Thanks for letting me know about the other channel, it was in Japanese, but I should have done the decent thing and waved Google Translate over it, apologies.

I've keyed your schematic into PSUD2 and I'm getting exactly the same results. I tried it in (the unreleased) PSUD3 and it's giving 10V more and a "thump" at the start. So there's a problem in PSUD2. If you simulate PSUD2 for about 10-20mS it shows a substantial amount of dithering so the simplified model is getting confused.

Here's what PSUD3 shows:



Here's the bump at the start in more detail:



By increasing the transformer off-load voltage to 260V which is a typical value (base + 8%) it will give 257-258V output. However, the results are still low on PSUD2, here's the dithering at the start of the simulation I mentioned earlier - a sure sign that it's struggling to do the calculations:



Conclusion: PSUD2 has some holes in the simulator and they are showing up on the schematic you keyed in. There's no bug fix that I can apply as the PSUD2 simulator engine is broken as designed. I'll put a beta of PSUD3 out on here about 2nd / 3rd week in August; being a beta it will probably have a few issues of it's own but at least it's accurate and any issues that are found should be fixable.

Regards,
Duncan

Thanks for the clarification regarding off-load voltage and rated voltage.

About the current draw... the schematic is for a stereo amp so I estimated around 96mA for two 6V6 and two EF86. The arrow at the node that reads 258V translates as "To other channels."

That said, maybe I'm reading the schematic wrong and the 258V reflects only that one side of the amp... but wouldn't you model the entire current draw (all tubes) on the power supply?

If you right-click on the rectifer area when it is lit up, it should allow you some different choices.

Regards,
Duncan

I can see a couple of potential issues:

1. The transformer voltage should be the off-load voltage rather than the rated voltage. If you can't find out from the transformer manufacturer, try taking the rated voltage of 240V and adding around 5%-8%
2. I think 96mA is a very high current draw for a single 6V6 and an EF86, I would be inclined to go for around 50mA in the absence of solid data

Try those and see if the results end up being closer to what you expect.

Regards,
Duncan

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I do not understand how to change the default bridge rectifier to a
full wave. Trying to get my first PSU designed

Roger

Hello

Thanks to group members answering my previous Q - adding sections and solved by tapping on a Mac trackpad (!)? Yep, I had no idea.

However, and having reviewed the available documentation on PSUD2, that I can find, anyway, I'm still in a quandary about what to 'look out for' and how to actually i.e. practically go about designing a 'good' 'good enough' PSU??

For instance, although it's a simple task for me to measure primary and secondary winding resistances, I do not know the % regulation of my Trafo.? Nor do I understand the application or function of 'current taps.'? Is my 'final' load - 5kΩ or 86.5mA (the combined load of a 300B and a 6N8S / 6H8C?? To me all these things are still mysteries.

has helped me, a little, thanks DHTROB, but maybe I''m just not 'clever enough' or cut out for this kind of thing and perhaps there may be other people in similar difficulty?


?

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In the corporate world, I suffered with McAfee, Norton, AVG.

As a developer, fewer install problems from MalwareBytes using customers, but that could be due to market penetration.

MalwareBytes outshines all the others on our personal machines. First used in the early '00's.
IMO, the best support when needed, the least intrusive, plays well w almost installers.
AND group pricing for several PCs, not a separate license for laptops and desktops

- Ian

Not to sound like a shill for Malware Bytes, but I've been using them for years, first the free version and then the paid version
It seems to work well and doesn't seem to interfere with my downloads
Andy

Thank you for the reply.? For others who might be interested: turning off McAfee to install does work and the program works.? Until McAfee resumes.? Then it kills the program requiring a new download and install.

Apologies, I was about to reply but you have summed it up nicely Paul.

Yes, for a few years MS throws an error message when installing uncertified software. I'll sort out the Microsoft certification and code signing bit in the fullness of time, there are quite a few hoops to jump through:?

My own experience with AV software on Windows hasn't been great; AVG and McAfee have hit me with a number of false positives in previous years so I just use the Microsoft Defender that's built into Windows these days. However, it's a matter of what your comfortable with.

Regards,
Duncan

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since updating my computer, the new download of spud doesn't work.? McAfee blocks it.? Tried on two computers.? On one it says incompatible.? On the other McAfee stops it.? The download worked fine.? Opening the app doesn't.

Duncan may be busy. I done some software support and know the usual questions.

What version of Windows? 7, 8, 10, 12?

"incompatible" MAY just mean that Duncan has not paid Microsoft to be developer certified. This is mostly about MS being monopolistic. There may be a way to tick-off "run anyway".

As for McAfee... &^%$#@! It was a good idea 20+ years ago. But now McAfee seems to cause more problems than cures. Between the software with Duncan's own name on it, and software from a marketing machine who took-over from a madman, _I_ would turn-off the McAfee for long enough to install PSUD.

First post here: since updating my computer, the new download of spud doesn't work.? McAfee blocks it.? Tried on two computers.? On one it says incompatible.? On the other McAfee stops it.? The download worked fine.? Opening the app doesn't.? Any suggestions?
thank you\
les

Hi,

You're going to need to give a bit more information. Did it:

• Fail to download - please provide the link you used for the download
• Downloaded but failed to install
• Installed but failed to run
• Ran but didn't work correctly

Also if you could tell me which operating system you have, that would be a help too.

Regards,
Duncan

Hi Jay,

Go to the website?/g/duncanampspsud?then down the left side, you will see the files area. Click on that, then click on the link for psud2_windows. Click on the build76 file and it will download for you.

Regards,
Duncan

Hi Chris,

Something similar came up a couple of years ago, it involves a slight tweak to the MacOS settings. There's an article on it here that shows the exact same problem, and then further down, how to fix it.?/g/duncanampspsud/topic/77707176#16

Regards,
Duncan