Low-profile Mean Well LRS-350-24 power supply
Another power supply for my collection of Mean Wells: this is a model from the fairly well-known LRS series, rated at 350 W. Inspection, schematic, tests, conclusions—everything you’re used to :)
I’ve wanted to test something like this for a long time. I’ve had power supplies from this series before, but they were usually just passing through, and I never had time to write a review. This time, one of my regular readers lent me this unit to test—and, of course, take apart. What else would I do? Many thanks to him.
There are lots of different power supplies in this series, rated from 35 to 350 W. Only the most powerful model has active cooling; the rest don’t have a fan.
The specs list various protection features, automatic fan control, a load test after assembly, and a three-year warranty.
Like most branded power supplies, this model comes in a cardboard box, which is a little longer than the unit itself. That’s odd, since this is the most powerful model in the series.
The LRS-350 series includes eight models with output voltages of 3.3, 4.2, 5, 12, 15, 24, 36, and 48 V. It’s unusual to see a power supply with a 4.2 V output; I haven’t come across one before.
Mine is the 24 V model, so its maximum output current is 14.6 A. Note that although the series is rated at 350 W, only models with an output voltage of 12 V or higher actually deliver that much power. For example, the 3.3 V model is rated for just 200 W.
Externally, it’s a pretty standard power supply in an aluminum case. Since it has active cooling, there’s no perforated top cover, just a few holes.
There’s a switch on the side for selecting the input voltage range: 115/230 V.
The terminal block has no cover. On the left are the adjustment potentiometer and an LED indicating that output voltage is present.
It looks very neat: nothing is loose, and everything fits together well. There are four mounting holes on the bottom, plus two on each side.
The fan blows air in and is fairly noisy, but more on that later.
One of the key features of this series is its height: just 30 mm. In some situations, that can be the deciding factor when choosing a power supply.
All the dimensions are shown in the drawing, which I think makes them easier to understand.
But as you can imagine, the interesting stuff is inside. To get in, remove the four self-tapping screws and take off the cover.
Again, everything looks fairly neat. There’s an empty space where the fan is mounted.
Now, a closer look.
1. There is an input filter, but it’s a somewhat simplified version: an X capacitor and a common-mode choke.
2. Interestingly, although the board is marked LRS-350, the area around the fuse also has an LRS-200 version marking, and above it is an unclear name (or person’s name)—Edward.
3. Y2 safety capacitors are used. The exception is the capacitor connecting the output negative to the ground bus, but an ordinary high-voltage capacitor is safe to use here.
4. The board also has two thermistors and two varistors. The thermistors are placed after the bridge rectifier, one on each pole. The 240 V varistors are connected in parallel with the input filter capacitors.
5. The input capacitors are 560 µF, 200 V units connected in series, which makes sense because there’s a switch for selecting the input voltage range. The bridge rectifier is screwed to the case. It’s odd that cheap generic power supplies from AliExpress don’t do this; at most, they put a heatsink on it.
6. The inverter transistors are also screwed to the case, with silicone caps used for insulation.
The output section of the power supply. I happened to notice that the output inductor isn’t soldered directly to the board; it’s mounted on a separate piece of PCB material.
1, 2. The transformer is also low-profile. Judging by the primary winding connections, it’s wound in two stages: first one section, then the secondary windings, then the second section. The secondary winding is made from stranded wire.
3. The output diodes are also pressed against the case. All the retaining brackets are made from thick steel strip, and all the screws are secured.
4. There are four 470 µF, 35 V output capacitors, Rubycon ZLH series. A bit on the small side for a current of almost 15 A.
On the output side, you can see a fairly substantial busbar serving as a jumper.
I remove the remaining screws and take the board out of the case.
1. The clamping plate was screwed down firmly; it left marks on the silicone caps.
2. The inverter uses a pair of 18N60M2 transistors.
3. The input has a KBJ1008G bridge rectifier; its marking was hidden by the plate.
4. The output diode assemblies have a rather unusual configuration. They’re usually the same type, but here not only is one marked V20200C and specified as a High Voltage Trench MOS, while the other is the more familiar MBR20150, they’re also in different package styles.
There are many more components on the underside of the board.
I even had to take two extra photos, because it’s hard to make anything out even this way.
The high-voltage section. You can see that not all the components are installed. For example, four ceramic capacitors were planned in parallel with the high-voltage bus, but only one is fitted.
There are also unpopulated spots in the secondary section, including one clearly intended for a controller. Judging by the specifications of other power supplies, the marking near the diode assemblies (GSD), and the PCB traces, this is a synchronous rectifier controller. At high currents, even Schottky diodes are no longer enough.
