Got my Mac mini this morning! - Read my first impressions...

**gork** · 01-22-2005, 02:51 PM

Originally Posted by NiN^_^NiN

Well if you guys remember my post i said that on the MB of the mini mac there was only 2 traces from the power supply a + and - and if the plug can work nomatter what way it's turned around then it supports the theory i have about it being 1 voltage which is good

The available photos are not enough to substantiate that theory. Even if you really could differentiate the traces in the photo, the PCB is probably 4 layers at minimum. Usually on a board like this, you have an entire layer dedicated to GND and an entire layer dedicated to each voltage (3.3v, 5v, etc.. whatever you need.) The plug has 10 seperate pins and while I really hope it's a single voltage supply, I will put a voltmeter to them on Monday morning when I get back to the office to be sure.

Originally Posted by NiN^_^NiN

If it did use more than one voltage then flipping the plug is impossible in theory think about how the figure 8 plugs work 1 voltage but don't need to be plugged in a specific way i'm 100% sure it's 1 voltage as the plug and the actualy mb proves it to me

Well... wrong again. Have a look at how you can make a reversable 10 pin connector with 4 voltages. I have numbered the 10 pins 1-5. Pins of the same number will carry the same voltage in either orientation:

Code:

 1 ]=[ 2
 3 ]=[ 4
 5 ]=[ 5
 4 ]=[ 3
 2 ]=[ 1

It's also worth noting that being an 85W supply, it would be counter productive to have it stupidly supply power all the time. Some of the pins may actually be some kind of signalling from the computer to the PSU to power up/down. This type of signalling is not that uncommon with power supplies... I even have a desk phone with a wall wart that has a PFI pin that must be pulled high for the unit to supply a significant amount of current. I discovered this when the power brick failed and I tried to replace it with something generic.

The G4 cube had a single voltage supply (24V) and the VRM board that regulated this down to 12/5/3.3 was a frequent cause of failures. It also introduced a significantly larger amount of heat into the design. It's reasonable to assume that Apple would not want to make this mistake again. I stand by my assessment that the PSU will be a huge stumbling block on the road to in-car use of the Mini. Hopefully, I'm wrong. Hopefully, even if it is so problematic, there is enough interest and buzz for someone to make an aftermarket DC/DC power supply even if the hobbiest community does not jump to the task.

Originally Posted by NiN^_^NiN

It looks like all you would need is a laptop adapter for the car and get a shutdown controller or you could have a small relay which pushes the power button and then a timmer which cutys power in 1min after engine shutoff etc.

Yes, hopefully so.

Originally Posted by NiN^_^NiN

but the software is where we should concentrate first I think as im sure the hardware is easily adapted to car enviroment

I don't know why i keep comming to a mac forum when i will never buy it and don't even use macs :P but i like to help

I will leave others to focus on the software and I will poke around at the hardware

Thanks for your interest, though.

**MikeH** · 01-22-2005, 03:09 PM

The CarNetix P1900 (to be renamed i1900

) is fully compatible with the 18.5V 4.6A power requirement of the Mac Mini. It is currently in beta testing. I picked my mini up about 1 hour ago. Will report what I find about power sequencing.

**gork** · 01-22-2005, 03:12 PM

Wow your PSU's look really awesome. Glad to hear that someone that makes PSU's also actually *has* a mac mini now!

**MikeH** · 01-22-2005, 03:56 PM

I've been designing computer stuff since the Intel 4004 (long ago). This my FIRST MAC! Very cute! Hopefully the rumors are true about an ACPI-like header inside. I'm a bit reluctant to pop mine open. I do know the power connector provides a single +18V/4.6A output on mutiple pins to spread the current (very common). Also, the power button puts the Mini into sleep instead of shutdown. Restart is nearly instatneous! Does not resume MP3playing from iTunes....?

Looks like the perfect CarMac.

**MikeH** · 01-22-2005, 04:09 PM

gork,

Can you post your disassembly process (ie where did you pry with what and how bad does it look after you did..?). Any pictures?

