB, etc.) I'd be happy to take a look and double check layout and connections. It's easy to get two wires switched backwards and not realize it.