Seeing two inverter transistors, you might assume the power supply uses a push-pull topology, but that’s not quite the case. Here, a single-ended NCP1252 from ON Semiconductor serves as the PWM controller. I was glad to see that Green-mode operation isn’t specified for it; at least, I couldn’t find any mention of it in the datasheet at a glance.
The power supply datasheet includes a block diagram showing the following set of protections:
1. OLP - overload protection
2. OTP - overtemperature protection
3. OVP - output overvoltage protection.
You can also see the fan control circuit, with a separate power rectifier.
At first, I didn’t plan to draw the schematic for this power supply, and tried looking for it online out of curiosity. No luck, though.
What’s more, on some well-known forum I saw someone ask for the schematic and get the reply: “There are no schematics, and there never will be.” That really got under my skin, so I decided: no, there will be a schematic.
After spending a ton of time redrawing it, I can say they really went all out. Here’s what stands out:
1. There’s a thermistor on each power line, and they’re located after the bridge rectifier, which is unusual.
2. There’s an input voltage monitoring circuit built around a separate transistor.
3. The PWM controller is powered by a voltage regulator.
4. The power supply uses a half-bridge topology, essentially a variation of a single-ended forward converter.
5. The inverter output transistors are driven through an isolation transformer.
6. There’s a triac in the primary circuit that disables the controller by shorting its supply. It’s controlled from the output section through an optocoupler and trips in the event of overheating or overvoltage.
7. The fan supply circuit has not only a separate rectifier, but also a separate 12.6 V voltage regulator.
8. The fan is controlled by a circuit built around a TL431, with a thermistor connected to it and mounted near the output inductor. There’s also a hysteresis circuit.
In any case, I think the schematic’s sheer size makes its complexity obvious. Of course, there may be errors, although I did my best to catch them. The component values and reference designators match the actual board.
Since the full schematic is hard to follow, I’ll show separately what a “half-bridge” is. In essence, it’s similar to a single-ended forward or flyback converter, but both ends of the primary winding are switched. This topology makes it possible to deliver more power while putting less stress on the inverter transistors.
I put everything back together, hoping I hadn’t accidentally knocked anything off while redrawing the schematic (some components were under the sealant). Everything’s fine, though: the power supply starts up, and the output is 24.2 V.
First, let’s check the output voltage adjustment.
1, 2. The output voltage can be adjusted from 21 to 29.1 V.
3, 4. But it turns out that if you try to set the output above 29.15 V, the power supply periodically trips into protection—or, more precisely, restarts when the protection kicks in. It looks like the protection circuit is kicking in: the thyristor shorts out the controller’s power supply, then there’s a pause for a “reboot,” and the whole thing starts over. The output voltage varies from 26.8 to 29.6 V.
The next tests will be under load. For those, I got an electronic load, a wattmeter, and a tester. I set the output to almost exactly 24 V, but I should note that the adjustment is quite coarse, and the trimmer turns very easily, so I recommend securing it with varnish or glue after adjustment.
The tests were run at 233 V. The very first one was measuring power consumption with no load, which came to about 1–1.1 W.
The output-voltage regulation test produced simply amazing results: across a load range of 0–115%, or 0–17 A, the output voltage varied by just 0.001 V!
Efficiency was even slightly higher than the stated 88%, coming in at about 90%. The small drop at the very end was caused by the fan switching on.
The graph covers the range from 1 to 18 A. At 19 A, the power supply went into protection and shut off the output voltage. The scale at the bottom shows current in amperes.
The overload test showed that the power supply shuts down at an output current of 18.82 A—and the current was exactly the same in all three attempts.
<img src="https://pic.mysku-st.ru/uploads/pictures/02/55/13/2019/12/20/4d249d.gif" alt="" />
The thermal test was carried out in three stages at load currents of 5, 10, and 15 A. Each stage lasted 20 minutes, so the test ran for a total of 1 hour.
Although my load can handle around 500–600 W for short periods, I had to use a second load for continuous operation. First, the original load ran at 5 A, then the second one was switched on at the same current, and in the final stage both loads ran at 7.5 A.
Before showing the thermal images, here are the results for output voltage versus current and temperature.
1. Everything is cold, no load: output is 24.005
2. After more than 20 minutes of operation at 10 A: still 24.005 at the output
3. After 1 hour of operation at 15 A: also 24.005 at the output
4. Remove the load. The output was initially still 24.005, but just a few seconds later it dropped to 24.003.
I’d say that’s an excellent result. The power factor was about 0.6–0.64 in the 50–400 W range.
