Products > Test Equipment
HSPY Power Supply
(1/8) > >>
TurboTom:
Recently I've been searching for an inexpensive, moderately high voltage laboratory power supply. Since once in a while I work with vacuum tubes or discharge lamps or similar toys, and the ripple / noise of the average electrophoresis power supplies is really sub-par and moreover, these devices are quite picky of the load they are connected to (the latter can usually be worked around...), I needed a more "lab-style" instrument.

After searching the web for quite a while, I stumbled over the small PSUs made by "Bejing Hanshengpuyuan Technology Co. LTD". These devices look really simplistic as if they originate from the 1980s but the specs and description impressed me. They are supposed to be switchers with a linear second stage regulator. So I decided to have a go with the "HSPY-400-01" which is a 400V 1Amp unit, available for the equivalent of 200USD, give or take a little.

Two weeks later I received the parcel, unfortunately had to pay impot VAT & customs fees but what the heck, it still was cheaper than anything locally available in this class, provided it worked as advertised.

Initially I was really amazed by the size of this unit, it's almost unbelievable that it should be possible to squeeze 400W out of a box that small in decent quality. It was also a surprise to me that the whole enclosure is made up as a welded steel sheetmetal construction, there's not the usual plastic front/base with a folded sheet metal cover. This may contribute a little to it's dated appearance but it should provide pretty good RFI shielding and be quite robust mechanically.

Of course, I took it apart before I turned it on! Man, this thing is full of electronics and quite a complex beast. Maintenance-wise it is not far from a nightmare I guess but so far there didn't arise the need for this. The device contains a total of three switchers (one for the control circuitry, one for the fan -- yes, the fan got an individual SMPS which also provides power to the isolated RS232 control port --, and of course the main power switcher). The device appears to be equipped with a PFC circuit, and as mentioned in the description, there is a second stage linear regulator -- impressive! Moreover, there's EMI reduction stuff everywhere, maybe a total of six common-mode chokes distributed over the PCBs (and one hanging in "free air"). I found the insulation clearance around the fan SMPS PCB to the metal enclosure to be almost non-existant so I applied some thick kapton tape in this area -- should be okay now.

After reassembly, the functional test reveals that the power supply performs really well. The voltage is spot-on and the current calibration looks also quite good as well. Set and read voltage / current are displayed all continuously on a single two-line 16 chracter LCD. Power isn't displayed unformtunately. The command set of the RS232 interface isn't documented (at lest not in any format that would be explanatory to me, the A4 sheet of paper that I would interpret as a manual in chinese writing refers to "Modbus" at one place). I loaded the PSU with 0.9amps at 250V setting to check the ripple. I found it to be round about 70mVss at the switching frequency of 110kHz (frequency is load-dependant). There is still some superimposed common mode noise in the ballpark of 0.4Vpp that may be related to anxious me running the thing off an isolation tranformer and not having the case grounded. If I touched the PSU's enclosure and with the other hand the oscilloscope's ground, this noise was reduced considerably. I did a high-pot test of 1kV between AC input and earth and didn't observe any leakage (> 2GOhm). The PSU comes supplied with a set of alligator clip leads as well as an RS232 cable and an IEC power cord with an unidentifyable plug at the other end. An adapter is incuded that interfaces this plug to a (continental) european wall outlet, but this lacks PE so I just threw the mains cord and the adapter in the bin and replaced them with a proper cord.

So far I'ld say the power supply is worth the money though it may be wise to ckeck the isolation clearances as I did. I'll report any additional findings that may come up during use. Attached some photos of the teardown.

Cheers,
Thomas


Edit: Typos...
Hydron:
Thanks for the review - I am interested in such a supply too. It looks like they are also available on the Amazon UK marketplace - ships from China and is ~10% more expensive, but as it is sold on the UK site in GBP I think this means that the seller deals with VAT/customs fees? (Would need to check this to be sure!).

The "unidentifiable plug" is probably the standard Chinese 10A plug with pins in a Y type shape. This is similar to the NZ/Australian plugs (can normally be interchanged), but replacing it with a non-chinese IEC lead is probably wise!
genghisnico13:
Nice find, the only downside I can think of is the fan, looks like one of thoose high RPM ones that produce a high pitch whine, but other than that, looks good.
TurboTom:
The fan is actually temperature controlled by an NTC bolted to the heat sink of the linear regulator's pass transistor. It's barely audible at idle or low power operation.

Yes the mains connector is exactly as you described, Hydron. Maybe I should keep the cable in case I'll ever get in the "parts of the woods" where this plug fits...  ;).

Actually it appears that I was at fault with the PFC I mentioned in my introductory post. The inductor that I mistakenly identified as the PFC boost coil actually is part of the tank circuit of the (as it seems) half-bridge LLC topology converter. It's quite funny that the manufacturer utilized this topology despite the large output voltage range of the PSU.

Cheers,
Thomas

Edit: Added new information
jwinter:
Another thanks for the review. This HSPY company sells an amazing range of power supplies with different ratings - just search aliexpress.com for "HSPY".  We bought about a dozen lower voltage supplies for our university's second year laboratory - which were really great for a year or two until some official noticed that they did not have a C-tick or CE type approval sticker on them!  This means that they cannot be used in the uni and so we had to "dispose" of them all (which was very beneficial to the electronics hobbyists among the staff!).

It seems you have purchased one quite recently - so I wonder if you can check whether they have started putting CE marking on them yet.  I would guess that they would need this in order to sell them on Amazon UK as Hydron mentioned.  I wonder whether you have any advice to offer with regard to safety and CE type approvals?

One thing we did notice with the lower voltage units that we used was that they had a pretty large capacitor across the output - which means that if you set them to current limit at say 20mA, you can get a much higher current than what you set when the capacitance discharges.  For instance you might want to push 20ma through an LED - so provided you set it up for that and turn it on with the LED already connected all is fine.  But supposing you jiggle the connection to the LED so that it momentarily becomes disconnected and the voltage rises rapidly (as a current source is supposed to), then when the connection is made again the LED flashes brightly and dies!
Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod