Mastero MK-4.5 250w 12v DC-DC ATX PSU + SDC

Mastero · 06-19-2004, 02:03 PM

Hello Friends.

MK-4.5 is comming soon....

Specification:~

Input

8vdc ~ 30vdc (Can survive a Diesel motor start)

Output

+5vdc @ 12A (max)

+3.3vdc @ 12A (max)

+12vdc @ 10A (max)

+5vstby @ 5A (max)

-5v @ 500MA (max)

-12v @ 500MA (max)

PCB Size: 170mm x 110mm (wont fit standard atx psu case)

Built in shut down controller.

Shall post details soon..

Cheers
Mastero

rando · 06-19-2004, 02:48 PM

Sounds interesting. Keep up the good work!

Quattro · 06-19-2004, 04:54 PM

250 watts sound impressive. Do you know what the cost might be?

MatrixPC · 06-19-2004, 05:36 PM

Dam 250W that is impressive

good work

Quattro · 06-27-2004, 03:50 PM

Mastero,
Just wondering if you had any updates on the MK-4.5

MrPerfectionest · 06-27-2004, 10:01 PM

Is this gonna be another brute force attempt?

By the time you get to a 400W supply the heatsink will need to be about 1 ft x 1ft

Mastero · 06-28-2004, 08:10 AM

Quote: Originally Posted by MrPerfectionest

Is this gonna be another brute force attempt?

By the time you get to a 400W supply the heatsink will need to be about 1 ft x 1ft

No there will not be a 400w supply ....

It shall be a while before testing....about a week or two...

Mastero

Quattro · 06-28-2004, 01:17 PM

Thanks for the update. I'm just wating to buy a power supply ans a gps receiver before I start the installation.

owenjh · 06-28-2004, 01:20 PM

Wow, nice specifications, how is the shutdown controller going to work? will it be PIC based? also, how will this be avaliable? thru a kit or just schematic?
Keep up the good work!

MatrixPC · 06-28-2004, 02:19 PM

Mastero, just a suggestion for the next PSU.
Can you add another component to the PSU that can send a pulse to turn on the PC. Right now we depend on the mobo that "Resume on power loss" for turn on. Most mobos have that option but there are some mobos don't have that option.
I found the circuit from the12volt.com that use a relay, cap and resistor for constant to pulse.

- Output of the Sproggy relay connect to Pin 86 on image (relay coil +).
- Ground connect to the cap and resistor then to Pin 85 on image (relay coil -) .
- 2 terminal of the ATX power sw can be connected to pin 87 and 30 on image (SPST-NO) pin of the relay.

I tested that circuit on my mobo and it work very well.

Mastero · 06-28-2004, 06:14 PM

Matrix i know this cuircut .... i have also tried it works great.

Let me see if i can add a startup also ...

Mastero

rando · 06-28-2004, 06:29 PM

Cool, it's always good to see you considering more features Mastero. You the man!

BTW, if you use the ignition/ACC signal for the switched +12v lead then wont this circuit send a pulse every time the key is switch from off to on (even if the computer is already on)? Suppose you have a large shutdown delay to keep your pc running during stops at a gas station. When jump back in and restart your car, your computer is going to receive a pulse and start to shut down, isn't it?

Cris · 06-28-2004, 07:23 PM

How much heat is that PSU going to dissipate?

MatrixPC · 06-29-2004, 12:32 AM

Rando, that is true. Everytime you have the IGN/ACC line come hot the circuit send a pulse. That is why on the bottom of my previous post I stated that the (+) to the relay coil is connect to the Sproggy relay output.
Now this got me think more that could also be wrong since the Sproggy relay won't turn on until the power button is "pushed".
The correct place to connect to is the the relay where the output is going to the 5V standby regulator (base on MK4.0) The SDC circuit switch on the relay (STBY Relay) to put the PSU in standby mode thru a 5V regulator chip. The output of the (STBY relay) can connect to the (+) coil of this "power on" relay.
Ok now it should work.

rando · 06-29-2004, 12:59 AM

Oops, I didn't notice the latter part of your post. With the changes you posted, it makes sense now. Also, it seems like you might be able to ditch the relay in favor of a much smaller and cheaper switching transistor. Small, cheap, powerful and efficient ... it's going to get there!