A separate note on the fan. As I mentioned, it’s quite noisy, but the noise is “soft” and wasn’t too bothersome (unlike the noise from the two electronic loads). The fan’s control algorithm, though, is a little strange.
1. During the efficiency test, I gradually increased the load current over several minutes and recorded the measurements. The fan switched on when I reached 17 A.
2. After the one-hour thermal test, when I removed the load, the fan switched off immediately.
3. If you gradually increase the current while the power supply is hot, the fan starts at 5–7 W and reaches full speed at 17–20 W. It then keeps running at maximum speed.
4. Once it cools down, everything returns to normal. When the power supply is cold, the fan doesn’t start even at 15–16 A; it only switches on after the unit warms up.
I suspected that the temperature-sensing circuit’s supply voltage might depend on the load current, but the difference is quite small: the regulator’s output voltage fluctuates between 11.8 and 12.6 V as the main channel’s load current varies from 0 to 0.7 A. In the end, I just gave up trying to figure it out. It works, so I’m leaving it at that :)
1. Test start.
2. After 20 minutes
3. Another 20 minutes later.
End of the one-hour test. All the thermal images were taken “on the fly,” with the power supply running under load. The temperature, of course, immediately started to rise, so I opened the cover, quickly took a few photos, and then closed it again.
The output inductor gets the hottest. The transformer, by comparison, warms up moderately, reaching around 70–75 degrees.
Around the inverter transistors, the hottest components were the current-sense resistors, whose heat masked the radiation from the transistors, so I had to take a closer shot.
In any case, there was no sign of overheating, even though the power supply was loaded above its maximum current.
And the final test: measuring output-voltage ripple. The oscilloscope probe was connected directly to the power supply’s output terminals using a “spring” ground tip.
For this power supply, the manufacturer specifies a maximum ripple of 150 mV p-p. I tested it in four modes: 0, 5, 10, and 15 A, corresponding to roughly 33%, 66%, and 100% load.
Most of the ripple stayed within 40 mV, even at maximum current, but very short spikes were present in every mode. In this case, they can be ignored, since pulses this narrow are heavily attenuated by the wires to the load and its input capacitors. If you want it to look “nice,” even a small inductor (a few µH) and a 470–1000 µF capacitor will almost completely eliminate them.
The input filter capacitance in this power supply is 280 µF at 350 W, so I decided to check how well it attenuates ripple at 100 Hz.
At maximum power, the ripple was about 20–30 mV peak-to-peak, which is also very good. And yes, the first and second screenshots are in the right order: at 5 A, the power supply produces less high-frequency noise than with no load.
The title links to the Kharkiv store Kosmodrom, but the advantage of branded power supplies is that they’re identical, so you’ll usually get the same unit if you buy it elsewhere.
For example, this power supply is on AliExpress — link
And on Taobao — link
There’s also a power supply from Sanpu, advertised as an equivalent to Mean Well — link
Although in most cases it’s easier and cheaper to buy a Mean Well locally than from China.
Yes, if you’re buying from China, be careful not to accidentally buy a clone, like the ones shown below. In the first case, it really is a clone, just with lower-quality components. In the second, the manufacturer is merely using the same model name; inside, it’s an ordinary power supply based on a TL494.
And make sure to read the full model name, because the logo can look almost identical.
So, here’s the bottom line.
The power supply performed excellently throughout all the tests. It maintained excellent output voltage stability across the full load-current range and during the thermal soak test—in fact, it holds the voltage to within 0.002–0.003 V in every operating mode.
There’s no overheating, and the fan is controlled properly. I was a little surprised, though, that the controller switches it off once the load is completely removed from a warmed-up power supply, but turns it on again when the load reaches just 5–7 W.
Ripple is also generally fine, apart from some very short spikes.
Likewise, I have no complaints about the quality of the components or the design. Branded components are used, and all the power components are attached to the case, which acts as a heatsink. There’s an input filter, and varistors are fitted as well.
At this point, I’m even starting to regret buying a no-name 600 W power supply for my RD6006 converter. For about the same money, I could have bought a pair of LRS-350-36 units, connected them in series, and gotten up to 700 W in roughly the same space. But they would have been high-quality branded power supplies. What’s more, I wouldn’t have had to wait for them to arrive from China—I could simply have stopped by a store on the way and bought them.
