Compact OVEN BP60A-S power supply for automation cabinets

Another power supply from Owen: 24 V again, with an extended temperature range again. Unlike the previous one, though, it has lower power and is much smaller.
So, let's continue our discussion of panel-mount equipment from domestic manufacturers.

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As always, the link in the title goes to the Ukrainian website; for readers in Russia, here's a link to the Russian site. By the way, I happened to notice that this power supply is a little cheaper in Russia, at around $60.

So, last time I reviewed a 24 V, 120 W power supply with an operating temperature range of -40 to +70 degrees. This time, the power supply has the same voltage and temperature range, but is rated for an output power of 60 W. It's also a fairly new model, which has indirectly affected its size, making it noticeably more interesting in my opinion.

The packaging is basic, but personally, all I care about is that nothing rattles around inside.


The contents are identical to the previous model: the power supply itself, a manual in two languages, and a warranty card.


The manual is quite detailed, so no complaints there. If that's not enough, you can download an electronic copy.
The warranty card lists the date of manufacture and the warranty period, which is 2 years. Personally, I think that's too short, especially given the price and the product's intended use in the professional segment.


The manuals in Russian and Ukrainian, as well as the certificate of conformity, can be downloaded here. As usual, I'll include screenshots below.
I'll start with the technical specifications, but first, a quick note. This power supply series includes several models with:
1. 30 W or 60 W power
2. 12 V or 24 V output.
3. A standard or extended temperature range (C suffix).
That makes 8 models. This review covers the BP60A-C: 24 V, 60 W, with an extended temperature range.


It looks noticeably better on the outside: compact, understated, and neat.


1. The front panel has the terminal blocks, power indicator, and output voltage adjustment potentiometer.
2. The familiar DIN-rail clip is on the bottom.
3. The left side has information about the power supply, along with a bunch of extra ventilation holes. How well they'll work in a packed panel is still a mystery to me, though.
4. The right side shows the permitted wire cross-sections and stripping length.


1. The terminal blocks are the same "elevator" type as on the previous power supply, but these are removable. That may reduce reliability, but it makes the unit noticeably easier to use.
2. The width is equal to two standard modules.
3, 4. The unit is considerably taller than common modular equipment, so it simply won't fit in a standard "residential" panel. Here's a photo, for example, with a circuit breaker and a Mean Well power supply of the same power rating.


The power supply dimensions are shown here, along with a warning about connection details.


The insides—what would a review be without them? :)
The power supply is extremely easy to take apart. You don't even need a screwdriver: just unclip the side cover, gently pry off the front panel, and remove the board.


Inside, the board looks very neat—I'd even say beautiful. You can already tell it's a single-switch flyback converter. The first thing that seems a little unusual is the microscopic heatsinks on the power components.


All the other components are on the underside. The board is coated with varnish to improve reliability.


The primary side uses the same PWM controller as the previous power supply, the UCC28C44, but this one is a flyback design without active PFC.


The output stage also uses the same Z103WA chip, but with one small addition: there's another chip here, marked IR11672A. This chip controls the synchronous rectifier.
You can also see the current-sense shunt here, which means the power supply can operate in CC/CV mode. This also allows several power supplies to be connected in parallel, either for redundancy or to increase power.

Here I'd like to say a few words about the soldering. As far as the SMD components go, everything is great, but after soldering the through-hole components, I’d still like to see the board a little cleaner. I wonder if they happen to have an opening for a head of quality control? :)
No, actually, in this case it’s more a matter of aesthetics, but still.

I should also note that a protective slot under the optocoupler wouldn’t hurt.


1. The input filter is pretty good, but they squeezed in the X capacitor on the mains side, even though I think it would have made more sense to put it there.
2. The input also has a fuse, thermistor, and varistor, which is useful.
3, 4. A slightly odd Y capacitor. What’s odd is that it has no compliance markings at all.


1. At the input, there are two Nippon Chemi-Con KXG series capacitors, rated at 82 µF and 400 V, connected in parallel.
2. The primary-side high-voltage transistor.
3. Since this uses a synchronous rectifier, there’s a transistor in place of the diode. It’s also a little unusual to see a Toshiba transistor; I haven’t seen one in a long time — datasheet
4. At the output, there are four Nichicon capacitors rated at 470 µF and 35 V each. They’re from the PW series, with a decent amount of headroom in this case.
There’s also an output inductor to reduce ripple, wound with fairly thick wire.


The power supply was initially set to 24 V, and quite accurately at that. The adjustment range is 21.80–26.24 V. The adjustment is very smooth; I wrote about this and why it’s useful last time, too.
I also noticed that power consumption without a load depends noticeably on the output voltage.


