USB Syncroized 5V@8A power supply POL. Now Taking Orders!!!

**Beehphy** · 10-25-2007, 11:47 PM

Originally Posted by greatwhite

Umm.......

Not to sound negative or anthing, but why would someone pay 85 bucks for a 5v supply when you could buy an 80w m2-atx for the same price?

Just wondering..........

Because you can't just have a m2-atx flopping around your trunk, hooked up and powering stuff.

there's no chassis to provide protection.
there's no good way to mount the m2 in your trunk.
you need special connectors to connect to it.
it doesn't follow the computer on/off (in a simple manner)

My product has a tough case that allows for easy mounting. simple, yet robust connectors and it has a simple and easy way to power on and off with the computer.

BTW the reason it cost $80 is cause I'm just a guy who likes to make stuff. I'm not a high volume manufacturer, so I cant buy the components as cheaply. if i could afford to buy all the stuff to make 1000 of them it would probably be lots less. the price you'll pay for one of these amounts to parts and paying me minimum wage to assemble it. I'm not even trying to recover the time or money I've invested in designing and testing.

It's not the answer for everyone.

If you need a powerful, reliable, tough 5V supply for your carputer, here it is.

**greatwhite** · 10-26-2007, 08:48 AM

OK.

I'm not trying to say your unit isn't worth it's price or application. I was just wondering what it's advantages over a dc-dc power supply were.

Good luck with your sales.

**sivart321** · 10-30-2007, 11:17 PM

Sounds interesting... im curious what the protocol currently is for when the computer powers the USB bus. Does it do it as soon as the computer begins starting up? and turn off after the computer turns off?

**turbocad6** · 10-31-2007, 12:00 AM

from what I've seen, it comes up right away, & drops off at the very end...

**2k1Toaster** · 10-31-2007, 12:12 AM

Originally Posted by Beehphy

The USB port on my device is the trigger (enable) for the power supply. the Tx and Rx lines are left floating since there is no comm with the computer. the 5V is a very low current draw (0.1mA) to enable the power supply. the computer doesn't even know it has been pluged in.

Originally Posted by Beehphy

it doesn't follow the computer on/off (in a simple manner)

I dont understand then. As soon as the motherboard gets power, USB gets power. Right before the computer shuts off, the USB shuts off. This follows the computer exactly. What is the benefit for switching off of the 5v USB when you could just use the 12v/5v already in use?

**Beehphy** · 10-31-2007, 03:24 PM

Originally Posted by 2k1Toaster

What is the benefit for switching off of the 5v USB when you could just use the 12v/5v already in use?

The 5V from the computer's pwoer supply could be used. The m2 can supply 8A @ 5V but... there are many other systems in the computer using the 5V source.

bennifits to pulling from the computers psu:
simple. easy. sync'd by default.

drawbacks to pulling from the computers psu:
Style: there's going to be an odd wire sticking out of your computer case, not your friend when goin for a clean install.
System redundancy: in the event of an overload on the 5V rail the psu goes into protect mode and entire computer powers off, possibly causing hardware/software/driver damage. this could easly be caused by the 5v rubbing against something sharp thats grounded.
Noise, a computer psu under high load is electrically noisy, not good for your sound card. and the m1 and m2 are especially noisy.

Using my 5v supply you can avoid all the drawbacks mentioned above and have the benifits too.

BTW: I am twaeking the 5A model to try and achieve 10 like I origionally proposed. I am also designing a budget model. With focus on price cutting. there are several features missing but it will still be highly functional. I think I will still offer the full featured model at the same price.

The missing features are:
No more switched 12V (unregulated 12v output sync'd with PSU)
No more seperate 12V remote enable signal input (could be done by hacking up a usb cable, the enable input at the USB connector is safe for +50V enable signal input)
No red alarm light. (green power good light will go away if protect/failed)
standby current will be higher (wont know value until testing)

Feature still intact:
ATC Fused input
overcurrent/overtemp protection
high efficiency
highly stable/steady output.
power output indicator
USB-B plug for computer sync
screw type terminal block, 4pos (12V in, GND, 2x 5Vout )
~5" x 3.5" x 1.25" Extruded aluminum chassis, painted black
Mounting tabs
Electricaly floating chassis
8-20V input range

Still simple, eligant and powerfull.

let me know what you guys think.

**Petter** · 11-07-2007, 03:58 PM

Hello Beehphy.

What's the status on your project?
Do you have anything working yet?

I think that I have been trying to accomplish the same as you are working on, only using out of the box parts. If I have understood correctly, it would be possible to solve this with a carnetix power, a 12V relay and some soldering. However there would be some obvious differences; yours in a nice box, output...

Just to be sure that I have understood how to apply your PSU, I have made a simple drawing. Could you confirm if I'm on the track.

Regards
Petter

**HiJackZX1** · 11-07-2007, 05:08 PM

Originally Posted by Beehphy

drawbacks to pulling from the computers psu:
1) Style: there's going to be an odd wire sticking out of your computer case, not your friend when goin for a clean install.
2) System redundancy: in the event of an overload on the 5V rail the psu goes into protect mode and entire computer powers off, possibly causing hardware/software/driver damage. this could easly be caused by the 5v rubbing against something sharp thats grounded.
3) Noise, a computer psu under high load is electrically noisy, not good for your sound card. and the m1 and m2 are especially noisy.

1) I have my PC on my passenger back seat. My car has complicated electronics for the seat so there is no room. I used the 12V rail to power my GPS, cooling fans, and XM adapter. I did not like the power cables with the USB so I simply added a Split Loom which covers all of them... making it nice and clean.

2) Like number 1, use split loom and all will be protected....

3) I agree with you, the M2 is very noisey. So I bought ground loop isolators from InstallEdge.com and the noise is gone with a 3 db gain and no lose of quality...all other isolators seem to muffle the sound.

Not trying to be smart at all, but i am not sold on paying 90, or even 85 dollars. I hope you do come up with a nice price budget model. I have 3 hubs and all are suffering from not having enough power......

**Beehphy** · 11-08-2007, 12:14 PM

Originally Posted by Petter

What's the status on your project?

in redesigning the simple/base model i discovered that I seem to have made a simple mathmatical error on the 10A model and will be refitting the circuit board with the correct parts soon. then retesting to see if the fix works.

Originally Posted by Petter

Do you have anything working yet?

I have the 5A with switched unregulated 12V version working for sure. those are the numbers for it a few post above. the 5A without 12V output is still under development.

Originally Posted by Petter

Just to be sure that I have understood how to apply your PSU, I have made a simple drawing. Could you confirm if I'm on the track.

you have it right, except for the regulated 12V. the 12V output from my PSU is unregulated. If your LCD screen can handle raw 12V (12-14.6V) from your cars electrical system this will pose no problem.