S-10-5 power supply schematic etc. 5V 2A

[redwire]

I got a 5V 2A power supply for some hobby projects from Aliexpress store YXD Wish for about $4. S-10-5 and the build quality good, solder blob under transformer and a solder balls on the PCB top so I cleaned that up.

Powered it up, get 5.0V but when connecting a load resistor it cratered. At 10R load which should be 0.5A, it dropped to 3.8V out and it went into hiccup mode below 5 ohms. About 1.5W output is all I can get.
I drew out the schematic and poked around with a scope. It's running slow at 31kHz and primary current pulses are measly 30mA. So I think the IC is fake and not working, it has no markings.
It appears to be a TX203H alternates are CR6203, RM6203, SDC603, SW2604, SL2128B. Commonly used in wall warts.
(The bottom rung version of this same S-10-5 using phenolic PCB, uses IC DK1203 Dongke Semi and no current-sense resistor, and cheapened other stuff.)

I asked for a refund and so far the vendor is quiet... I had another one ordered from a different Ali store but the floods took out rail and highways to the coast so it will be a while to get here and compare.

Don't forget website comparing pinouts of SMPS IC's. Good tool to reverse-engineer the IC used when there are no markings or it popped.

[stj]

i would only buy MeanWell stuff at this point.
they arent piss-cheap but they arent crap either
https://meanwellonline.aliexpress.com/store/5429250

[sam_sam_sam]

Has anyone used this type of switching power supply

Brand : Mean Well
Model : PSC-160A-C
Output CH1 : 13.8V / 7.6A
Output CH2 : 13.8V / 4A (Battery charge)
Rated Power : 160W

[stj]

you probably need to ask on a cb radio forum with that output

[redwire]

The problem with these smaller power supply modules, they're always missing parts to be cheap.
I look for: a fuse, common-mode choke/X-cap for EMC, NTC and decent sized primary cap. It's too much to ask. A name-brand AC wall-wart has all of that. But who wants to glue that down in your enclosure.
I have another board, high quality - but the transformer runs pretty hot even at 1A load.

In the 10W league, it's cheap chinese open-frame, or "high end" $20 potted modules like CUI PSK-S12B module. CUI VOF-10B rated 3-year life and has Teapo caps. UGH.
Meanwell I'd looked at it was all big, 25W-50W is the smallest ,then the potted modules IRM-10-5V but who knows what's inside.
Popular is the Hi-Link HLK-PM01 modules but no fuse, no input EMC filter.

I'll keep looking, it seems easier to mod a cheap open-frame one.

[lti]

Delta also has some decent power supplies (although I saw a big fan-cooled one that appeared to adjust fan speed based on load instead of temperature), but they only go down to 15W.

[CapLeaker]

I used a shitload of these Meanwell power supplies mainly wall warts. So far I had good luck with them, zero problems. I also used bigger Delta power supplies and they were also good.

Redwire: that link doesn’t work for me.

[eccerr0r]

Originally Posted by redwire

Don't forget website comparing pinouts of SMPS IC's. Good tool to reverse-engineer the IC used when there are no markings or it popped.

Should there be punycode here instead of *'s?

[sam_sam_sam]

Originally Posted by CapLeaker

I used a shitload of these Meanwell power supplies mainly wall warts. So far I had good luck with them, zero problems. I also used bigger Delta power supplies and they were also good.

Redwire: that link doesn’t work for me.

It does not work for me either

[lotas]

"****************/ic_power/"

[redwire]

The URL for the Russian website comparing pinouts of SMPS IC's gets turned into asterisks here like this: ht tps://****************/ic_power/
Trying to post them, just delete the spaces to get the URL:
Home page: h ttps:/ / remont-aud . n e t /load
AC-DC SMPS IC identification: h ttps:/ / remont-aud . n e t /ic_power/
DC-DC SMPS IC identification: h ttps:/ / remont-aud . n e t /dc_dc/
Some service manuals there too, use google translate.

Aliexpress store YXD Wish said nothing about their dud S-10-5 power supply, sent them pics too. "Aliexpress guaranteed return shipping" means... I have to pack it up and pay probably $15 to send it back to china. UGH

Good news, the second power supply came in and I will post pics and schematic. At least it works.

[CapLeaker]

Originally Posted by redwire

The URL for the Russian website comparing pinouts of SMPS IC's gets turned into asterisks here like this: ht tps://****************/ic_power/
Trying to post them, just delete the spaces to get the URL:
Home page: h ttps:/ / remont-aud . n e t /load
AC-DC SMPS IC identification: h ttps:/ / remont-aud . n e t /ic_power/
DC-DC SMPS IC identification: h ttps:/ / remont-aud . n e t /dc_dc/
Some service manuals there too, use google translate.

Aliexpress store YXD Wish said nothing about their dud S-10-5 power supply, sent them pics too. "Aliexpress guaranteed return shipping" means... I have to pack it up and pay probably $15 to send it back to china. UGH

Good news, the second power supply came in and I will post pics and schematic. At least it works.

Thanks redwire!