That’s all for today. I hope you found this useful, and thanks again to Alexander for providing the sample.
I’ve wanted to test something like this for a long time. I’ve had power supplies from this series before, but they were usually just passing through, and I never had time to write a review. This time, one of my regular readers lent me this unit to test—and, of course, take apart. What else would I do? Many thanks to him.
There are lots of different power supplies in this series, rated from 35 to 350 W. Only the most powerful model has active cooling; the rest don’t have a fan.
The specs list various protection features, automatic fan control, a load test after assembly, and a three-year warranty.
Like most branded power supplies, this model comes in a cardboard box, which is a little longer than the unit itself. That’s odd, since this is the most powerful model in the series.
The LRS-350 series includes eight models with output voltages of 3.3, 4.2, 5, 12, 15, 24, 36, and 48 V. It’s unusual to see a power supply with a 4.2 V output; I haven’t come across one before.
Mine is the 24 V model, so its maximum output current is 14.6 A. Note that although the series is rated at 350 W, only models with an output voltage of 12 V or higher actually deliver that much power. For example, the 3.3 V model is rated for just 200 W.
Externally, it’s a pretty standard power supply in an aluminum case. Since it has active cooling, there’s no perforated top cover, just a few holes.
There’s a switch on the side for selecting the input voltage range: 115/230 V.
The terminal block has no cover. On the left are the adjustment potentiometer and an LED indicating that output voltage is present.
It looks very neat: nothing is loose, and everything fits together well. There are four mounting holes on the bottom, plus two on each side.
The fan blows air in and is fairly noisy, but more on that later.
One of the key features of this series is its height: just 30 mm. In some situations, that can be the deciding factor when choosing a power supply.
All the dimensions are shown in the drawing, which I think makes them easier to understand.
But as you can imagine, the interesting stuff is inside. To get in, remove the four self-tapping screws and take off the cover.
Again, everything looks fairly neat. There’s an empty space where the fan is mounted.
Now, a closer look.
1. There is an input filter, but it’s a somewhat simplified version: an X capacitor and a common-mode choke.
2. Interestingly, although the board is marked LRS-350, the area around the fuse also has an LRS-200 version marking, and above it is an unclear name (or person’s name)—Edward.
3. Y2 safety capacitors are used. The exception is the capacitor connecting the output negative to the ground bus, but an ordinary high-voltage capacitor is safe to use here.
4. The board also has two thermistors and two varistors. The thermistors are placed after the bridge rectifier, one on each pole. The 240 V varistors are connected in parallel with the input filter capacitors.
5. The input capacitors are 560 µF, 200 V units connected in series, which makes sense because there’s a switch for selecting the input voltage range. The bridge rectifier is screwed to the case. It’s odd that cheap generic power supplies from AliExpress don’t do this; at most, they put a heatsink on it.
6. The inverter transistors are also screwed to the case, with silicone caps used for insulation.
The output section of the power supply. I happened to notice that the output inductor isn’t soldered directly to the board; it’s mounted on a separate piece of PCB material.
1, 2. The transformer is also low-profile. Judging by the primary winding connections, it’s wound in two stages: first one section, then the secondary windings, then the second section. The secondary winding is made from stranded wire.
3. The output diodes are also pressed against the case. All the retaining brackets are made from thick steel strip, and all the screws are secured.
4. There are four 470 µF, 35 V output capacitors, Rubycon ZLH series. A bit on the small side for a current of almost 15 A.
On the output side, you can see a fairly substantial busbar serving as a jumper.
I remove the remaining screws and take the board out of the case.
1. The clamping plate was screwed down firmly; it left marks on the silicone caps.
2. The inverter uses a pair of 18N60M2 transistors.
3. The input has a KBJ1008G bridge rectifier; its marking was hidden by the plate.
4. The output diode assemblies have a rather unusual configuration. They’re usually the same type, but here not only is one marked V20200C and specified as a High Voltage Trench MOS, while the other is the more familiar MBR20150, they’re also in different package styles.
There are many more components on the underside of the board.
I even had to take two extra photos, because it’s hard to make anything out even this way.
The high-voltage section. You can see that not all the components are installed. For example, four ceramic capacitors were planned in parallel with the high-voltage bus, but only one is fitted.
There are also unpopulated spots in the secondary section, including one clearly intended for a controller. Judging by the specifications of other power supplies, the marking near the diode assemblies (GSD), and the PCB traces, this is a synchronous rectifier controller. At high currents, even Schottky diodes are no longer enough.