As before, I used the EBC-A10H with a four-wire connection for the tests.


Load test at an input voltage of 230 V. The protection kicked in at around 2.85 A, and voltage regulation was excellent.


The same test at an input voltage of 100 V; the behavior was exactly the same.


The manufacturer provides a graph showing efficiency versus temperature and supply voltage.


I wouldn’t call the efficiency particularly high; it could be better, but it’s quite decent and a little above the stated 85%.


Ripple was also checked at two input voltages: 230 and 100 V.
First, 230 V:
1. No load
2. 20 W
3. 40 W
4. 60 W
5. 20 W at low frequency
6. 60 W at low frequency.

The stated ripple was up to 60 mV nominally and 120 mV maximum. In my tests, it was significantly lower, reaching only about 20 mV even under the worst conditions.


At an input voltage of 100 V, ripple increased, but still stayed below 30 mV—half the stated value. The difference was more noticeable in the low-frequency ripple at maximum power.


Like the previous power supply, this one can also operate in constant-current mode. That is, when overloaded, it starts reducing the output voltage and switches to current regulation, which allows power supplies to be connected in parallel.


To test this feature, I connected a load with voltage regulation (CV mode) to the power supply output.
1, 2. I gradually lowered the voltage until it switched to current regulation. The current stabilized at 2.8 A, down to 11.8 V.
3, 4. As the voltage is reduced further, the current rises to 3.3-3.4 A, and below 7.5-8 V the power supply goes into protection.


The current results are within the specified values, but only down to a 50% voltage drop. Still, in my view, it seems unlikely that the power supply would be used in CC mode at a voltage below 12 V.


The waveform in constant-current mode: at very low voltage settings, the ripple is quite noticeable, but across the 12-24 V range it looks very good overall.
On the left is the setup I used for the measurements above, with a 1+0.1 µF parallel filter; on the right, the probe is connected directly. Even so, under this heavy operating condition, the ripple remained within spec at around 25 mV.


The “soldering iron test,” or a test with a sudden load change from almost zero to 2-2.5 A, went reasonably well, but you can see that the power supply is working fairly hard. I think this is because, in practice, these are current surges across the power supply’s full power range.


The manufacturer provides two graphs showing output power versus temperature: one for the standard version and the other for the version with an extended temperature range. For the standard version, the load power has to be reduced after 50°C, all the way to zero at 55°C. For the “C” version, this derating range starts at 70-75°C.


I had to check the thermal performance in this setup: the board was out of its enclosure and covered with a lid to simulate installation in a control cabinet. Of course, it would have been better to install it in a cabinet and take temperature readings inside the closed enclosure, but unfortunately that wasn’t possible.


The first test was run at an input voltage of 230 V, in three 20-minute stages with load powers of 20, 40, and 60 W. The second was run at an input voltage of 100 V, in four stages: 20, 40, 60, and 62 W.


Temperatures at key points were measured during the tests. The most significant result was the transformer temperature, which reached 92°C.
Also, if you look closely at the output rectifier temperature (D.out), you’ll notice that at 60 W it gets about as hot as—or even cooler than—it does at 40 W. That surprised me, so I ran a third test under the same conditions as the first to double-check, and got similar results.



Here’s what the thermal images looked like: the top row shows stages 1, 2, and 3 of the first test; the bottom row shows stages 1, 2, and 4 of the second. Here too, you can see that the output rectifier doesn’t get hotter as the power increases.

In any case, I was pleasantly surprised by the semiconductor temperatures, though I’d consider optimizing the transformer. Ideally, a power supply shouldn’t have components with markedly different operating temperatures, especially when it comes to power semiconductors and the transformer.


As a final check, I ran a one-hour test at maximum power with the power supply in its enclosure, standing vertically on the table.


And the last test: checking how accurately the output voltage is maintained as the unit heats up and the load changes.
1. No load, at the start of the tests.
2. Full load, after an hour of warm-up.
3. No load, after an hour of warm-up.

I’d say that’s perfect.


Conclusions.
In terms of both electrical performance and thermal behavior, the results look very good to me—excellent, even. Ripple is low, voltage regulation is excellent, CC mode works, and temperatures are moderate.

The only thing that could spoil the picture is the price: $70 is still a lot. But I won’t get into pricing; my job was to assess the quality of the power supply itself. And I have no complaints about its quality—or almost none, since the soldering could be a little neater.

That’s all for now. As always, I’ll be glad to hear your questions and comments.