Hard Drive Power Supplies

[budm]

Re: Hard Drive Power Supplies

jameco.com:
http://www.jameco.com/webapp/wcs/sto...0001_323505_-1

http://www.jameco.com/webapp/wcs/sto...0001_323425_-1

http://www.jameco.com/webapp/wcs/sto...0001_323362_-1

[mariushm]

Re: Hard Drive Power Supplies

Can't really compare a TDK power supply with a Meanwell. Yeah, meanwell will work, but with a lousy efficiency and potentially high ripple on outputs.

If you go that route, you could just as well pick the 14$ special on newegg, a shitty logisys : http://www.newegg.com/Product/Produc...16&ignorebbr=1

[budm]

Re: Hard Drive Power Supplies

Meanwell spec

[mockingbird]

Re: Hard Drive Power Supplies

Sorry to bump an old thread, but I came across another variant of the Yu Feng, and it is almost completely identical to it except that this one has a brown PCB and all Capxon caps (KM and KF).

The soldering of the underside of this one is a lot cleaner, and this one has "23-11056-00 REV. A" written on it.

The datecodes on the caps indicate this was made in the beginning of 2005.

[kaboom]

Re: Hard Drive Power Supplies

mine developed a primary to secondary short and zapped the living shit out of me today. found carbon traces on the underside of the board.

Interesting. This confirms there is no secondary-to-EGC bonding. Which means when they fault while connected to the computer, the USB cable does fault duty. If the EGC were connected to the secondary common, [i]as it is in every by-code power supply," all that would've happened is either the carbon traces burn clear, or the fuse blows. And that assumes the fuse in in the hot wire.

Who wants to guess that the induced voltages on the USB pair don't kill the host controller?


I actually borrowed one of those SATA/IDE->USB things after I couldn't use the SD card reader on a semi-trashed shitsta system. Someone working at the same place also does networking. I told him about those power supplies, but all I got was "It's fine for backups."

I go back there this weekend and will have to print this thread and leave it. It confirms my suspicions that the "three-wire" AC cord is only for "show."

They're as bad as the fake apple chargers as far as shock hazard...

[goontron]

Re: Hard Drive Power Supplies

well, since the thread was dug up...
This is the Unit i use now to power drives externally. It came out of a well built HP tape drive.

Notice the proper isolation and air-gaps, duely optocouplers, thick secondary traces, and good filtering all around. It doesn't disconnect the primary to shut off, it just kills the primary switchers, so that heatsink on the primary switcher is always live. (i learned that the hard way) No brown gorilla snot here! Only issue i have with it is crap caps, but its not enclosed and doesnt run hot, so im not too worried..... HP drove the tape motor from 5V, can you tell?

[kaboom]

Re: Hard Drive Power Supplies

well, since the thread was dug up...
This is the Unit i use now to power drives externally. It came out of a well built HP tape drive.

Notice the proper isolation and air-gaps, duely optocouplers, thick secondary traces, and good filtering all around.

It doesn't disconnect the primary to shut off, it just kills the primary switchers, so that heatsink on the primary switcher is always live. (i learned that the hard way)

Betcha won't do that again...

No brown gorilla snot here! Only issue i have with it is crap caps, but its not enclosed and doesnt run hot, so im not too worried..... HP drove the tape motor from 5V, can you tell?

5.5A on +5, maybe...

[goontron]

Re: Hard Drive Power Supplies

Betcha won't do that again...






5.5A on +5, maybe...

ahh, better for running laptop drives!

[mockingbird]

Re: Hard Drive Power Supplies

Just a heads up, there have been HDDs spotted in the wild that require 3.3V.

So the ideal HDD adapter would have 12v, 5v, and 3.3v, and two connectors, one SATA power, one molex.

[goontron]

Re: Hard Drive Power Supplies

Just a heads up, there have been HDDs spotted in the wild that require 3.3V.

So the ideal HDD adapter would have 12v, 5v, and 3.3v, and two connectors, one SATA power, one molex.

sigh, i will rig something up.

[kaboom]

Re: Hard Drive Power Supplies

Severe RFI from one of these turds:
http://www.eham.net/articles/34513

As soon as I saw them on ebay and newegg a few years ago, it was obvious they'd be causing trouble.
The missing filter sections, on the line side, are important.

So in addition to shock hazards from carbon tracking/untrimmed leads and no EGC bonding to the secondary common, they also function as "RFI generators," disguised as power supplies...

Or, cow pies, disguised as power supplies.

FWIW, a few days ago, I crushed a Raidmax under my foot- output leads all labeled #20AWG, but probably were ~#21AWG. +3.3 had no magamp and shared the common inductor with +/- 5/12. No pi-sections on the outputs. Ceramic y caps instead of proper ones, missing line-side filter sections. AC rectifiers were two 4005s and two of something between those, and 2A05s. Bigger than a 400x, but not quite a 2A device.

And, by the way, it also needed caps. To coin a phrase, "Jee Saturn, Fuhjyi-yoo!"

That junk was gone. It'll never have the potential (!) to stress (kill?) another system... At least it was now "ultra-small form factor."

[goontron]

Re: Hard Drive Power Supplies

ok, mine developed an issue. it pulses on switch one then eventually starts. Thats a startup cap issue right?

[kaboom]

Re: Hard Drive Power Supplies

ok, mine developed an issue. it pulses on switch one then eventually starts. Thats a startup cap issue right?

10-22u, 50V, near the SMPS IC, likely a cheep submini electro. Probably right by the transformer. You can use anything from 10-47u, 50V. It's quite possible that the aux voltage is nowhere near that; a 25 or 35V cap could work, but either measure it or find out what voltage the SMPS IC clamps it at. Some have an interal shunt reg, that limits the voltage across that cap- it's fed thru a resistor after the aux rectifier/winding.

And if you're going to change the O/P caps, why not do a before-and-after scope 'n load test?

If you have a scope, that is...

I'm betting you've got well over a volt of ripple on +12, even at 1A. More if there's no pi-filter.

Don't forget to bond common to the EGC and rewire the AC input, putting the fuse in the hot, where it belongs.

[stj]

Re: Hard Drive Power Supplies

maybe.
or bad solder joints.

[CapLeaker]

Re: Hard Drive Power Supplies

either a bad starting cap or bad solder joints. Some are really hard to find. Read this thread:https://www.badcaps.net/forum/showthread.php?t=47479
I finally found it with my hot air soldering station.
Norstar: 0
CapLeaker: 1

[goontron]

Re: Hard Drive Power Supplies

10-22u, 50V, near the SMPS IC, likely a cheep submini electro. Probably right by the transformer. You can use anything from 10-47u, 50V. It's quite possible that the aux voltage is nowhere near that; a 25 or 35V cap could work, but either measure it or find out what voltage the SMPS IC clamps it at. Some have an interal shunt reg, that limits the voltage across that cap- it's fed thru a resistor after the aux rectifier/winding.

And if you're going to change the O/P caps, why not do a before-and-after scope 'n load test?

If you have a scope, that is...

I'm betting you've got well over a volt of ripple on +12, even at 1A. More if there's no pi-filter.

Don't forget to bond common to the EGC and rewire the AC input, putting the fuse in the hot, where it belongs.

remember, this isnt one of those cheap units. Its an HP tape drives internal PSU. EGC is already bonded, has fuse, pi-filter, etc. i will look for bad soldering and replace that cap.
I have tested the output caps. one was bad, and i replaced it.

[kaboom]

Re: Hard Drive Power Supplies

remember, this isnt one of those cheap units. Its an HP tape drives internal PSU. EGC is already bonded, has fuse, pi-filter, etc. i will look for bad soldering and replace that cap.
I have tested the output caps. one was bad, and i replaced it.

That's what I get for ass-u-me-ing..

[goontron]

Re: Hard Drive Power Supplies

That's what I get for ass-u-me-ing..

that light green one has a black marking on the top. i put that there because it wasn't out of tolerance, but it was high, its graphite. It looks like its just doing filtering and with a rating of 1500uF i'm going to replace it with a 2200uF anyway. Lets see how it does with new low value caps!

[goontron]

Re: Hard Drive Power Supplies

No dice. still does it.

[kaboom]

Re: Hard Drive Power Supplies

Resolder the pins on the TX primary side, and also replace the diode feeding the cap for the PWM IC.

Don't check and assume it's good- they can get fussy til they warm up.

Back in the late 90's, I fixed two of those "Packard Bell" Pixie monitors.

+12 was missing for about 20 minutes after a cold start and supply was cycling. Degauss relay was powered by that same +12, so it would click too.

I fed +12 in from a seperate supply and it came to life. First I changed the cap- no change. Then I isolated that feed and checked for shorts. No shorts.

For testing, I replaced the schottkey with two 1N4004s. They got warm (hot?), but unit now worked.

All was well after a new TO-220 schottkey; cap was still OK.