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ashiekh
07-15-2019, 08:03 PM
LLC seems somewhat recent; why is that? The idea didn't exist till recently or the necessary technology? Or perhaps there was little motivation till the drive for efficiency.

This document mentions it being discussed 3 decades ago https://www.microsemi.com/document-portal/doc_view/129464-understanding-and-using-llc-converters-to-great-advantage

Jon Gerow
07-15-2019, 08:40 PM
LLC seems somewhat recent; why is that? The idea didn't exist till recently or the necessary technology? Or perhaps there was little motivation till the drive for efficiency.

This document mentions it being discussed 3 decades ago https://www.microsemi.com/document-portal/doc_view/129464-understanding-and-using-llc-converters-to-great-advantage

It was always available, but without efficiency requirements, never really necessary.

When I first used it in 2007, it was the only desktop PSU to have it. And I could only get the (very expensive) NXP controller in any kind of volume. When that volume dried up when I was ready to "revamp" the product, essentially doubling our forecast (as we weren't discontinuing the previous, just adding another model), I found out the lead time on the NXP controller was very long!

Now-a-days, more companies are making LLC controllers and they're much cheaper. Champion, Infineon.. they're all making LLC controllers among others.

Stefan Payne
07-15-2019, 11:21 PM
LLC seems somewhat recent; why is that? The idea didn't exist till recently or the necessary technology? Or perhaps there was little motivation till the drive for efficiency.

This document mentions it being discussed 3 decades ago https://www.microsemi.com/document-portal/doc_view/129464-understanding-and-using-llc-converters-to-great-advantage
Later Versions of the Playstation 3 had an LLC-Resonant mode PSU or what looked like it.

The Reasons are the usual:
a) cost
b) no need
c) proven alternatives

Another Problem with LLC is that its a single voltage converter, Double Forward can be a multi Voltage Converter (ie: one Voltage in, multiple come out).
So for a PC you need something to convert 12V to 3,3V and 5V, you need Controllers to control that.
And that might just not have been there...

The NMB WTX PSU I have from the early 2000s for example use a PIC16 and some weird stuff...
Sadly I don't have access to some pix of that...
That might have been/could be an LLC Resonant mode PSU...

So they were just not that common at the time because you didn't need the advantages of an LLC Resonant converter.

ashiekh
07-16-2019, 12:12 AM
I assume any patents have expired

Stefan Payne
07-16-2019, 01:39 AM
I assume any patents have expired
FRAND???

Batboy88
08-20-2019, 06:17 AM
try to go like reallll low maybe like 11.4v man...and this massive 10v cap.