StarGT 250W AT

[370forlife]

Found this old computer free on the side of the road. This thing has all the cheapest off brand manufacturer stuff on it. Soyo motherboard with Mteq chipset, unknown manufacturer sound card, unknown manufacturer modem, S3 video card, O.K. Data ram, and it had this power supply in it. About the most gutless wonder I have ever seen in my life. The UL number leads to Real Power enterprises. Tiniest transformer I have ever seen. But what is the purpose of that second smaller transformer?



Almost no input filter except for a coil and 2 tiny y caps. Input caps are 220uf 200v Capex brand.



The primary switchers are 2 sanyo 2sc4161's, 400v, 7A, 14A pulse.



Secondary heatsink. The 5v is regulated by that 30A, 45v schottky you see there, while the 12v is handled by 2 FR30's, good for 3A each. The 12v on this is rated at 10A.

Secondary filtering is taken care of by capex and some CEC international's.



Daewoo dbl494

I don't think there is any protections what-so-ever on this thing.

[kc8adu]

Re: StarGT 250W AT

the smaller transformer is for base drive to the choppers.
and yes thats about as gutless as you can get in an at.

[japlytic]

Re: StarGT 250W AT

The smaller transformer is for current sensing too.
I have seen the "Capex" brand of electrolytic capacitor in a cheap small B&W TV and radio - any more information on this capacitor brand?

[everell]

Re: StarGT 250W AT

Its not such a bad power supply ......... it doesn't have a two transistor "fire hazzard" 5vsb circuit.

[370forlife]

Re: StarGT 250W AT

I think it might just use some salvaged parts and caps to make this a little better. One big step up will be replacing the transformer with the old 33 transformer from my yuelin. Replace those two diodes with something like a 20A, 45v schottky from a sunpro, some X and Y caps laying around, 4A, 400v bridge rectifier, maybe some 470uf primaries and replace the secondaries. Use it to bring my old biostar-quantex board back to life.

[Per Hansson]

Re: StarGT 250W AT

everell; lol, indeed
We have here found the indestructible 5VSB circuit!

[dood]

Re: StarGT 250W AT

The 12v is low because the only thing that would use it was the drives back then. Pretty much everything else ran off your 5v and 3.3

[POM_MJ]

Re: StarGT 250W AT

Its not such a bad power supply ......... it doesn't have a two transistor "fire hazzard" 5vsb circuit.

I've agree with that.

[ratdude747]

Re: StarGT 250W AT

Its not such a bad power supply ......... it doesn't have a two transistor "fire hazzard" 5vsb circuit.

and thats all you can say for it... what a POS!

the worst i've seen is this LSI at thing rated for 235w, but it has no guts, no filter, 4 diodes, tiny finless heatsinks, poor ventalation, thin wire, just plain old s***ty. it was a hell of a lot worse than your gutless wonder... sometime i'll post pics of my LSI so you all can lose your lunch.

[everell]

Re: StarGT 250W AT

I am curious as to what you were referring to "your gutless wonder". Hopefully you weren't talking about my Bestec ATX-250 12E with 5vsb circuit converted to DM311 chip and dual fans for less heat generation and improved cooling. I think my Bestec is now a classic!

As for the StarGT 250 watt AT, it does come up on the "lacking" side, especially the 5vsb circuit.

[ratdude747]

Re: StarGT 250W AT

i meant the psu in this thread... starGT 250w AT

[pfrcom]

Re: StarGT 250W AT

Its name implies it's an AT power supply, rather than ATX

I thought AT power supplies didn't need a 5VSB circuit, because they used a mechanical On/Off switch

[etnietering]

Re: StarGT 250W AT

Yeah that's right, AT only has +/- 12v and +/- 5v outputs. The power switch is hard wired to the input AC line. When an AT computer is off, there as no electricity (except transients from discharging caps) flowing anywhere.

[everell]

Re: StarGT 250W AT

That's right. AT power supplies do not have a 5vsb circuit. That's why it doesn't have a "killer" two transistor 5vsb circuit. That was the only redeeming value I saw in this power supply!

[370forlife]

Re: StarGT 250W AT

The 12v is low because the only thing that would use it was the drives back then. Pretty much everything else ran off your 5v and 3.3

Well, 6A of diodes for the 10A rated 12v rail doesn't seem right to me.

[Per Hansson]

Re: StarGT 250W AT

pfrcom; you are very correct
Sometimes our humor and or sarcasm on this site might be a bit hard to understand

[pfrcom]

Re: StarGT 250W AT

Thanks for letting me down gently Per Hansson - I didn't realise I'd stumbled into the middle of a bulldust swapping session