Mean Well HDR-60-12 power supply, the fourth of six

As you’ve probably guessed, this is a compact power supply designed for mounting on a DIN rail. Besides industrial applications, power supplies like this can also be useful for home automation systems, “smart” homes, powering video surveillance systems, and so on.
This kind of use is largely dictated by the power supply’s form factor, since it can be installed in a standard residential electrical panel.

This time, the power supply came in its original cardboard box, with a small window.


As usual, there’s nothing else in the box besides the power supply. You’re expected to download all the instructions and recommendations from the internet. To make things a little easier, I’ll include screenshots in this review, but you can also download the full documentation.
Full description in English



The manufacturer lists the following key features for this power supply:
1. Ultra-compact design — 52 mm (3 units). That’s debatable, to put it mildly, since there are power supplies just 1 unit wide.
2. Wide input voltage range
3. No-load power consumption below 0.3 W
4. Designed for operation in confined spaces
5. Adjustable output voltage
6. Short-circuit, overload, and overvoltage protection
7. Natural convection cooling
8. 3-year warranty



The front panel has just a power indicator. A little higher up, there’s a hole for adjusting the output voltage.

The input wires connect at the bottom, and the load connects at the top.


There’s a brief reminder on the side: use copper wire for the connections, and make sure the ambient temperature doesn’t exceed 45 degrees.


The HDR-60 series includes five models with different output voltages: 5, 12, 15, 24, and 48 V. Note that only the 15, 24, and 48 V models deliver the full 60 W. The 5 V version is rated for just 32 W, while the model under review (12 V) is rated for 54 W.


Since this power supply is designed for DIN-rail mounting, all the ventilation openings are on the top and bottom, which makes perfect sense.
There are plenty of openings, that’s for sure. They’ve made an effort.


The power supply’s dimensions compared with a “standard” matchbox :)


And here’s the full drawing from the manufacturer’s description.


The DIN-rail mounting mechanism is on the back. When installed in a panel, it sits at the bottom.


The SDR-120-24 had an almost entirely metal mechanism with a spring. This one is noticeably simpler: a plastic mechanism with two fixed positions.


An external inspection is all well and good, but I’m much more interested in looking inside. Every power supply has its own quirks, and it’s really hard to pass them by.
The power supply is very easy to open: two clips on the left and two on the right. Slip something flat between the two halves of the case, release the clips, and a few seconds later you have the two halves on the table.
By the way, the board and case are designed so that it’s very difficult to put anything in the wrong way, if it’s even possible at all.


The first thing that catches your eye is the unusual heatsink design. The heatsinks are effectively arranged for airflow, so the air passing through the power supply cools them quite efficiently.



There’s a proper input filter at the input.


1. Protection is provided by a fuse and a 470 V (peak) varistor. A thermistor for limiting inrush current is also visible nearby.
2. Filtering is handled by a common-mode choke and an X capacitor. Farther along, you can see the bridge rectifier, which has no heatsink here, unlike the one in the similarly rated EPS-65S.
3. The input capacitor has a capacitance of 120 µF, which is normal for 60 W, even with the wide input voltage range.
4. But the capacitor manufacturer is a bit concerning. I’m used to Mean Well using Nichicon, Rubycon, and Nippon capacitors. This time they’ve used Lelon. I have only come across these capacitors 2–3 times, so I don't have enough data to judge them, but there have been complaints about this brand on the forums, though in the context of their use on motherboards.


The key high-voltage transistor is hidden inside. Its marking is 13N60M2; the same part is used in the EPS-65S.


A couple more words about the heatsink design.
I originally planned to remove them, but changed my mind. On the side with the power components, they are held in place by those components, while on the other side they are soldered to the board using a press-fit copper pin. In short, as usual, the design isn't intended to make component removal easy.


The EMI suppression capacitors are on the other side. One of them is actually made up of two capacitors connected in series. They're positioned so that one is in one corner of the board (the small one on the right), and the other is diagonally opposite (you saw it in the previous photo).


The power supply's output section.


1. The output diode assembly is insulated from the heatsink. In my EPS-65S review, I criticized the designers for a "hole in the safety", but everything is fine here.
2. There's also a two-winding EMI suppression inductor on the output.


While "Chinese" power supplies are mostly made "from the same template", this one is the complete opposite: every power supply has its own quirks, sometimes strange ones.
For example, the designers used capacitors from the same manufacturer (rubycon), all with the same capacitance (1000 µF), but in different sizes, for some reason. In my opinion, there was no need for this, especially since they're all connected in parallel.
Also, one of the capacitors is covered with heat-shrink tubing, which is also puzzling.
The small brown capacitor is connected after the inductor and has a capacitance of 100 µF.


I have a minor comment about the terminal blocks—or, to be precise, the input terminal block. I also don't understand why the output one is the "elevator" type, while the input one is a standard type; it would have made more sense to use two identical ones. Also, the output terminal blocks are designed for a flat-blade screwdriver, while the input ones are universal.
Still, this doesn't affect how the power supply works, so let's just accept it as it is.



