ugliest power supply

I wonder what the price is as it leaves the factory.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

Probably around CNY70 or ~$10.

--sp

--
Best regards,  
Spehro Pefhany 
Amazon link for AoE 3rd Edition:            http://tinyurl.com/ntrpwu8

Where is the current limit adjust? I will not have a power supply in my lab that does not have a current limit adjust.

Just from casual inspection of the "naked" photos in the reviews, it doesn't look at all terrible on the inside.

It apparently has a current limit and beeper, just not adjustable.

The pass transistor is not very well heat sinked.

--sp

--
Best regards,  
Spehro Pefhany

Yeah...it's the name of the outfit I'm after.

I wouldn't be surprised if reputable independent vendors eventually surface in SEAsia, even if they're using wafer fabs imported from ex-Yugoslavia as scrap-by-weight.

RL

I've often had the same thought about other Chinese products. Example: Most smokers here use Chinese gas cigarette lighters, many of which have an LED torch powered by three button cells. Smuggled to India through Myanmar (Burma) and no doubt passing through several stages of profit-making hands, they retail here for Rs.5 (~7 US cents) and sometimes 3 for Rs.10.

I also wonder how they manage their shipping costs, even with government subsidy. I've seen zener diodes listed in *single* quantities at AliExpress, the Chinese eBay, for $0.018 with free shipping to India! And it's been my experience that they are very reliable even for such truly minor purchases.

Doesn't matter, it's going to have a fuckoff great cap on the terminals. Short it out ==> BANG! Nice fat spark.

The control loop probably responds equally slowly, too, so when it comes out of short, it overshoots to twice the setpoint.

Tim

--
Seven Transistor Labs, LLC 
Electrical Engineering Consultation and Contract Design 
Website: http://seventransistorlabs.com

Similar, but inferior, models from other companies without the RF feature and with the more common 240VAC-only input sell for CNY 70 retail including free shipping (mainland only), so I might be a bit high on that.

--sp

--
Best regards,  
Spehro Pefhany

Factory? Don't you mean garage?

It does matter. And I know how to use lab supplies appropriately. Please do not assume I am so far below your intelligence that I need for you to hold my hand. The professionals here do not need it either. If you have that problem, just ask for help.

On *every* power supply? You can't possibly know that.

Cheers

Oh, all right.

may the Morning Sun shine upon you. There are others out there.

I *highly* doubt they have anything whatsoever to do with wafer fabs. Probably just slapping dice bought from somewhere else into TO-3 cases. If you buy any from the factory be sure to arrange inspections.

--sp

--
Best regards,  
Spehro Pefhany

Excuse me? Where was my message patronizing or incorrect?

Proper use goes a long way, and I could've chosen to speak about that instead; but I suppose you would've been mad about that, anyway.

Nevermind that there are hundreds of amateur hackers on this newsgroup, who appreciate the caution from experienced users.

"Probably" == "every"? What?

I've sampled a couple of those cheap Chinastan power supplies. None are worth the scrap metal they're made from. I have not sampled this particular one.

If one of those amateur hackers were interested in a fix-it project, they're a fine starting point, and a good way to explore everything from proper control loop compensation, to proper heatsinking, to proper mechanical design -- they variously exhibit severe problems in one or more of these areas.

Tim

--
Seven Transistor Labs, LLC 
Electrical Engineering Consultation and Contract Design 
Website: http://seventransistorlabs.com

?

Maybe a CS?

Even if it were a repeatable vanity stamping, used by Flexzion for their component markings, it would be a step in the right direction.

RL

The PS-1501S seems to be offered with a number of brand names on the front panel - Best and Yihua are common - or just blank, for as low as US$15. Most illustrate the use of STMicro 2n3055 pass transistors on the rear of the case. The unbranded Flexzion part is odd in that the pass transistor is

2n3773 in the illustration, from an unrecognized semi fab. Some add a USB charging port to the front panel.

These have been marketed since at least 2014.

Best offers versions -D or -A with all digital or all analog metering. The dual digital metered version has a dramatically different package cosmetic appearance. Dual analog pricing is ~US$12.

RL

The same part number is clearly used by a number of different factories. Th is is rather common in China.

They are **marked** ST anyway. If you take the cover off there might be a surprisingly small die from some unknown fab stuck in there.

You really have to know who you are dealing with first, and sometimes also keep a close eye on them.

It's the brand of ChenYang (morning sun), like I said. They may be set up t here in Yixing because Delta was making power supplies there. All they seem to assemble are crappy TO-3 transistors like the 2N3055. There's at least two other local makers of the 2N3773.

One of the places where you can't skimp on wafer size is when using planar epitaxy as linear pass regulators. I expect anything undersized would have quickly demonstrated an abnormal failure rate, particularly in small hobby-type practice. I see no evidence reported, of such behavior in the field. 2N3773 should be overkill, though cost implications might be insignificant in the present market. Chinese OEMs have no more time for flakey suppliers than anyone else.

STMicro had plenty of surplus epitaxial power capacity over the years, from the amalgamation of Thomson/ /Sescosem/ SGS/ ATES in >4 separate 'national' fabs, that could easily have found it's way off-shore. They were also one of the last West-block fabricators of hometaxial mesa devices (per the original 3055 and 3773). I expect that a great deal of STMicro's commodity bipolar transistor capacity could easily be in Malaysia.

The 'ugly' paint colors were once used by Emerson, on similar product.

I see no company with Cheng Yang in it's name that employs the mark.

Jiangsu Chenyang Electron logo, in particular, is a circular 'CJ' with

3 ones '111' inside it: under some circumstances it might be mistaken for circle'M' (Marqhardt). It has been in business since '88 and seems to produce a predictable tooled and assembled product.

The sooner reliable 'local' chinese brands become recognized, the better. They may then appreciate the value of brand name protection....

RL

No, not that one- different Chinese characters with a slightly different meaning. "Morning Sun" =

+

This one:

They claim to have 200-500 employees, which may or may not have any validity. That's a shared website.

Another cautionary tale with "ST" 2N3055s

(turn the sound off and jump to 1:30 for the image)

--sp

--
Best regards,  
Spehro Pefhany

That's the logo, but I couldn't extract a vendor company name using simple web character translators, or even spot those for wiktionary's Chenyang symbols on the semiconductor pages.

I expect that when lower-priced parts can be regularly delivered from a Chinese mainland company, we'll see them offered (at NA pricing) on the Digikey or Mouser websites. I see Farnell offers 'Multicomp' branded parts, which may be the first chink in the wall.

Well, hobbyists shouldn't expect a cantilever bond, bumpy mesa wafers or sealant (illustrated in the 'valid' 2n3055) in the epitaxial Al stitch-bonded 2n3055s currently marketed, but the epitaxial wafer will measure roughly 5mm on a side to get the Rthjc of ~1.5C/W for the commodity part and the case marking will be resistant to wiping with IPA.

RL