[Dennis]

While this can be done to make a cheap DC-DC converter it is not something I would use because the components are commercial grade which are only guaranteed to work over temperature ranges of 0C - 70C. Zero degrees centigrade is only 32F which it gets much colder than that up north. Reliability starts to become an issue......I suppose you could change out of the components with automotive or military grade components which can work at much lower and higher temperatures.

[lazzer408]

A DC-DC convertor is no different, component wise, than this. This actually has much higher regulation and is power factor correcting. Considering it's designed for the computer industry and has UL, CUL, TUV, FCC, BSMI and CE certifications, I'll assume it's fairly reliable. I haven't seen that in a commercial DC-DC convertor. The only thing that may effect it over time is vibration and humidity but the open chassis commercial units are just as susceptible to the elements. The PFC PWM IC used is a CM6800G rated for -40 to 125c (that's 257deg F). The capacitors would have exploded by then. Which are all 105c caps by the way.
For what a DC-DC costs I can buy 3 to 6 of these.

[Dennis]

A DC-DC convertor is no different, component wise, than this.

Yes I know they use the same components except some extra for the AC-DC conversion for the computer switching power supply.....You seem very confident that a computer power supply will be reliable with all those agency seals on it. If you have such confidence then are you willing to make some test setup for a computer switching power supply in an environmental stress screening chamber? Set the temp to -20C (-4F).

[lazzer408]

Sure...if I could afford it. I can throw it in the freezer for ya.

[Twilly]

Lazzer... I reciever my 450 today... It has 2 - 30 amp outputs... Did you connect both outputs to your car, or only one?

The info says it is good from 90 to 264V AC... How does that convert to DC?

Thanks for the info on this, And can you give us a hint on your next BIG project...

Twilly

[Dennis]

The info says it is good from 90 to 264V AC... How does that convert to DC?

Usually the DC output for full wave rectification will be .636*Vpeak - 1.4 volts of two diode drops. With a capacitor the output voltage will approximately equal the Vpeak of the sine wave assuming no heavy loading.

[lazzer408]

Originally Posted by Twilly

Lazzer... I reciever my 450 today... It has 2 - 30 amp outputs... Did you connect both outputs to your car, or only one?

The info says it is good from 90 to 264V AC... How does that convert to DC?

Thanks for the info on this, And can you give us a hint on your next BIG project...

Twilly

Can you get me a few close up shots of the circuit board. Top and bottom. On my 250w I paralleled the outputs. Internally there was only one 12 rail that was fed thru 2 shunts into 2 outputs. The only reason I can track down for the shunts is for the status LEDs. Send me some pics.

[Twilly]

Here are the pics... I see what you mean, all the leads come from one trace...

What about your next project???

[lazzer408]

On the bottom of pic 005sm is the bridge rectifier I take it. Hook your DC to the + and - legs of it.

What was it I needed pics for? I forgot. To many projects atm.

You can parallel the outputs if you like. Tie all the yellows together for your positive and all the blacks for your negitive. Or just run a nice piece of 8ga to it. Look near the output traces and you should find a small opto-isolator. There should be a pile of resistors around it. The 12v output of the psu lights up the tx-side LED inside the opto. That's the side you need to tweek. It tells the recieving end what the voltage is. Those resistors make up a voltage divider on both the cathode and anode of the opto. Get me a close up (use camera's macro) of that area.

EDIT - I see them in pic 004sm. Looks like there's 2 in the middle and one on the left side. I -think- it's the right of the two in the middle. It's hard to see the traces. Get a better camera!

[lazzer408]

Originally Posted by Twilly

What about your next project???

If ah tell u I haf to keil u