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33 minutes ago, LittleWatchShop said:

@JohnR725gets to my reasoning...re virtual ground.  I want to measure with respect to a known potential.  The virtual ground circuit may be the issue. 

One of the things that was bothering me about the virtual ground is? I was looking at the na5534 data sheet and The power supply bypass capacitors become interesting with a virtual ground as they don't actually talk about that. If you're using a dual supply then one bypass capacitor from each supply lead as close as physically possible to the IC to ground. On a single power supply like we have here only one capacitor is needed between the positive and the power supply ground which is negative the battery. But for now using the virtual ground as the power supply ground which just seems weird in some strange way? In other words I think you only need one bypass capacitor from the positive terminal to the negative terminal which corresponds to the battery plus and minus and the bypass capacitors for the power supply should not be going to the virtual ground. As it's more of a virtual for the signal not for power supply bypass.

 

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28 minutes ago, JohnR725 said:

One of the things that was bothering me about the virtual ground is? I was looking at the na5534 data sheet and The power supply bypass capacitors become interesting with a virtual ground as they don't actually talk about that. If you're using a dual supply then one bypass capacitor from each supply lead as close as physically possible to the IC to ground. On a single power supply like we have here only one capacitor is needed between the positive and the power supply ground which is negative the battery. But for now using the virtual ground as the power supply ground which just seems weird in some strange way? In other words I think you only need one bypass capacitor from the positive terminal to the negative terminal which corresponds to the battery plus and minus and the bypass capacitors for the power supply should not be going to the virtual ground. As it's more of a virtual for the signal not for power supply bypass.

 

So I should remove c19.....? 

"the bypass capacitors for the power supply should not be going to the virtual ground"  They are going to the virtual ground.  which is pin one of U5

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1 minute ago, CWRNH said:

So I should remove c19.....? 

"the bypass capacitors for the power supply should not be going to the virtual ground"  They are going to the virtual ground.  which is pin one of U5

Sorry U1 not U5

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1 minute ago, LittleWatchShop said:

Right now, your have a dc problem.  Unless your ground is oscillating, you need to solve the dc issue.

No clue what you mean, sorry.  Looks to me like it is wired exactly like the original schematic which is a known working circuit.image.thumb.png.67de1d3d43683ae5c67d614cf7ed5e9a.pngimage.thumb.png.280569a3a7a3ededb9fd48181ac287eb.png

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3 minutes ago, LittleWatchShop said:

Right now, your have a dc problem.  Unless your ground is oscillating, you need to solve the dc issue.

I have an agreement ignore my posting for now. Deal with your DC power issues. Then we can deal with the virtual ground issue later as it's not the reason you're not running.

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1 minute ago, JohnR725 said:

I have an agreement ignore my posting for now. Deal with your DC power issues. Then we can deal with the virtual ground issue later as it's not the reason you're not running.

I will remove C19

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7 minutes ago, CWRNH said:

I will remove C19

I would leave it alone it's not the problem. A minor issue with the data sheet in that they should have given these separate part numbers perhaps? You'll notice in the attached image the three pin package has three pins. The eight pin package has of course more pins to do things with. Like have a noise reduction pin which requires a capacitor.

noise reduction.JPG

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11 minutes ago, JohnR725 said:

I would leave it alone it's not the problem. A minor issue with the data sheet in that they should have given these separate part numbers perhaps? You'll notice in the attached image the three pin package has three pins. The eight pin package has of course more pins to do things with. Like have a noise reduction pin which requires a capacitor.

noise reduction.JPG

That's what I thought.  I thought I had the power all run properly.  Am I powering the pins 4 and 7 wrong on the op amps?  The original schematic has 5 and 7 pins swapped in orientation but still should be right the way I wired it.  pin seven is + and pin 4 is -.   Pin 3n on U2 U3 and U4 go to virtual ground.  All bypass Caps go to Virtual ground.   I cannot see where I made the mistake.  

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image.thumb.png.6543108fd1d708b8180c2cbcbb9c427f.png

This is how I have the powers and virtual grounds wired.    Does this look correct?

