5V and 12V POL anyone?

**MatrixPC** · 08-01-2006, 05:41 PM

Well, my setup in the Matrix sucking up so much juice on the 5V rail that the DVD ROM can't really play. The DSATX can't keep up with the demand. I just play with the datasheet and the old sproggy design and come up with a 5V and 12V POL. Actually I only need 5V to aid the DSATX, but the rear seat passenger video screens I have use 12V and I don't want to take any more juice out of the DSATS 12V rail (althought I think I still have lots of juice left), so may as well draw a 12V POL too.

The 5V POL on this PCB is base on Maxim Dallas MAX787 5.0V chip. I have this chip when I did the sproggy PSU.

The 12V POL is base on the sproggy 4.X design and base on National Semi LM2587T-ADJ and LM1084-12 chips. I test it with 55W H3 bulb without any problem. This 12V is power both of my setup before I get the DSATX as beta.

**MatrixPC** · 08-01-2006, 05:44 PM

In this one, both 5V and 12V are base on National Semi chips.
The 5V POL is base on National Semi LM2678-5. The only different between this chip and the Maxim chip is that different inductor 22uH vs 47uH. This design was use in the 5V rail for the Proggy 4.0 (I think).

The 12V is the same as the previous post.

If there is interest, I will upload the PCB (pdf) for both.
Don't ask me to make one and sale. I don't have a tool and time to do it. You have to get all the part and etch your own PCB.

**tj!2k4** · 08-01-2006, 05:51 PM

cool, gonna keep an eye on this. do you plan on "mass" producing these? if so, I'd be interested in the one that does both 12&5v.

**MatrixPC** · 08-01-2006, 05:55 PM

Okay, I can only take credit for spending time with expressPCB. The design are base on Mastero and/or Sproggy.

Don't blame me, mastero or sproggy if you screw up.
Don't ask me more technical stuff than what in the datasheet. I am not an EE guy to ask these stuff. It just happen I can read the datasheet and familiar with expressPCB

.
The design is provent to work cuz I all ready make one for myself. By that, it doesn't mean it will work for you (well it should work). I will upload some pic when I get home.

PCB size
5V & 12V: 1.6H(40.65) X 3.67W(93.25)
5V: 1.6H(40.65) X 1.12W(53.85) (1/2 inch shorter for National chip board)
5V & 12V: 1.6(40.65) X 3.67(93.25)

**MatrixPC** · 08-01-2006, 05:55 PM

Originally Posted by tj!2k4

cool, gonna keep an eye on this. do you plan on "mass" producing these? if so, I'd be interested in the one that does both 12&5v.

Man, you should read the bold face words on the 2nd post.

**tj!2k4** · 08-01-2006, 06:08 PM

Originally Posted by MatrixPC

Man, you should read the bold face words on the 2nd post.

Thanks for clearing that up. That post just said "Reserved" when I asked my question/saw it earlier.

**MatrixPC** · 08-02-2006, 01:29 AM

These image are the 5V & 12V POL base on Maxim chips.
Side view

Back view

Top view with geto heatsink

**raxy** · 08-07-2006, 02:34 PM

why did you connect your yellow 12V wire to the acc entry instead of using the "regulated" output in th emiddle of the PCB ?

**MatrixPC** · 08-07-2006, 03:35 PM

Originally Posted by raxy

why did you connect your yellow 12V wire to the acc entry instead of using the "regulated" output in th emiddle of the PCB ?

The ACC is connect from a regulated 12V PSU (DSATX). There is lots of juice left on 12V rail, so may as well using it.

I didn't use the 12V in the middle cuz I just want that 12V portion to power the screens.

**raxy** · 08-09-2006, 05:59 PM

oki,
so if I connect your board directly to car battery (as most of people do not already owne a DSATX) , will I have regulated +5V *AND* +12V from it ?
What is the behaviour during cold engine cranks ? (output voltage versus input voltage)