Adjustable converter RD6024,

The new RD6024 converter from RuiDeng has finally made its way to me. Yes, I’d been waiting for it ever since it was announced and the first model in the series, the RD6006, went on sale.

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Back when the RD6006 first appeared, there was already word that models 6012, 6018, and 6024 were also planned. I don’t think the P series had been mentioned at the time, but the idea was the same: the 6024 would be the most powerful model, at least in this lineup.
To explain where this information came from: all the announced models were listed in a certificate posted on the seller’s page. Though I’ve never seen the RD6006-B model.



As soon as I saw that the converter was available, I messaged the manager and asked them to send one over. A little while later, I picked up the now-familiar Styrofoam box at the post office. Yes, the packaging is just as before: good and sturdy. Five stars.


Before getting into the review, here’s a list of all the Ruideng converters I’ve tested:
DPH5005
DPS8005
DPS5020
RD6006
RD6012
RD6018
RD6006P
RD6012P

Comparison of the specifications of all converter models.



Inside is the usual set of accessories—well, almost the usual set, since there are a few small changes:
1. converter
2. WiFi module (sold separately)
3. temperature sensor
4. fuse
5. a pair of terminals
6. another pair of terminals



A closer look.
1–2. The WiFi module and temperature sensor are identical to the ones included with all the previous models.
3. A pair of fork terminals, plus a fuse rated for 30 A. By the way, I don’t think these types of fuses are very safe to use with DC. But the higher the current and voltage rating of the power supply, the more problems you can run into, so personally, I’d install a large fuse on the input, rated for the same current.
4. These terminals, on the other hand, weren’t included before.


The converter itself looks, at first glance, exactly the same as before.


And yes, it’s the same display and the same buttons, with the same number and functions. I don’t even see the point of explaining what each one does, since this is already my sixth review of a converter in this series. There’s only been one change to the controls over the years: the 6012P added a switch between the 0–6 A and 0–12 A ranges.


But there are some differences after all, even if they’re minor.
For example, the 6024’s output terminals have been changed. They’re noticeably larger now, and the screw-on sections can be removed easily.


I noticed the second significant difference while unpacking the converter: its weight. The new model is considerably heavier, and you can feel it right away.
I couldn’t resist putting them on the scales. The RD6012 is on the left, the RD6024 on the right. The first one also has a battery installed, but that’s negligible.
The new converter weighs 120 grams more.


Let’s take a look inside.
At a quick glance, I didn’t notice any significant differences from the previous RD6018. I don’t think the board layout has changed much, either.


And this is why the included terminals are useful: unlike all the previous models, this one has a different type of input terminal. They’re screw terminals now, and the ones included in the box let you use detachable connectors.
There’s a small capacitor between the terminals, but that’s not what I wanted to mention. Once again, these terminals are awkward to use. Before, the wire would often simply slip out of the terminal block; here, you’ll have to wrestle with turning the screw, the terminal, and the wire.


1. The input has a genuinely large inductor wound with wire about 2.2–2.3 mm in diameter.
2. There’s a reverse-polarity protection transistor on the input. By the way, I should remove these from my own converters. To the right is the holder for one of the fuses, but as before, the original fuses are soldered in. I'm starting to get a little concerned about this small holder at currents of 24 A, especially compared with the input terminals.
3. There are three input capacitors, rated at 470 µF. The RD6018 had two, so this looks like straightforward scaling in proportion to the power rating.
4. Here's another change: there's a small board under the inductor.


The input auxiliary voltage converters look unchanged to me.


The PWM controller is the same as before, a TL594C. I think it's been unchanged since the DPS series models.


1. As far as I can tell, the transistor drive circuitry in the converter hasn't changed at all compared with the 6012 and 6018.
2. There are three current-sense shunts, as on the 6018, but these are 10 mΩ rather than 15 mΩ. That makes sense; once again, we see straightforward scaling.
3. Apart from the small output components, there's a pair of 470 µF capacitors, just like on the 6018.
4. But there is one change: the 6018 had five output capacitors, two rated at 470 µF and three smaller ones. This one has four capacitors; an inductor now sits where one of the smaller capacitors used to be (though not in its place electrically).
5. The relay is the same as on the 6018.
6. There's a new jumper of some sort. The board is relatively clean: there are a few traces of flux from soldering the large components, but overall the work is neat.


