Dual CGS PSUs

monokinetic · Joined: Aug 01, 2006 Posts: 100 Location: prague

Hi,
I'm slowly speccing my new modular with all the lovely info here (thanks a lot!) and I am a bit unsure about the power supply. I've built a GSSL using a toroidal transformer, so I'm roughly familiar with the concepts. But seeing as there's mains involved here, I would just like to double check:

As suggested by Ken, I'm planning on using both the CGS14 and the CGS66 power supplies (one for electrically noisy modules, one for cleaner modules). I checked the yahoo group and there is a message that suggests it's ok to run multiple PSU boards from one toroidal transformer. Assuming I am careful with the amount of amps I'm drawing, is it OK to hook both PSU boards to one toroidal transformer?

TIA

Dave mK

synthmonger · Posted: Wed Feb 18, 2009 2:40 pm Post subject:

That's a good question.

I have a PSU question that I'd like answered too.

I was thinking of how to power a large cabinet with 12 3U sections that requires, let's say 6Amps. Would it be worthwhile to power everything from a huge PSU or have one PSU per 3U section?

If I had to use one PSU per section with their own torroids/transformers would it possible to hook all of them up to a single fuse and power cord? I'd hate to have to use a power switch per section.

andrewF · Posted: Wed Feb 18, 2009 3:59 pm Post subject:

Within current ratings, multiple PCBs per transformer is okay, best to give each PCB its own set of fuses.

It is also okay to have one power cord wired to multiple transformers. One of my modulars has 4 transformers set up like this, has been running a few years without problems, again each PCB gets its own set of fuses. Make sure the housing of each trannie is earthed.

As for building a high current PSU, I have tried to do this a few times, when things go wrong it can be spectacular. If you are hooking up a new untested module...and there is a short somewhere, expect it to get a 5A or so jolt before your 10 Ohm resistors on the inputs burn out. Plenty enough current to blow chips apart. CA3080s are particularly good at this, just these 8 little legs get left on the board...a clean launch!

It is MUCH easier to just have multiple 1A power supply PCBs and you can keep expanding as necessary.

synthmonger · Posted: Thu Feb 19, 2009 8:27 pm Post subject:

monokinetic · Joined: Aug 01, 2006 Posts: 100 Location: prague

Thanks andrewF, that's great info.

Dave mK