op-amp help for a newbe

[KEN_KEN]

Hello all,

 I'm new to Workbench so I like to start by saying, thank for any and all help.

When I used the stranded scope the input sin was the same as the output sine in voltage, but when I tried the Tektronixi scope and put in 1 mv the output was 3.1 volts dc. Could someone tell what may be going. on.

Best regards,

 Ken

P.S. I would like to get an output of  40 khz square  @ 5v

[lacy]

Thanks for posting a picture of your circuit. Could you possibly include your circuit file also.

[KEN_KEN]

HI,

 Is this what you need?

Ken

[KEN_KEN]

I don't know if you need this file also.

Ken

[lacy]

I have been fighting with your circuit. I was unable to get any signal from from the first op-amp until I removed C2 and reversed the input connections. I also reversed the connections to the second op-amp. I now have a signal up to D4 and then it just disappears for some reason. It still isn't squaring the waveform though. I don't know if the information I have given is any help. but I thought I would post it for you. I will continue investigating and let you know if I find anything.

[lacy]

I don't know what to tell you on this problem. I have tried putting together integrator and differentiator circuits and I can't seem to get the signal to change from it's orignal form. Maybe someone can give us a clue as to why the op amps won't work as integrators and differentiators or if they have run into a simular sitiation.

[KEN_KEN]

Thank you for the help lacy ,

I'm having the same problem with a single stage amp. If you fell like looking at it I've attached a picture and the sim file.

Ken

[Peter_Bham]

When I opened and looked at the circuit U1A and U2B were not powered.  Was this missed or did it open wrong on mine?

Peter

[KEN_KEN]

It's my understanding that only pins 4 (V+) and 11 (GND) need to be powered on just one Amp. And in the past I did supply power to U1A and U2A unless there was something else wrong at the time.

Ken

[Peter_Bham]

That is correct.  For quad op amps only on set of power pins needs to be connected.  U1A will connect U1B, U1C, and U1D.  It will not connect U2A B C or D.  You will notice a red x on all the other power pins once you make the first connection.  Hope this helps.

Peter.