I am creating a schematic for a power supply. I added PWR_FLAGs to all of my power connections, which seems to have satisfied ERC, but I am puzzled as to why what looks like an AC source to me has an “Electrical Type” (which cannot be changed) of “Power input”. I used the “0V reference potential for simulation” for my GND, but find that it has no simulation properties (2 error messages appear when I try to open them). I have read the excellent (and often cited) StackExchange post, but still fail to understand what I have done wrong and what I should do otherwise. ERC now shows no violations, but complains::
a) “Schematic is not fully annotated.”
b) "SPICE model issue*
How can I find the causes of these complaints?
I would upload the schematic if I could (it is only 60kB), but am not permitted to do so as a new user.
I would upload the schematic if I could (it is only 60kB), but am not permitted to do so as a new user.
Read and follow New Member Information and promote yourself to basic user level.
To upload a project use kicad-manager–>File–>Archive project and attach the resulting zip-file. You could delete the internal backup-folder from the zip-file prior to uploading.
error “Schematic is not fully annotated”
Every individual item (symbol) needs a unique reference designator. The reference-designator consists of a starting string and has always end with a number.
This requirement is not fulfilled if you see the “Schematic is not fully annotated” error. You can either search for the symbol with missing/false/doubled annotation or simply use the annotation command: main menu bar–>Tools–>Annotate schematic
additional remark: always mention the used kicad version in your question. There are currently at least 4 different versions in real use and the answer to a problem is depending (more or less) on the kicad version.
Many thanks for your quick and informative answer!
It looks as though I have achieved Basic level, so I am attaching the archive you suggested:
BipolarCharger.zip (10.6 KB)
I didn’t recognize “kicad-manager”, but I found the Archive command in the File menu of “KiCad 7.0” (kicad.exe), which I am running under Windows 10 22H2. I didn’t find a backup folder in the resulting zipfile, although there is one in my project directory.
The warning “Schematic is not fully annotated” was apparently due to my attempt to use the Reference field to label my AC source “9V” (since the Value of “AC” cannot be changed). It has now been automatically replaced by “#9V0101”, which makes ERC (but not me) happy.
Any tips on how to identify the source of my “SPICE model issue” would be greatly appreciated.
At a first glance the attached archive looks good.
Regarding the simulation/spice issue you will need help from others - that’s not my core competence.
(for pure simulation of this circuit I would start with removing the switch - simulating a manually pushed switch will probably not work)
Thanks for the additional tips. One thing still confuses me about the schematic library. The AC symbol that I used is indicated in its Simulation Model as a “Voltage Source”. Why then is the Electrical Type “Power input”, requiring the use of a PWR_FLAG?
The pin type and also the ERC are independant from the simulation.
Evidently. But why does the AC voltage source in the included library have what, according to the FAQ topic, is the wrong pin type?
What is the appropriate way to deal with this? Should I open an issue on GitHub? If so, which of the many KiCad repositories would be the appropriate one?
Meanwhile I figured out how to make a copy in a new symbol library and change the Electrical Type of the pin of the copy. However, before I start using non-standard components in my schematic, I want to get the simulation working. Since this appears to be a separate issue, I will first read up on ngspice and then start a new thread with the “Simulation (ngspice)” tag. Thanks for your help.
Your AC symbol is just that: a symbol. It’s got nothing to do with simulation and you can’t supply “one-pin” power. You always need two leads.
The correct sources are found in the “Simulation_SPICE” library, in this case “VSIN”.
A comment: your circuit will very likely oscillate in the 10s to 100s MHz range. See what the simulation says. And the Q2, Q4 symbols don’t match.
Thanks for the tips! I was wonder why the AC voltage source only had one pin!
Since most of the symbols I found already had simulation models, it never occurred to me to look for a special simulation library.
Thanks for pointing out my mistake with Q4. I have simplified the schematic, eliminating components without simulation models, but still get “SPICE model issue*. How can I find out what KiCad is complaining about?
Despite this, I am still able to run simulations (which don’t show any oscillations).
They did reveal that I was mistaken in assuming that the AC voltage parameter was really AC (RMS) voltage, when it is apparently P-P voltage instead. In the simulation model of VSIN, it wasn’t clear to me whether “Amplitude” or AC magnitude” was the correct parameter to use, so I started by entering the same value in both. A little experimentation suggests that “Amplitude” is what the simulation uses.
The simulations provided the information I was looking for to tweak some component values. I have found a SPICE model for the NPN transistor I am using, but don’t know how to apply it to the transistors (Q2 & Q4) in the schematic, since the schematic editor doesn’t appear to support .mod files for simulation models. For the time being, I just adjusted the beta values.
The AC source in my case is a “wall wart” plug-in transformer rated at 9V. Of course, the actual output voltage depends on the load applied. Is there some way to include the current rating (2A) in the simulation to get an idea of what the actual voltage would look like?
P.S: I am attaching the updated project.
BipolarCharger.zip (10.1 KB)
I get no errors, neither from ERC nor simulation, and a quick sim shows an expected result.
The amplitude value for VSIN is peak voltage, in your case 15 V. Peak-peak would be 30 V.
AC magniture is irrelevant here.
You can use .mod files, just rename them to .lib.
I won’t say much about the schematic simulation interface in V7, except that it’s a disaster. Last time I said the same, I got bucket of manure over my head from the developer, so be careful. Suggestions NOT welcome.
Sorry, I meant to say peak, not P-P. IAC, not RMS.
The SPICE issue is a warning (on second tab of ERC results), not an error (screenshot attached).
I confess to having had trouble getting up to speed with the simulation integration, but I am happy to have any integration at all!
It has been at least 35 years since I last used SPICE!
Many thanks for your help!
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