The converter comes apart just like all the previous ones: desolder the terminals and remove the board.
The terminals are noticeably more substantial. I could feel it even while desoldering them; they took much longer to heat up.


The input converter section is a fairly critical area, so I'll take a more detailed photo just in case.


As I mentioned, there's a small board under the input inductor that wasn't present in the previous models. A quick look at how it's connected suggests that it's probably an input overvoltage protection board that switches the power supply to the auxiliary converters.


The power inductor is really big, noticeably larger than the one in the 6018, and especially the 6012. The core's outer diameter is about 33 mm, the wire is around 1.3–1.4 mm, and the winding uses two wires.


There are jumpers on the underside too. Otherwise, it looks much like the 6018.


1. As before, there's a heatsink under the auxiliary PWM controller. I think it first appeared in the 6018 and has been used in all subsequent models.
2. Since the converter has a synchronous rectifier, it uses two power transistors. As before, these are HY3210s, so there's no change in this respect compared with the 6018 and 6012.


The control board looks the same as before.


Though we should clarify what “same as before” means here: the board looks like the ones in the 6006P and 6012P models, while the 6018 and earlier models had a slightly different board.
The thing is, historically the models came in this order: 6006, 6012, 6018, 6006P, 6012P. The board changed with the 6006P.


A nearly exclusive photo: all four non-hybrid converter models side by side—RD6006, RD6012, RD6018, and RD6024.


I put everything back together and move on to testing. The first power-up showed that, at least, the converter was pretending to work, which meant I probably hadn't broken anything :)


The control menu is no different from the previous models, except that the output power limit is higher, which makes sense.


Even the incorrect order of parameter names in the Russian translation has been preserved. What's telling is that the English, Chinese, French, and German versions are all fine; the error is only in Russian. I mention this in every review, but the manufacturer keeps carrying it over from one model to the next with admirable persistence.


Test zero: the converter's no-load power consumption at different input voltages.


This isn't really a test at all, more of an observation—and I'm putting it here out of order so I don't forget. During testing, I noticed that the time on the RD6018 converter differs from the one I just set on the RD6024. I compared them, and it turns out that since my review of the 6018 model (October 26, 2020), the clock has drifted by 8 minutes. Not exactly impressive accuracy.


Test one: input voltage measurement accuracy. From here on, the photos are just there to supplement the conclusions, nothing more.

There’s a slight overreading, about 0.1%, but I don’t think that’s critical for a parameter that isn’t all that important to begin with.


Test two: output voltage setting and measurement accuracy.
This one’s straightforward: I change the output voltage in steps. The multimeter shows the actual output, while the converter’s display shows what it measures itself.

I set the voltage using the 1-2-5 sequence: 0.01, 0.02, 0.05, 0.1...20, 50 V.

The spec is 0.3%+3 digits, and I have no complaints about either the setting accuracy or the measurement accuracy.


Test three: current setting and measurement accuracy. The method is the same as in the previous test.

The spec is 0.5%+5 digits. As you can see, across the entire range up to 5 A, the converter slightly underreads the output current, but still stays within the stated specs. My only real complaint is its performance at very low values. Expecting high accuracy below 100 mA from a converter rated for up to 24 A would be rather optimistic, but even there it behaves reasonably well.


The maximum current my multimeter can measure is 10 A. I’ve measured 12–13 A briefly, but even that is only 50% of this converter’s rated current.
I initially thought of using a clamp meter to measure the current, but its accuracy is poor, so I took the simpler route and used a 1 mΩ, 0.5% current shunt. That means 1 mV on the multimeter display corresponds to 1 A through the shunt.


First I measured at the same 10 A as before. This time the result was slightly higher: 9.997 versus 9.971. Hard to say which one is fibbing more, and I don’t think the difference is particularly significant anyway.

I checked several current levels, but I think a couple of readings are enough to assess it: 18 A and 24.1 A. The first looks fine overall, while the second is clearly underread. The converter’s own ammeter shows a deviation in the opposite direction. I wouldn’t call it terrible, but I expected a little better.


