Help to pick 28v PSU?

[Steve]

Hi guys,

I'm wanting to replace my Apple G4 Cube PSU internals with a more modern, cooler running PSU (more efficient etc) The current one is getting long in the tooth and runs quite hot as a fan less design of its age.

FYI a blog of someone doing the same thing:
http://www.edretrotech.com/2021/02/powe ... upply.html

Now I'd rather not buy some cheap chod from China that might be unrated and explode in to flames like he did... But I'm not as clued up on others on here when it comes to decent PSUs.

What I need: 28V and ideally no more than 4amps (the original is 200watt 7-8amps, but the cube itself only needs max 2.5amps)

Two I found:
https://www.mouser.co.uk/ProductDetail/ ... 2BIA%3D%3D
https://www.mouser.co.uk/ProductDetail/ ... OTPGAfuw==

[Steve]

Top one is too powerful to be honest and the second one looks very small, so I'm not sure if it would be up to the task. Any advice appreciated, thank you.

[PhilC]

@Steve I know they are Chinese but do check out and see if some of the MeanWell range will do what you want. I've used 5 or 6 now and both my 3d printers also have their PSUs, no complaints here so far.

[exxos]

As philc says, meanwell seems to be popular and good specs. I'd look at the ripple and noise figures .. Lower the better normally. PSUs should easily be able to manage 50mv noise levels these days.

China PSUs,who knows. I need to do some long term tests for possible sub's for on the remake boards at some point.

[Steve]

I had a look at Meanwell and it seems they don't exactly do 28v in their entire range, closest I found is 27v. I would assume this may be well out of the voltage tolerance and send all the voltage divisions out of whack?

[exxos]

Hack it ;)

[rubber_jonnie]

There are a couple of Meanwell PSUs that will do 28V and are adjustable up to 29V, but I don't know if the overall power rating is suitable, have a look for the PSC-100B and PSC-60B.

[Steve]

Cheers for the link @rubber_jonnie

I found the 150watt version:
https://www.meanwell-web.com/content/fi ... 5-spec.pdf

Seems alright. Do the specs look half decent to you guys?

[rubber_jonnie]

No worries. I'm not really familiar with those Macs, but as long as the power output is at least as good as the original you should be fine