 

On the original schematic he said he only put bypass caps on the buffer and first stage power pins.  Could that be what is causing my problem?  I have caps on all the + and - pins.

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1 hour ago, LittleWatchShop said:

As I have said, and you have proven...pin 6 is shorted to V-.  Until you remedy that, I have no more answers

I am assuming that the references to this integrated circuit LT1115? Even though I did a nice job of explaining it just to make sure were on the same page here I'm redoing it. It does appear to be the pins six is shorted to something I am going to take his word on it that's B- I don't feel like tracing it out that far. So that means your output of your integrated circuit is being shorted to the negative power supply lead which is going to be undesirable. Or basically it's not going to work in this configuration I would fix that.

2 hours ago, CWRNH said:

On the original schematic he said he only put bypass caps on the buffer and first stage power pins.  Could that be what is causing my problem?  I have caps on all the + and - pins.

Usually whenever you're building a circuit it's always wise to read the technical sheets and see what their recommendation is for wiring and power requirements.

Then there is the virtual ground confusion or the confusion may be I'm having only? Traditionally with op amp circuits there would be two separate power supplies connected together to form the power supply ground as I'm going to call it. In a single power supply circuit usually the negative terminal is the ground. If you're running your op amps on a single power supply its reference to the ground unless? Unless you have a virtual ground or in this case I'd like to call the signal ground. This means that you have two separate grounds in the circuit everything related to the circuit and then the ground for the power supply.

Looking at the tech sheet for the op amps for instance using a single power supply their grounding recommendation is a capacitor and they spell up specifications for which I'll skip over wired as close as possible between the positive power terminal and the negative terminal on the integrated circuit. But you have this wired up like a double power supply and have connected each of the power leads to the virtual ground. The virtual ground I don't think is actually designed to be a power ground.

 

pin six issue.JPG

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6 minutes ago, JohnR725 said:

This means that you have two separate grounds in the circuit everything related to the circuit and then the ground for the power supply.

For a battery powered circuit, everything is floating, so the classical meaning of "ground" does not apply.  For opamp circuits such as this, it is convenient to call the mid-rail voltage "ground" but beyond convenience, it has little meaning.

As far as current capability, the virtual ground generator can source and sink 20mA.  The only place any 'real' current is required from ground is via the 680 ohm resistor (which is not necessary IMO).  It is less than the 20mA spec limit.

I am pounding my head against my screen and my fists against the keyboard...why...Occam's Razor.

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2 hours ago, LittleWatchShop said:

As I have said, and you have proven...pin 6 is shorted to V-.  Until you remedy that, I have no more answers.

I repaired that when you pointed it out and thought I had mentioned that I repaired it in two replies.  Was there another one shorted?

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This circuit supposedly is proven to work, I found it way back in this thread.

image.thumb.png.10d730ea560b487252d11719abca2e71.png

I used the schematic to create a new schematic ( below ) using TINA so I could simulate it

image.thumb.png.b823102466588a304ae09dafe86ac5a2.png

I then created this board based on the new schematic using express PCB

image.thumb.png.6509c229883bf6040f6712d840529dbd.png

I then made the board.  It didn't work. 

It was pointed out several replies back that there was a short.  I fixed it right away and tested the board again.  Still didn't work (may have blown an IC or all of them).

So considering the original schematic was a working circuit, and I basically just copied it, it should work if I wired everything correctly.  So that being said, I must have failed miserably somewhere in translation.

Yes I do have, and have read all the tech sheets for the components, a lot of which is a bit over my head but I thought I had a decent enough grasp on it to build this simple project.  Apparently I was wrong (nothing new).  I very carefully read up on the rail splitter and thought I had it correct.

I looked over the entire board for more shorts, I found no others. 

Eventually I will learn this stuff and get proficient like you all but it takes time.  So far every new endeavor I have started has turned out successful, this one my not... LOL!  I have plenty of working timing machines, this is a project for which I hope to learn valuable skills from more than build another machine.  I have several ideas that, if I can make work, will be very useful to watchmakers like myself that actually are building watch escapements from scratch.  I appreciate all your help, and thank you all very, very, much.

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