Test four: output voltage versus load.
I tested at two output voltages, 5 and 12 V. The results are excellent. RD60xx converters pass this test without any trouble. But there’s a catch, as I mentioned before and will say again: without a four-wire connection, all this accuracy in setting and maintaining the voltage is meaningless, because a meter of cable can easily wipe out the claimed 0.3%+3 digits :(


Test five: minimum input/output voltage difference.
I tested with input voltages of 24 and 40 V. At 24 V, the load current was 12 and 18 A; at 40 V, I tested only at 18 A.
At the lower input voltage, the difference was 2.1/2.3 V; at the higher voltage, it was 3.4 V. I think you’ll be safe allowing 6–7 V of headroom when choosing a power supply.

During testing, the power supply feeding the unit under test went into protection several times, causing the converter to reboot. At one point I noticed it had entered a strange mode: the screen was dark, the output was enabled, but there was no output voltage. I wouldn’t consider this an intended operating condition, so this behavior may be normal, but I couldn’t leave it unmentioned.


Test six: ripple.

Due to some circumstances, I couldn’t check the ripple at relatively high power, but I’ll try to fix that and add the information to the review if possible.

First, a test at an output voltage of 12.5 V and load currents of 0, 8, 16, and 24 A.

The specs state 100 mV at currents up to 12 A and up to 150 mV at 24 A. Interestingly, the 6012 and 6018 series converters are specified at up to 250 mV, most likely because the 6024 has an additional inductor on the output.

Overall, not bad at all—very good, even excellent, if it weren’t for the short “spikes.” The probe was connected directly, without a C+C filter.



I used a different load here. It introduced some interference, but let me capture waveforms at up to 600 W.
Below are the ripple waveforms for these operating conditions:
1. 5 V, 24 A
2. 20 V, 24 A
3. 30 V, 20 A
4. 48 V, 12.5 A.

Everything is the same as before: ripple amplitude in the main section is very low, but the “spikes” spoil the whole picture.


Test seven: transient response. Since the conditions for this test are unchanged, I’ll just copy the description from the previous review.
1, 2. Applying and removing 5 V at the converter output with no load.
3, 4. Response to connecting/disconnecting a load. The output was set to 12 V, with a 30 Ω resistor connected continuously and a 3.3 Ω resistor connected in parallel with it (or disconnected). So this shows the response to a current step from 0.4 to 4 A and from 4 to 0.4 A.
5. Transition from CV to CC mode: voltage 15 V, load current 4.5 A, current limit set to 3 A.
6. The same load and settings, but in the opposite direction, from CC to CV.

No complaints. The transition from CV to CC is a little slow, but I don’t consider that a drawback.


The traditional “soldering iron” test.
Of course, these aren’t Series P converters, but the results are still pretty good—at least better than with the 6018-series converter.

Overall, in terms of both ripple and transient response, the 6024 clearly outperforms both the 6012 and the 6018, so adding the inductor was mostly a positive change.


Test eight: evaluating the converter’s efficiency.
I tested it under almost the same conditions as the 6018: output voltages of 5, 12, 24, and 36 V. However, I was only able to supply 24 A in all but the last test; the primary power supply went into protection.

The results were:
Output voltage — efficiency — losses
5 V - 80.8% - 28.58 W
12 V - 90.7% - 29.48 W
24 V - 95.0% - 29.72 W
36 V - 97.1% - 21.96 W


Out of curiosity, I compared it with the 6018 at the same load current to see how replacing some of the power components affected efficiency.

Output voltage — efficiency — losses (results for the 6018 model at the same current)
5 V - 82.3% - 19.46 W (83.3% - 18.07 W)
12 V - 91.6% - 19.77 W (92.0% - 18.6 W)
24 V - 95.7% - 19.32 W (95.8% - 19.13 W)
36 V - 97.1% - 18.93 W (97.2% - 18.12 W)

Strange, but its efficiency turned out to be slightly lower than the 6018’s. For some reason, I expected the opposite.


To evaluate the heating, I decided to power the converter from a different power supply. At first I wanted to measure efficiency, but then realized it wouldn’t work because I’d run into the multimeter’s current limit again, and I didn’t want to rig up another current-sense shunt.


But I did check two things:
1. The converter can deliver more than 1 kW without any problems, but the power supply’s LED starts blinking and it goes into protection after a few seconds.
2. The maximum output power at which the power supply shown can run continuously is about 980 W.

I suspect the power supply monitors current separately for each pair of output terminals, rather than the total current. I tried connecting them in parallel, but saw no difference. I’ll investigate further.


