[BPT]

Paul:
It's been 10-12 months since I read about the different Mini mods. I don't recall where I read it, either the MP3Car forum, DIY audio or AudioAsylum. At MP3Car.com enthusiasts have been successfully powering there Minis at 12VDC inside their autos since the Mini first came out.
Chris H.

[Paul Hynes]

Hi mintzar,

I'm sure someone will assess the latest version for mods sooner of later.

Hi Chris,

Thanks for this further info. I will have a look on the Net when I find a spare moment.

To everyone else with an interest in upgrading Mac Minis,

Please feel free to post information that may help this project. I will help where I can but as far as I am concerned it is an open source project so let us have your experiences.

Regards
Paul

[mintzar]

Here is a very cheap chinese DIY supply based on the LM317 regulator.

http://cgi.ebay.com/Power-Supply-Board-Kit-PCB-Based-LM317-LM337-IC-/250512862177?cmd=ViewItem&pt=Vintage_Electronics_R2&hash=item3a53baebe1

Obviously replace some of the caps and diodes with some nicer parts, add in a TX, and you have a semi-dandy supply on your hands. Even stock it's probably nicer than the Mac Mini's supply. Low cost, low end alternative to reinventing the wheel so-to-speak.

[mintzar]

I hacked open the Mac Mini power supply. I found a cheap one on ebay that I was going to steal the DC cable off of and figured I'd hack the sucker open. It was a PAIN in the you know what to get that thing open. I had to take a hack saw to get through the plastic. The thing is a tank, you could drop a bowling ball on it a few hundred times and it wouldn't show a scratch.

At any rate, here are some pics:








I am going to desolder the big pieces and take some pictures for you to see a little less cluttered board...

[Paul Hynes]

The mac mini requires step-up conversion to 18v5 to operate from a 12 volt source. As the goal is to reduce the number of switchers this is not an option for the project and the target remains to design a good linear supply for 18v5, either mains or battery.

Regards
Paul

[mintzar]

How do you wire the resistor for the iSense connector? What value resistor is it?


EDIT:

It's a 6.8k resistor.

http://www.mp3car.com/vbulletin/maccar/73847-mac-mini-power-pinouts.html

[Paul Hynes]

Hi mintzar,

A link in the first post on this thread shows the cable wiring diagram and the resistor value.

Regards
Paul

[mintzar]

Finished my Mini PSU the other day. Plugged it in, everything booted fine. Then shuts down after a few minutes. Turns out my Transistor and rectifier don't have a high enough amperage rating and I'm drawing too much current through them. So it's back to the drawing board.

I'll need at least a 10-12A rectifier (any recommendations?). And a higher current regulator. Should have realized the LM317 is too low current.

Any ideas?

[Steve Jones]

Just found this thread.

For my transformer to supply my coming PH reg, I've got setting on my kitchen table this:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=122-620

Although, the ANTEK noted earlier is less expensive. Both should work well, as they are over spec'ed to what Paul recommends.

[Steve Jones]

I'll need at least a 10-12A rectifier (any recommendations?). And a higher current regulator. Should have realized the LM317 is too low current.

Any ideas?

How about a Paul Hynes Design?

[Steve Jones]

At MP3Car.com enthusiasts have been successfully powering there Minis at 12VDC inside their autos since the Mini first came out.
Chris H.

They use a switching DC-DC converter for voltage step up.

[mintzar]

I was able to build my PSU. Made a tremendous upgrade in my system. I used the LM338, which was fine in my system since it can handle 12A peak and 5A nominal.

It's been running for 4 days now. It's an upgrade that anyone running a Mini needs to do.

[TRADERXFAN]

So, being a non-diy type, I am a little lost. I hear great things about the Paul Hynes "brand". But it seems mostly to be parts that go into other equipment.

 Is there going to be a commercial product offered as a drop in replacement for the mac mini power supply? Or is this just a DIY project thread being hosted here?

I would be interested in this product, should it be brought to market.

-Tony

 

[Steve Jones]

Most of us here are really (really) cheap (me-I'm part Scottish), and just buy the working guts of Paul's products, and work it out on our own. That's what makes it fun for us.

He will gladly taylor what you want depending upon the level of your abilities or finish requested. From sending him your equipment for him to modify, to assembled and tested subassemblies for you to add to your kit like us, to turn key external 'black boxes' to power your gear, just ask Paul. He's very flexable.
 

[Steve Jones]

I built my supply for a few people. I am speaking with Clayton Shaw at spatial computer about offering my supply with his spatial systems as an upgrade option. So I imagine it will be available commercially relatively soon.

http://www.youtube.com/watch?v=XZ6N5m8FpVg

[Paul Hynes]

Hi TRADERXFAN,

I do provide a power supply for the Mac Mini and it currently costs £524. The regulator module, which incidentally has a much better specification than the LM338, is called the PR3iHD-18v5 and it costs £120.

I had been intending to provide details of DIY options for the Mac Mini supply but I have been too busy at work recently to do this. Watch this space and it will arrive eventually. 

Regards
Paul

Regards
Paul

[JDUBS]

Paul

Any updates on the DIY options?

Thanks,
Jim

[Paul Hynes]

Hello Jim,

Here is the mains powered option using the PR3iHD-18v5 linear high performance regulator module. I have had some new boards prepared for this and reduced the price of the module to £120 (previous August post altered to reflect this). Insured carriage and packing varies depending on delivery destination and can be quoted on request.

http://i700.photobucket.com/albums/ww7/paulhynes/MM1AN.jpg

Properly applied you can run at up to 6 amps continuous if required although a minimum function audio server using the Mac Mini should draw less than this. The transient current delivery is much higher so this is also a good module choice for loads that draw high transient currents. The usual voltage range options are available with this module.

I will be pleased to help any who have questions regarding application.

Regards
Paul

[JDUBS]

Good stuff.  Thank you, Paul!

-Jim

[Paul Hynes]

For those that still fancy the battery solution for the Mac Mini, with high quality linear regulation you can simply connect two 12 volt, heavy duty car batteries in series, to give some headroom for the regulator, and feed a DC version of the PR3HD-18v5 module to provide the regulated output voltage of 18v5 at up to 6 amps. You will need to mount the regulator module on a large heat sink rated at 0.5 degrees C per watt to keep the temperature of the regulator output mosfet at a reasonable level (roughly 25 to 30 degrees C above ambient temperature worst case with good airflow across the heat sink). You will also need to keep up with the battery charging requirements to ensure long battery life.

Three batteries in series will allow regulation to 30 volts for products like the Virtue Audio amplifiers.

Regards
Paul