As usual, I have no complaints about the circuit board: everything is neat, clean, and well made.


There are unpopulated component locations in the output section. I figured out some of them: they're for additional Zener diodes in the overvoltage protection circuit. The rest remain a mystery.


The circuit design also had a few surprises in store.
1. The PWM controller is exactly the same as in the RPS-120-27, a 1293D065 (NCP1239). No questions there.
2. But the presence of a voltage regulator in the PWM controller's supply circuit is a little surprising. Judging by its 19–20 V regulation voltage, though, I think it's simply a supply voltage limiter.
The feedback optocoupler is above it; the optocoupler responsible for overvoltage protection is on the top side of the board.
3. But the absence of the usual TL431 in the feedback circuit is definitely unusual. Instead, there's an IC that apparently also includes an op-amp for the overload protection shunt. Unfortunately, I couldn't find a datasheet for this IC.
4. The current-limit input gets its voltage from an 8 mΩ shunt.


The block diagram is the same as for the EPS-65S and is nothing special: an input filter, PWM controller, output rectifier, and feedback and protection circuits.


The power supply schematic. It came out a little rough, but I tried to make sure it matched the actual circuit.
As I wrote, I still haven't figured out what the IC on the output is. If anyone knows, let me know.


And now for the tests.
The power supply provides output voltage adjustment over a range of 9 to 14.7 V. The adjustment is fairly smooth.


To evaluate efficiency and how the output voltage changes with output current, I tested the power supply in various modes, from no load up to 4.5 A—10% above the rated value.
The test was performed with an input voltage of about 225 V and 105–110 V.


The results were pleasantly surprising: output voltage stability is excellent, and efficiency reaches 88%, which is also pretty good.
I didn't like that the power supply makes a little noise at load currents between 100 and 500 mA.


I measured the output ripple amplitude using my main electronic load, which I use in most of my power supply reviews.
A filter consisting of a 47 µF electrolytic capacitor and a 0.1 µF ceramic capacitor is placed before the oscilloscope probe.


At no load, there are small periodic sawtooth spikes. The waveform on the left is at a high frequency, and the one on the right is at a low frequency.




The manufacturer specifies a maximum ripple of 120 mV for this power supply. At full load, I measured ripple up to 100 mV, which is close to the stated maximum.
I also noticed a few things:
1. Ripple amplitude depends very little on the load.
2. The power supply's operating frequency changes smoothly with the load.

The top pair of screenshots shows 100% load with 230 V input, at high and low frequencies.
The bottom pair shows the same thing, but with 105 V input.


According to the manufacturer, the load should be reduced if the ambient temperature rises above 45 degrees. In this respect, the power supply is rather “delicate,” since other models specify a limit of 50 or 60 degrees.
In my case, though, no derating is needed for the input voltage: it can be used at full output current with an input of 100 V or higher.


Unfortunately, I don't have an empty electrical panel at home, so I had to test the power supply by simply restricting its ventilation.


As usual, each test step took 20 minutes. The test at the higher input voltage lasted 1 hour 40 minutes, and at 110 V it lasted 1 hour 20 minutes.
The power supply impressed me with its temperatures. I could only get it to heat up noticeably under extreme conditions, at loads of 133% and 122% of its rated power. The air temperature under the cover was about 55 degrees, so I consider this test perfectly valid.
I was also surprised that the temperature at reduced input voltage wasn't much higher than at full input voltage. At one stage, I even double-checked that the input really was 110 V and not 230 V.


Thermal image just before the end of the test at 230 V input


And at 110 V. Here, though, the load current was 5.5 A rather than 6 A; I took a little pity on my “test subject.”


But the overload capability test was even more surprising—or, more specifically, the overload protection trip current.
First, the results were identical at both 230 V and 110 V input, which makes sense since the current is monitored on the output.
The power supply also maintains its output voltage right up until it shuts down. Once the load current drops, it automatically returns to normal operation.

What I didn't expect was a shutdown current of about 6.1 A. It turned out that I had been running the thermal test at the actual maximum current for this power supply—I just didn't know it at the time.


Overload shutdown in action. You can see that the output voltage remains stable until the protection trips.


I also checked the short-circuit protection along the way. It works as expected; if you keep the contacts shorted, the power supply attempts to restart every 1.5–2 seconds.
So, short-circuit protection on the high-voltage side and overload protection on the low-voltage side.


Video version of the review.



The tests are done; time to sum up.
The power supply maintains its output voltage accurately across the full load range, runs cool, operates reliably up to 6 A despite being rated for 4.5 A, and handles output short circuits correctly.
The design is well thought out, and the build quality is high.

There are a few caveats, though. Output ripple is within the manufacturer's specifications, but I think it could be lower.
I didn't like the design of the input terminal block, and the input capacitor looks a little suspicious. I don't know whether this capacitor is used only in this particular power supply or throughout the whole series. Let's hope it lasts a long time; I haven't had any complaints about Mean Well in this regard before.

That's all for now. As usual, I'm looking forward to your questions, and I hope you find the review useful.