**emailthis1** · 01-22-2005, 04:25 PM

Here is a link to a video showing how to pop open a mac mini. http://www.smashsworld.com/2005/01/t...ini-how-to.php

**MikeH** · 01-22-2005, 04:50 PM

Got it! Thanks!

THERE IS a 2-pin ACPI-like jumper!!

**NiN^_^NiN** · 01-23-2005, 12:36 AM

Originally Posted by gork

The available photos are not enough to substantiate that theory. Even if you really could differentiate the traces in the photo, the PCB is probably 4 layers at minimum. Usually on a board like this, you have an entire layer dedicated to GND and an entire layer dedicated to each voltage (3.3v, 5v, etc.. whatever you need.) The plug has 10 seperate pins and while I really hope it's a single voltage supply, I will put a voltmeter to them on Monday morning when I get back to the office to be sure.

If you look you can see that the PCB has the 2 prongs for the power plug go through the board that means it is 1 voltage :

MIKEH was kind enough to check the psu and backup my claim

besides there are chips on the board that convert the power so u can see why i was 100% sure

Originally Posted by gork

Well... wrong again. Have a look at how you can make a reversable 10 pin connector with 4 voltages. I have numbered the 10 pins 1-5. Pins of the same number will carry the same voltage in either orientation:

Code:

 1 ]=[ 2
 3 ]=[ 4
 5 ]=[ 5
 4 ]=[ 3
 2 ]=[ 1

This is true u could make it more than 1 voltage but as i said it isn't.

Originally Posted by gork

It's also worth noting that being an 85W supply, it would be counter productive to have it stupidly supply power all the time. Some of the pins may actually be some kind of signalling from the computer to the PSU to power up/down. This type of signalling is not that uncommon with power supplies... I even have a desk phone with a wall wart that has a PFI pin that must be pulled high for the unit to supply a significant amount of current. I discovered this when the power brick failed and I tried to replace it with something generic.

Well most motherboards use a small current to detect the soft push button which leads me to believe that this is the same altho i could be wrong

Originally Posted by gork

The G4 cube had a single voltage supply (24V) and the VRM board that regulated this down to 12/5/3.3 was a frequent cause of failures. It also introduced a significantly larger amount of heat into the design. It's reasonable to assume that Apple would not want to make this mistake again. I stand by my assessment that the PSU will be a huge stumbling block on the road to in-car use of the Mini. Hopefully, I'm wrong. Hopefully, even if it is so problematic, there is enough interest and buzz for someone to make an aftermarket DC/DC power supply even if the hobbiest community does not jump to the task.

They just designed this better in this new mac no biggie as i sayed 1 voltage which is good for car enviroment

MikeH has the power requirments and is already adapting the power for it.

The software is where we should concentrat and let professionals like mike work out the hardware

altho if u wanna make your own then your most welcome to but cause the power requirment of this mac it prob be better to just buy the psu off MikeH

I just looked at the macmini here in aus it's $799 for the basic model none of the airport etc added so screw that

its as much as my LCD screen

But i wish all u mac users luck

**MikeH** · 01-23-2005, 07:09 AM

MikeH has the power requirments and is already adapting the power for it.

Yes....we are desperately trying to find the connectors listed below so that you don't have to hack up your brick to make this work. If anyone can identify a source of these power & ACPI connectors please let me know.

**agentofchange** · 02-06-2005, 09:47 AM

Originally Posted by NiN^_^NiN

It looks like all you would need is a laptop adapter for the car and get a shutdown controller or you could have a small relay which pushes the power button and then a timmer which cutys power in 1min after engine shutoff etc.

http://www.welovemacs.com/usbpoonsw.html

USB Start-Up Key for Mac (p/n USB-KEY-BT)-Limited Supply

For $15US you can hack up this switch anc wire it into a relay of some kind.

http://www.sophisticated.com/product...y/pkp_650.html

This device is overkill but is scriptable.