inverting circuit not inverting...

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inverting circuit not inverting...

Postby chicago_mike » 03 Jun 2012, 02:54

:scratch: :hmmm:

Made a simple inverting amp..but its not inverting....its part of an amplifier, so if the input is already inverted...would it not invert the signal?
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Re: inverting circuit not inverting...

Postby soulsonic » 03 Jun 2012, 03:36

I can't imagine a bad opamp not inverting correctly. Only thing a bad opamp does usually is stay silent or be really noisy. If it doesn't look inverted on the scope, it must be an issue with how you're reading it on the scope.

You can test it by mixing the supposedly-inverted output with the signal at its input. Just use two opamp sections and make one inverting and the other non-inverting with the same gain (just make them unity). have the same signal going to both stages and have the outputs summed together at equal volumes. They should cancel out and be silent. Best thing to do would be to have a balance control of some sort, so you can hear if the signal fades out when they are mixed equally.
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Re: inverting circuit not inverting...

Postby chicago_mike » 03 Jun 2012, 18:21

Here's the part of the schematic in question

we can clearly see an unused opamp. I am trying to take an inverted signal out of that to a power amplifier. So I can bridge the 2 amps in the head. :)

So far..every time I hook it up for inverting..its not doing it. Odd. Unless my scope is just not showing an inverted signal properly, but its a digital scope..I would think it woulndt matter and just show the sinal inverted.


HELP!!! :cry:
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Re: inverting circuit not inverting...

Postby chicago_mike » 03 Jun 2012, 18:28

Okay heres a crappy PAINT drawing of what I tried.

Did not work.

I also tried taking off of pin 1. Also...not working.

help!! :cry:
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Re: inverting circuit not inverting...

Postby chicago_mike » 03 Jun 2012, 23:40

It works! Just have to match the gain.

Need about 12dB I believe. :shock:
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