Seeing two inverter transistors, you might assume the power supply uses a push-pull topology, but that’s not quite the case. Here, a single-ended NCP1252 from ON Semiconductor serves as the PWM controller. I was glad to see that Green-mode operation isn’t specified for it; at least, I couldn’t find any mention of it in the datasheet at a glance.
The power supply datasheet includes a block diagram showing the following set of protections:
1. OLP - overload protection
2. OTP - overtemperature protection
3. OVP - output overvoltage protection.
You can also see the fan control circuit, with a separate power rectifier.
At first, I didn’t plan to draw the schematic for this power supply, and tried looking for it online out of curiosity. No luck, though.
What’s more, on some well-known forum I saw someone ask for the schematic and get the reply: “There are no schematics, and there never will be.” That really got under my skin, so I decided: no, there will be a schematic.
After spending a ton of time redrawing it, I can say they really went all out. Here’s what stands out:
1. There’s a thermistor on each power line, and they’re located after the bridge rectifier, which is unusual.
2. There’s an input voltage monitoring circuit built around a separate transistor.
3. The PWM controller is powered by a voltage regulator.
4. The power supply uses a half-bridge topology, essentially a variation of a single-ended forward converter.
5. The inverter output transistors are driven through an isolation transformer.
6. There’s a triac in the primary circuit that disables the controller by shorting its supply. It’s controlled from the output section through an optocoupler and trips in the event of overheating or overvoltage.
7. The fan supply circuit has not only a separate rectifier, but also a separate 12.6 V voltage regulator.
8. The fan is controlled by a circuit built around a TL431, with a thermistor connected to it and mounted near the output inductor. There’s also a hysteresis circuit.
In any case, I think the schematic’s sheer size makes its complexity obvious. Of course, there may be errors, although I did my best to catch them. The component values and reference designators match the actual board.
Since the full schematic is hard to follow, I’ll show separately what a “half-bridge” is. In essence, it’s similar to a single-ended forward or flyback converter, but both ends of the primary winding are switched. This topology makes it possible to deliver more power while putting less stress on the inverter transistors.
I put everything back together, hoping I hadn’t accidentally knocked anything off while redrawing the schematic (some components were under the sealant). Everything’s fine, though: the power supply starts up, and the output is 24.2 V.
First, let’s check the output voltage adjustment.
1, 2. The output voltage can be adjusted from 21 to 29.1 V.
3, 4. But it turns out that if you try to set the output above 29.15 V, the power supply periodically trips into protection—or, more precisely, restarts when the protection kicks in. It looks like the protection circuit is kicking in: the thyristor shorts out the controller’s power supply, then there’s a pause for a “reboot,” and the whole thing starts over. The output voltage varies from 26.8 to 29.6 V.
The next tests will be under load. For those, I got an electronic load, a wattmeter, and a tester. I set the output to almost exactly 24 V, but I should note that the adjustment is quite coarse, and the trimmer turns very easily, so I recommend securing it with varnish or glue after adjustment.
The tests were run at 233 V. The very first one was measuring power consumption with no load, which came to about 1–1.1 W.
The output-voltage regulation test produced simply amazing results: across a load range of 0–115%, or 0–17 A, the output voltage varied by just 0.001 V!
Efficiency was even slightly higher than the stated 88%, coming in at about 90%. The small drop at the very end was caused by the fan switching on.
The graph covers the range from 1 to 18 A. At 19 A, the power supply went into protection and shut off the output voltage. The scale at the bottom shows current in amperes.
The overload test showed that the power supply shuts down at an output current of 18.82 A—and the current was exactly the same in all three attempts.
<img src="https://pic.mysku-st.ru/uploads/pictures/02/55/13/2019/12/20/4d249d.gif" alt="" />
The thermal test was carried out in three stages at load currents of 5, 10, and 15 A. Each stage lasted 20 minutes, so the test ran for a total of 1 hour.
Although my load can handle around 500–600 W for short periods, I had to use a second load for continuous operation. First, the original load ran at 5 A, then the second one was switched on at the same current, and in the final stage both loads ran at 7.5 A.
Before showing the thermal images, here are the results for output voltage versus current and temperature.
1. Everything is cold, no load: output is 24.005
2. After more than 20 minutes of operation at 10 A: still 24.005 at the output
3. After 1 hour of operation at 15 A: also 24.005 at the output
4. Remove the load. The output was initially still 24.005, but just a few seconds later it dropped to 24.003.
I’d say that’s an excellent result. The power factor was about 0.6–0.64 in the 50–400 W range.
