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It won't run. ERROR: C:\Users\User\Downloads\Pease MFB BP filter (2)\Pease MFB BP filter (2)\OpAmp.sub(7): This sub-circuit name is not defined.
X1 3 2 8 4 1 UniversalOpAmp
??????????? ^^^^^^^^^^^^^^^

I find I have to download my uploads to Downloads and run from there , to check that the upload does work.

The following items have been added to the Files area of the [email protected] group.

• /Temp/Pease MFB BP filter (2).zip

By: Tim Hutcheson <thutcheson@...>

Description:
Pease Filter with an OpAmp.sub that wraps the UniversalOpAmp device for easy substitution by name for any pincompatible opamp (I think). :-)

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It's 'Solder pads for test leads'. It buzzes if R10 is low enough, so it's a continuity tester. I suppose the PTC in the picture is protection against the test leads being connected to a significant voltage.

On Fri, May 16, 2025 at 11:01 AM, Klaus W?rner wrote:

I try to simulate a testofon, but it doesn't work. Has anyone an idea, why?

I don't know what a testofon (or testafon) is, but I think it is a buzzer?? Does it make an audible buzzing sound when the leads connect?

?

From the looks of the schematic, it seems like there should be a voltage source connected at the far left end.? Otherwise, why would the diodes be there?? I do not know how to speak German so I don't know what the picture says.

?

If the rest of the circuit is supposed to be an oscillator, then maybe it needs more time to start oscillating.? Or, maybe it needs a smaller timestep.? If I change the simulation command from this:

.tran 1s

to this:

.tran 0 1s 0 1u

then the output signal shows a strong oscillation.

?

The problem is that SPICE/LTspice is a discrete time simulator.? It does not simulate in continuous time.? It chooses timesteps based on what is already happening in the circuit.? If it is not oscillating yet, then the timesteps might be too far apart, to get it oscillating.? And then it never knows to make the timesteps smaller, which might be needed in order for it to oscillate.

?

Andy

?

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I try to simulate a testofon, but it doesn't work. Has anyone an idea, why?

/g/LTspice/files/Temp/Testofon.zip

Add "startup" to the .TRAN directive.

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The circuit does require quite a high GBW. With the 4562, it begins to lose gain above 50 kHz peak frequency.

I forgot to mention -

?

I also uploaded "Pease MFB BP filter with UnivOpAmp2.zip" to the Temp folder.? It substitutes the UniversalOpAmp2 in place of the LM4562, and it moves the "OUT" node to the right place.

?

I see that John has also updated his file again, to move the "OUT" node to where it should be.

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His schematic kept the LM4562, so you can compare it against the UniversalOpAmp2 in mine.

?

Andy

?

?

.tran 1s

.tran 0 1s 0 1u

1. You must remember to also add a ".lib" command to the schematic to load the necessary library file.
2. The actual subcircuit names of the UniversalOpAmp* models are "level1", "level2", "level3a", "level3b", and "level4".

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That's what I have now done, but I had strange difficulty in getting rid of the .ASC with the wrong OUT flag.

I agree, a fixed schematic is best.? It would be even better if John had moved the "OUT" node name to the right place.? Oh well.

?

But it really was trivial to delete the ".inc" command and the op-amp symbol, and place a new UniversalOpAmp2 symbol in its place.? That's three steps, and done.? For me, I did not find it harder (in fact it's easier) than editing the name next to the op-amp symbol, and it is much easier than also adding the parameters on the other three Attribute lines if they are needed for it to work right.? Still, some are unaware of the UniversalOpAmp* components and how they work.

?

Analog Devices did mess things up quite a bit by splitting the UniversalOpAmp component into seven distinct components, which now cause confusion when users try using them for the first time and discover that they might not behave like op-amps do.? They should have left it alone.

?

Andy

?

?

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I've updated to include the 4562 model file.

I was suggesting that,as in this case a device include is missing (happens often), if I could comment out the ".inc LM4562_NS.sub", and supposing I had many opamps that use that model, It would be nice not to have to cut and replace those with a new placement of? UniversalOpAmp2, just replacing the names could be made sufficient (ADI change required).

?

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LOL! Not the same as 'simply change the name'.?

Well, you would have already known that it was not possible to simply do that because you already had to point to the LM4562_NS.sub (or whatever) model file. The universalopamp is no different to any other opamp you might choose to use: LTspice needs to know which model file to use. In that respect, it is the same as any other opamp that happens to use the opamp2 symbol, which is presumably what you're using.

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I made a ZIP with UniversalOpamp, but Tony seems to have made it superfluous.? I will upload it, if it still has value.

Hi John, Could you update your zip of the circuit to .inc LM4562_NS.sub?Btw, it occurs to me because of this that a nice feature for LTspice would be to be able to simply change the opamp name on the schematic to UniversalOpAmp to avoid having to place it.

?

Tim

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Could you update your zip of the circuit to .inc LM4562_NS.sub?Btw, it occurs to me because of this that a nice feature for LTspice would be to be able to simply change the opamp name on the schematic to UniversalOpAmp to avoid having to place it.

Actually, you can already do exactly that.

1. Place opamp2 symbol (if not already present)
2. Change the Value to level2
3. Add: .lib universalopamp2.lib as a SPICE directive

You're done!

Of course, if you want to change any of the parameters, that's a pain, because you'll have to look them up. But if the defaults (already defined in universalopamp.lib) are OK, then there's nothing left to do.

The Universalopamp symbols are exactly the same as the opamp2 symbol, but have the various parameters already defined for easy editing. It shouldn't be such a big deal.

IMHO, ADI screwed up the original UniversalOpamp concept when they split all the different versions into their own entities, each with their own separate symbol and the own model files.

--
Regards,
Tony