The figure shows a circuit with a ±17V dual power supply and a 10W power amplifier.
The AC signal input to the power amplifier is 1Vp-p.
10Vp-p should appear on the output.
However, when looking at it using KiCad’s simulation function, a DC current of about 4mV is output.
If you simulate the same diagram with LTSpice, 10Vp-p will be output.
Doesn’t the circuit diagram drawn on this KiCad have 10Vp-p at the output?
If not, please tell me where the mistake is in the circuit.
Thank you.
Some transistors have 1 at base and some have 3.
Do you use models with different pin order?
Why not separate the things:
Discard the left part (the power supply, which creates an articial ground), and add a V2, both V1 and V2 having 17 V and ground in the middle. Then check if the amplifier is o.k.
Dircard the right part (the amplifier) and check if the power supply is o.k.
If you want me to have a closer look, please post the complete project, including all device models used.
Thank you for your reply.
As I said, the base of the transistor was the transistor where 1 comes, 2SC5200 and 2SA1943.
There were also 3 transistors coming, 2SC3423 and 2SA1360 and 2SC3298 and 2SA1306. The pin order of the transistors in the circuit diagram seems to be correct.
thank you for your reply.
We verify each case separately.
I removed the right part (amplifier) and checked to see if the power supply was normal. It was normal.
I have checked all the device models used and the simulation models seem to be working correctly.
???
Seems or you have checked it by using each transistor in simple circuit where you can easily verify its behavior?
The power supply circuit and 10W power amplifier parts are separated.
For the transistor, I changed the symbol pin and model pin in the 2SC3298 simulation editor.
The simulation results show that the input voltage is accurate, but the output voltage is around 0V.
I would like to get some advice.
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Can you not put probes at various points in the circuit, starting from the input to see how far the signal gets? Just like you would do with a physical amplifier. For example the output pin of the op-amp would be an obvious point to check next.
Thank you for your reply.
I immediately looked at the output voltage of the operational amplifier.
It was 1.5V DC.
As far as I reviewed the circuit diagram, it seems to be correct.
Please let me know if you know the reason.
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But no AC signal there?
I think your op-amp is not amplifying. It’s a nop-amp hahaha.
Simulate the op-amp in a separate cicruit to make sure you understand it. Maybe the model is wrong? Or the pins are wrong? Are you sure the model pins are the same as the IC pins?
Thank you for the advice.
I changed the operational amplifier from NJM5532 to NJM5532DD.
However, when I run the simulation, an error like the one shown in the figure appears. No matter what I do, the error doesn’t go away.
If there is a way to avoid the error, please let me know.
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You should probably do what Holger asked way back in the #3 post, post the project including the models used. Otherwise you’re missing out on his expertise.
First, I removed the power circuit and powered the power amp as Holger suggested.
I then reviewed the simulation model.
I would like to move on, but when I run the simulation I get an error.
First of all, I would like to know how to avoid this error.
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Maybe you don’t understand this phrase. This means zip up your project and model files and attach to your post so that people can try your simulation. That cannot be done with screenshots.
Dear retiredfeline.
Thank you for your reply.
Compress and send the project and model files.
Please take a look.
KiCad_±17V_2.zip (242.7 KB)
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Dear Piotr.
Thank you for your reply.
Compress and send the project and model files.
Please take a look.
KiCad_±17V_2.zip (242.7 KB)
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Dear holger.
Thank you for your reply.
Compress and send the project and model files.
Please take a look.
KiCad_±17V_2.zip (242.7 KB)
1 Like
I spend using Spice in KiCad may be 3 days 3 months ago and simulated circuits containing no more than 5 symbols. From those time I remember: “there are problems with pin orders (even for diode)”. I reported a bug about it.
To see your project is too complicated. I write from Win7 PC where I have KiCad V5 (last Win7 working KiCad version). I have KiCad V7 at PC not connected with internet. As it is ‘for safety’ I’m limiting transferring anything toward that PC (opposite direction is ok).