A separate note on the fan. As I mentioned, it’s quite noisy, but the noise is “soft” and wasn’t too bothersome (unlike the noise from the two electronic loads). The fan’s control algorithm, though, is a little strange.
1. During the efficiency test, I gradually increased the load current over several minutes and recorded the measurements. The fan switched on when I reached 17 A.
2. After the one-hour thermal test, when I removed the load, the fan switched off immediately.
3. If you gradually increase the current while the power supply is hot, the fan starts at 5–7 W and reaches full speed at 17–20 W. It then keeps running at maximum speed.
4. Once it cools down, everything returns to normal. When the power supply is cold, the fan doesn’t start even at 15–16 A; it only switches on after the unit warms up.
I suspected that the temperature-sensing circuit’s supply voltage might depend on the load current, but the difference is quite small: the regulator’s output voltage fluctuates between 11.8 and 12.6 V as the main channel’s load current varies from 0 to 0.7 A. In the end, I just gave up trying to figure it out. It works, so I’m leaving it at that :)
1. Test start.
2. After 20 minutes
3. Another 20 minutes later.
End of the one-hour test. All the thermal images were taken “on the fly,” with the power supply running under load. The temperature, of course, immediately started to rise, so I opened the cover, quickly took a few photos, and then closed it again.
The output inductor gets the hottest. The transformer, by comparison, warms up moderately, reaching around 70–75 degrees.
Around the inverter transistors, the hottest components were the current-sense resistors, whose heat masked the radiation from the transistors, so I had to take a closer shot.
In any case, there was no sign of overheating, even though the power supply was loaded above its maximum current.
And the final test: measuring output-voltage ripple. The oscilloscope probe was connected directly to the power supply’s output terminals using a “spring” ground tip.
For this power supply, the manufacturer specifies a maximum ripple of 150 mV p-p. I tested it in four modes: 0, 5, 10, and 15 A, corresponding to roughly 33%, 66%, and 100% load.
Most of the ripple stayed within 40 mV, even at maximum current, but very short spikes were present in every mode. In this case, they can be ignored, since pulses this narrow are heavily attenuated by the wires to the load and its input capacitors. If you want it to look “nice,” even a small inductor (a few µH) and a 470–1000 µF capacitor will almost completely eliminate them.
The input filter capacitance in this power supply is 280 µF at 350 W, so I decided to check how well it attenuates ripple at 100 Hz.
At maximum power, the ripple was about 20–30 mV peak-to-peak, which is also very good. And yes, the first and second screenshots are in the right order: at 5 A, the power supply produces less high-frequency noise than with no load.
The title links to the Kharkiv store Kosmodrom, but the advantage of branded power supplies is that they’re identical, so you’ll usually get the same unit if you buy it elsewhere.
For example, this power supply is on AliExpress — link
And on Taobao — link
There’s also a power supply from Sanpu, advertised as an equivalent to Mean Well — link
Although in most cases it’s easier and cheaper to buy a Mean Well locally than from China.
Yes, if you’re buying from China, be careful not to accidentally buy a clone, like the ones shown below. In the first case, it really is a clone, just with lower-quality components. In the second, the manufacturer is merely using the same model name; inside, it’s an ordinary power supply based on a TL494.
And make sure to read the full model name, because the logo can look almost identical.
So, here’s the bottom line.
The power supply performed excellently throughout all the tests. It maintained excellent output voltage stability across the full load-current range and during the thermal soak test—in fact, it holds the voltage to within 0.002–0.003 V in every operating mode.
There’s no overheating, and the fan is controlled properly. I was a little surprised, though, that the controller switches it off once the load is completely removed from a warmed-up power supply, but turns it on again when the load reaches just 5–7 W.
Ripple is also generally fine, apart from some very short spikes.
Likewise, I have no complaints about the quality of the components or the design. Branded components are used, and all the power components are attached to the case, which acts as a heatsink. There’s an input filter, and varistors are fitted as well.
At this point, I’m even starting to regret buying a no-name 600 W power supply for my RD6006 converter. For about the same money, I could have bought a pair of LRS-350-36 units, connected them in series, and gotten up to 700 W in roughly the same space. But they would have been high-quality branded power supplies. What’s more, I wouldn’t have had to wait for them to arrive from China—I could simply have stopped by a store on the way and bought them.
That’s all for today. I hope you found this useful, and thanks again to Alexander for providing the sample.
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This model is included in the summary table: Comparison of power supplies: ripple, efficiency, and temperature rise
The figures from this review are in the measurement database: Power supplies
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