A long-duration heating test is technically difficult. Even three electronic loads connected at the same time could only handle about 50% of the power, and they overheated fairly quickly even at that level.
The only thing is


Still, I was able to assess the heating, and more importantly, identify the main hotspots:
1. The fuses get noticeably hot, as expected. It was also expected that they would get even hotter if installed in holders.
2. The auxiliary converter section. The XL7015 gets the hottest, but since this isn’t affected by output power and it has a heatsink underneath, everything is fine.
3. The current-sense shunts do heat up, but remain within acceptable limits. Calculations also show that at 24 A, their combined dissipation will be 1.9 W.
4. The output filter inductor gets warm, as expected, but the thermal image suggests it doesn’t get very hot.
5. The converter’s power inductor, unfortunately, was tested at 20 A, but the total output power was only 50%, so the inductor was operating under a light load and barely got warm.



After testing, I installed the converter in its original enclosure, which I showed in my review of the RD6012. I used an 800 W power supply to power it.
I also have an enclosure intended for the 6006 model (I showed it here). It cost more because it came with a fan and a control board, but while tinkering with the enclosures, I noticed a difference in the weight of their covers.
And yes, it turns out the cover for the 6006 enclosure weighs more than twice as much as the one for the 6012–6024 models. Unexpected.


Everything looks neat, but unfortunately the enclosure is very deep. One possible solution is to use compact, high-power supplies, for example, two or three Mean Well EPP-series units, like these, but with a lower voltage and connected in series. Unfortunately, the price isn't appealing :(
To avoid overloading the power supply—which, as it turns out, shuts down even before reaching its stated 800 W—I set the converter's output power limit to 700 W.
So I can get up to 29 V at 24 A, or up to 61 V, but then the current has to be reduced linearly to 11.5 A. More precisely, the converter does that itself.

I'm happy with the current setup, although of course I've been thinking about fitting a power supply into this enclosure so the converter can run "flat out"—that is, at almost 1500 W of output power.


RD60xx series timeline
I originally planned to write this differently, but a timeline will do. First, here's a general view of all the RD-series converters. I think it's clear that there are no differences between them, and in my opinion, that's a great idea. Neither the controls nor the overall dimensions change, which ensures a high degree of standardization.


The converters were released roughly in this order (review publication dates):
RD6006 - November 2019
RD6012 - July 2020
RD6018 - October 2020
RD6006P - April 2021
RD6012P - December 2021
RD6024 -


The lineup was quite logical until the P series came along, which was a pleasant surprise. The model reviewed here rounds out the range.


So, what can I say about this converter?
On the one hand, it's still the same RD6018, with a few modifications: the inductors and shunts have been replaced, and an additional input capacitor has been added. The only change beyond the usual scaling-up is the addition of an inductor to reduce ripple. Otherwise, it's the same RD6018; even the power-stage transistors are unchanged, not to mention the control and auxiliary power supply sections.
Actually, there's one more change, and it's partly cosmetic: they fitted more powerful output terminals.

Of course, it's great that the converter can deliver up to 24 A at the output while providing excellent voltage-setting accuracy and very good current-setting accuracy. But there's "one catch": the lack of a four-wire connection to the load completely negates the voltage-setting and regulation accuracy.

In short, in my opinion, this converter is a decent alternative to the 6012 and 6018 models, but with a current of 24 A.

Now, as for expanding the lineup further. I haven't discussed this with the manager yet, but personally, I don't think there's much point in aiming for a model like the 6030: demand would decline. Models like the 120xx are also in low demand, while the P series has hit a thermal limit. So, for the umpteenth time, I'll suggest that RuiDeng get into designing an electronic load. After all, they could essentially reuse the same control section, DAC, and ADC. The manufacturer objected that it would be expensive because it needs a powerful power stage. I replied that no cooling system is needed; people can choose one themselves. In short, I suggested ways to optimize the design and increase its appeal to electronics hobbyists, and offered to help with consultations, but none of my suggestions were met with much enthusiasm...


That's all for today. I hope you found the review useful, and as usual, I'd be glad to hear your comments and suggestions for the manufacturer.


The store provided a 5/80 coupon. I don't know how it works; here's the link.
This converter also sometimes turns up at a good price on Banggood - link.