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Diode isolator for multiple PSUs

Wow
Like....wow.
This video should be posted as a public service to anyone that might own one of these things.
I used to own a x force 400-12 base amp with a linear power supply
that was built back when Carl owned the company.
It was nothing like that.
Not even close.
I don't know who he sold to but that is scary.
Who is building these things now?
 
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LC,

That video seriously gave me a migraine.... that's the worst thing I've seen in a long time... and I've seen some crazy stuff in my years of doing tech work. The 2x8 amp I'm working on is pretty bad also, but nothing like that 200A PSU.


I talked to John at Mega Watt directly about diode isolation, and he told me that if I'm running 5 supplies, to get them as close as I can to the exact voltage, and just parallel them all together. The 12V wires coming off the power supplies must be the same length, and tie to the same feedpoint on the amp board with their respective polarities. He also told me that you only do diode isolation if running just 2 supplies. For the record, I currently have 4 supplies, with a 5th on the way, and all 4 supplies are set at EXACTLY 13.80V. They're all matched to .0x of a volt.

He also said the hissing sound is caused by the switcher mosfets in each supply running at slightly different frequencies, since no single supply will run the exact same frequency as another.

So apparently, in the case of 5 supplies, I don't need to run diode isolation. Now you know. :LOL:


~Cheers~
 
I think the supplies are well made. But switching supplies are like our next generation of phone pokers. A regulated supply will be stable and dependable(heavy), The switchers fight and power(amp) down to protect themselves.

Simply not the case. Parallel linking switch modes has been done for decades. We used to do it in sit down video game cabinets such as Afterburner back in the 1980s.

Link the 0V lines so they're all sharing the same 0V level.
 
Copy. Thank you for your input across the pond. I have tried to use simple equipment to measure their output. DC clamp and so forth. I do think that I could shunt bar them to get a more accurate measurement. 150 amps is not a readily available size. The amp gauges are cheap. So here we go on another adventure. Thanks again for your reply KM6SIL 73's. PS Afterburner and Hydro Thunder were 2 of my favorites. Nice work.
 
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exit,
just for funsies, have a look at this video of a similar power supply that Mike did:

LC

I'm guessing he is not an X-Force fan. The author points out many valid issues but also exaggerates others considerably, while possibly misunderstanding one completely. The single control voltage adjustment should be investigated a bit more before condemning it. I wondered how the builder got one control to run multiple power supplies as it was being described and before seeing the inside. After seeing that one brown wire going into each supply from the single pot, it became clear to me. I'll bet each individual voltage pot is still functional and that brown wire is just pulling one end of all the pots, closer to ground. Retaining individual balance with single adjustment of voltage.
 
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Well, I do know that the supplies are not happy running in parallel... they make a hissing sound and it makes the amp do some weird things, too. Any suggestions on what I can do to remedy that problem?


~Cheers~
On an industry standard - ground 12V supply the load sensing is on the negative lead normally. If you look at master slave designed units this is what you see plus a jumper to set them as master or slave. Usually a system of resistors to supply a constant load is sufficient. I too thought a diode was a requirement but I learn something new everyday. I am a hobbyist not a professional!
 

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